Prévia do material em texto

ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 1
Aquatic Biodiversity in Latin America
Biodiversidad Acuática en América Latina
Volume 1
Amazon Fish Parasites
(Second edition)
Volumen 1
Parásitos de Peces Amazónicos
(Segunda edición)
2 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
BIODIVERSIDAD ACUÁTICA EN AMÉRICA LATINA
Volumen 1
PARÁSITOS DE PECES
AMAZÓNICOS
(Segunda edición)
por
Vernon E. Thatcher
Lector Científico a los Editores:
František Moravec
Editores de la Serie:
Joachim Adis, Jorge R. Arias,
Guillermo Rueda-Delgado & Karl Matthias Wantzen
Sofia–Moscow
2006
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 3
AQUATIC BIODIVERSITY IN LATIN AMERICA
Volume 1
AMAZON FISH
PARASITES
(Second edition)
by
Vernon E. Thatcher
Scientific Reader to the Editors:
František Moravec
Series Editors:
Joachim Adis, Jorge R. Arias,
Guillermo Rueda-Delgado & Karl Matthias Wantzen
Sofia–Moscow
2006
4 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
Front cover:
Nerocila armata (Cymothoidae, Isopoda) and Amazon River near Manaus, Brazil
(photos: V.E. Thatcher, W.J. Junk; design: Zheko Aleksiev & Elke Bustorf)
© PENSOFT Publishers
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or
transmitted in any form by any means, electronic, mechanical, photocopying, recording or
otherwise, without the prior written permission of the copyright owner.
Aquatic Biodiversity in Latin America Vol. 1
ISSN 1312-7276
First published 2006
ISBN-10: 954-642-258-4
ISBN-13: 978-954-642-258-3
Pensoft Publishers
Geo Milev Str. 13a, Sofia 1111, Bulgaria
pensoft@mbox.infotel.bg
www.pensoft.net
Printed in Bulgaria, March 2006
AQUATIC BIODIVERSITY IN LATIN AMERICA
BIODIVERSIDAD ACUÁTICA EN AMÉRICA LATINA
VOLUMEN 1.
PARÁSITOS DE PECES AMAZÓNICOS
(Segunda edición)
por
Vernon E. Thatcher
Lector Científico a los Editores:
František Moravec
VOLUME 1.
AMAZON FISH PARASITES
(Second edition)
by
Vernon E. Thatcher
Scientific Reader to the Editors:
František Moravec
Series Editors/Editores de la Serie:
Joachim Adis, Jorge R. Arias, Guillermo Rueda-Delgado & Karl Matthias Wantzen
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 5
AQUATIC BIODIVERSITY IN LATIN AMERICA
BIODIVERSIDAD ACUÁTICA EN AMÉRICA LATINA
Series Editors: Joachim Adis, Jorge R. Arias,
Guillermo Rueda-Delgado & Karl Matthias Wantzen
Biodiversity is a key word in science and global management schemes, however very few
people are able to identify the species and their ecology that make up “biodiversity”. For
many years, researchers and students from numerous countries complain about the lack of
“tools” to identify aquatic invertebrates from Latin America. Keys found in accepted
entomological textbooks are mostly highly limited, superficial and rarely cover Neotropical
biota in sufficient detail. On the other hand, specialized information on taxonomy or ecology
is scattered throughout the literature in many single publications.
An international team of editors have combined their efforts with Pensoft Publishers
to launch a new major series on the Aquatic Biodiversity of Latin America (ABLA). Their
goal was to find experts who combine the current state of knowledge in taxonomy and
ecology, in order to produce a concise and affordable handbook for each group. About 15
separate monographs, written by reference scientists from various countries will offer a
new, unrivalled view on the aquatic fauna of South America. Information on the ecology
and status of the taxa (written in English) is combined with illustrated identification keys to
families and genera, in both English and Spanish. The series is aimed at zoologists, ecologists,
hydrobiologists, biogeographers, conservationists and students interested in aquatic
biodiversity. The series will be an essential tool for any biological library.
Volume 1: Amazon Fish Parasites (Second edition) by Vernon E. Thatcher.
Pensoft Publishers, Sofia-Moscow, ISBN-10: 954-642-258-4, ISBN-13: 978-954-642-
258-3, 165x240 mm, 508 pp., including 194 plates of figures in line drawings and
photos (16 plates in color); publication date: March 2006.
This book covers the following Phyla and Classes: Protozoa (Myxozoa, Sporozoa),
Plathelminthes (Trematoda, Monogenoidea, Cestoda), Nematoda, Acanthocephala,
Crustacea (Copepoda, Branchiura, Isopoda), Hirudinea and Pentastomida that are known
to parasitize Amazonian fishes. In addition to the keys and checklists, each chapter gives
information on the morphology, life cycles, pathology, prevention, treatment, collection
and methodology, as well as general reference data on each taxon. An alphabetic table of
host fishes with their respective parasites is provided. The book will prove to be useful for
parasitologists, ichthyologists, aquaculturists, pisciculturists and all those interested in
Neotropical fish parasites.
6 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
Author:
PROF. DR. VERNON E. THATCHER
Universidade Federal do Paraná
Faculdade de Ciências Biológicas
Departamento de Zoologia
Caixa Postal 19020
81531-990 Curitiba, Paraná, Brazil
e-mail: thatcher@uol.com.br,
thatcher@ufpr.br
Series Editors:
PROF. DR. JOACHIM ADIS
Max-Planck-Institute for Limnology
Tropical Ecology Working Group
Postfach 165
24302 Plön, Germany
e-mail: adis@mpil-ploen.mpg.de
DR. JORGE R. ARIAS
5870 Colfax Avenue
Alexandria, Virginia 22311, USA
e-mail: jaria2@fairfaxcounty.gov
M.Sc. GUILLERMO RUEDA-DELGADO
Grupo de Investigación en Cuencas y
Humedales Tropicales GICHT
UNIMAG-INTROPIC
Universidad Jorge Tadeo Lozano
Laboratorio de Limnología
Carrera 4 No. 22-61
Bogotá, D.C.
Colombia
e-mail: guillermo.rueda@utadeo.edu.co
ADDRESSES
DR. KARL MATTHIAS WANTZEN
Institute of Limnology
University of Konstanz
Postfach M 659
78457 Konstanz, Germany
e-mail: matthias.wantzen@uni-konstanz.de
Scientific Reader to the Editors:
DR. FRANTIŠEC MORAVEC
Institute of Parasitology
Academy of Sciences of the Czech Republic
Branišovská 31
37005 České Budějovice, Czech Republic
e-mail: moravec@paru.cas.cz
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 7
FOREWORD
Amazon Fish Parasites by Vernon E. Thatcher
It is an honor to provide this introductory statement to the 2nd edition of “Amazon Fish
Parasites” compiled by my dear friend, Dr. Vernon E. Thatcher. Vernon’s contributions to
parasitology span a period of more than five decades, during which time he has published
more than 160 scientific papers, most dealing with the parasites of Neotropical fishes. His
overall contributions include coverage of a wide variety of parasitic taxa, including the
Kinetoplasta (Protista), Digenea, Monogenoidea, Nematoda, Cestoda, Acanthocephala,
Copepoda, Isopoda and Diptera. On one occasion, I remember Vernon commenting that
a “true” parasitologist is one that was knowledgeable, competent, and sufficiently versed
concerning most (if not all) parasitic groups such that he/she could conduct significant
research on any one of them. Vernon has certainly lived up to this definition of a
parasitologist, and it is fitting that he be the person to compile the available information
about the parasites of Amazonian fishes.
Knowledge of the diversity of the parasites of Neotropical fishes, and those of the
Amazon in particular, has significantly increased since publication of the 1st edition of
“Amazon Fish Parasites” in 1991. Much of this new information is due to a large extent
to the more than 60 publications originating from Thatcher’s laboratory since 1991, as
well as works published by other investigators, who undoubtedly were encouraged to
conduct new investigations as a result of the publication of the 1st edition. The new
edition includescoverage of all parasites representing the major parasitic groups infesting
Amazonian fishes listed in the first edition, as well as that of species subsequently reported
in the literature. For each of the major parasitic groups, the 2nd edition includes sections
on Definition and Morphology, Life Cycle and Transmission, Pathology, Prevention and Treatment, as
well as Collection and Methods. These introductory sections are then followed with
identification, keys in English and Spanish, a checklist of species and numerous figures
and references pertaining to the respective groups. The checklist of species not only lists
all species of the taxon reported from the region, but includes diagnoses of families,
subfamilies and genera represented by the species in the list. Finally, the book ends with
a detailed list of hosts and their respective parasites.
Although I am not totally aware of the extensive literature of all parasite groups
represented in the Amazon, coverage of the Monogenoidea (my specialty) suggests that
records presented in the 2nd edition are complete and up-to-date. The organization of
the book and that of each chapter dealing with the individual parasite groups is extremely
conducive for use by other investigators. There is little doubt that the 2nd edition of
“Amazon Fish Parasites” will greatly assist future investigators with identification of
Amazonian fish parasites and provide a convenient means for surveying the literature for
8 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
a variety of studies including taxonomic, phylogenetic and ecologic investigations of the
parasites found in the region. Copies of the 2nd edition of “Amazon Fish Parasites” will
certainly find their way to the book shelves of many libraries and most workers dealing
with the parasites of fishes in the region.
DELANE C. KRITSKY, Ph.D.
Idaho State University
Pocatello, USA
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 9
PREFACE TO THE SECOND EDITION
The first edition of the book, Amazon Fish Parasites, was well received especially in
Europe and tropical American countries. It has proven to be useful to aquarists and
pisciculturists. The book went to press in 1990 and since that time, advances have been
made in several areas of fish parasite research. New genera and species of parasites have
been discovered and described. New finds have been reported in Monogenoidea,
Trematoda, Nematoda, Copepoda and Isopoda and these have been incorporated into the
present edition. Keys in both English and Spanish are provided to aid in the identification
of the parasites. The author hopes that the present edition will continue to be helpful to
those interested in tropical fishes and their parasites and stimulate further studies on these
fascinating animals.
VERNON E. THATCHER
Departamento de Zoologia
Universidade Federal do Paraná
Curitiba, Paraná, Brazil, August 2005
10 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
PREFACE TO THE FIRST EDITION
My first encounter with fish parasites occurred some forty years ago when I took a course
in the subject from the late Dr. Ivan Pratt at Oregon State University. Although I received
only one credit for the course (and had to work very hard for it), I gained a field of
interest that has lasted through the years. Fish parasites are so numerous and varied, and
have adapted to the parasitic way of life in so many ways, that they never cease to
fascinate.
I have had the opportunity to live and work in the American tropics for nearly thirty
years. My studies have frequently involved human and mammalian parasites, but I have
always found time to examine a few fish as well. I have collected and studied fish parasites
from the Grijalva River basin in Tabasco, Mexico, the Chagres River in Panama, the Cauca
River system in Colombia and the Guandu-Aço River in Rio de Janeiro State, Brazil. For
the past twelve years, I have been able to study fish parasites and the pathology they
provoke at the Brazilian National Institute of Amazonian Research (INPA) in Manaus,
Amazonas, Brazil. It has been possible to examine wild caught fish from various parts of
the Amazon region as well as captive fish held in the INPA pisciculture station.
The present book is an attempt to compile all available information on Amazon fish
parasites. For the sake of comparison, freshwater fish parasites from other parts of the
Neotropical Region have been included. Marine species have been omitted, however.
Every effort has been made to produce a work that is as complete as possible. Inevitably,
some references will have been overlooked. Even so, this book should serve as a basic
source of information and stimulate further research in the field.
VERNON E. THATCHER
Manaus, Amazonas, Brazil, February, 1990
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 11
ACKNOWLEDGMENTS
The author is grateful for the continued support of Profs. WOLFGANG J. JUNK and
JOACHIM ADIS of the Tropical Ecology Working Group, Max-Planck-Institute for
Limnology, Plön, Germany. Thanks also to Dr. DELANE C. KRITSKY, Idaho State
University, Pocatello, Idaho (Monogenoidea); Dr. OTTO SEY, University of Agricultural
Science, Keszthely, Hungary and Dr. FRANTIŠEK MORAVEC, Institute of Parasitology,
České Budějovice, Czech Republic, who not only aided in the publication of new species
but also granted permission to reproduce some of the figures used. The author is also
grateful for the collaboration of Dr. WALTER A. BOEGER and R. N. VIANNA, Department
of Zoology, Universidade Federal do Paraná, on the chapter concerning Monogenoidea,
and to Dr. JORGE R. ARIAS, Director of the West Nile Virus Program at the Fairfax
County Health Department, for checking the Spanish translations. Special thanks are due
to Dr. BEDSY DUTARY THATCHER for converting the text of the first edition of the book
to digital format.
VERNON E. THATCHER
Curitiba, Paraná, Brazil, August 2005
12 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
1 INTRODUCTION 19
Cited and general references 22
2 PROTOZOA AND CILIOPHORA
I. Definition and morphology 23
II. Life-cycle and transmission 24
III. Pathology 25
IV. Prevention and treatment 26
V. Collection and study methods 26
VI. Identification and keys 27
Key to the genera of Neotropical Myxosporida 28
Clave para los géneros de Myxosporida Neotropicales 28
Key to Neotropical fish ciliophorans 28
Clave para los cilioforos de peces Neotropicales 29
VII. Checklist of Myxosporida from Neotropical
freshwater fishes 29
Checklist of Ciliophora from Neotropical freshwater fishes 31
VIII. Plates of Protozoa and Ciliophora (Figs. 2–1 to 2–44) 33
IX. Cited and general references 40
3 MONOGENOIDEA
I. Definition and morphology 42
II. Life cycle and transmission 44
III. Pathology 44
IV. Prevention and treatment 45
V. Collection and study methods 45
VI. Identification and keys 50
Key to higher taxa of freshwater Amazonian Monogenoidea 50
Table of Contents
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 13
Key to genera of freshwater Amazonian Gyrodactylidae 51
Key to genera of freshwater Amazonian Dactylogyrinea 51
Clave para las taxas superiores de Monogenoidea
Neotropicales de agua dulce 55
Clave para los géneros de Gyrodactylidae
Neotropicales de agua dulce 55
Clave para los Dactylogyrinea Neotropicales de agua dulce 56
VII. Checklist of Monogenoidea from Amazonian
freshwater fishes and diagnoses 60
VIII. Plates of Monogenoidea (Figs. 3-1 to 3-64) 92
IX. Cited and general references 110
4 TREMATODA (DIGENEA)
I. Definition and morphology 117
II. Life-cycle and transmission 117
III. Pathology 119
IV. Prevention and treatment 120
V. Collection and study methods 121
VI. Identification and keys 122
Key to the Neotropical freshwater fish trematodes 123
Clavepara identificación de Tremátodos, parásitos de
peces Neotropicales 127
VII. Checklist of Trematoda (Digenea) from
Neotropical freshwater fishes 131
VIII. Plates of Trematoda (Digenea) (Figs. 4-1 to 4-99) 154
IX. Cited and general references 203
5 CESTODARIA AND CESTODA
I. Definition and morphology 206
II. Life-cycle and transmission 207
III. Pathology 207
IV. Prevention and treatment 208
V. Collection and study methods 208
VI. Identification and keys 208
14 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
Key to Cestodaria and Cestoda of Neotropical
freshwater fishes 209
Clave para Cestodaria y Cestoda de peces
Neotropicales de agua dulce 211
VII. Checklist of Cotyloda (= Cestodaria) and Eucestoda
(= Cestoda) from Neotropical freshwater fishes 213
VIII. Plates of Cestoda and Cestodaria (Figs. 5-1 to 5-44) 222
IX. Cited and general references 231
6 NEMATODA
I. Definition and morphology 234
II. Life-cycle and transmission 234
III. Pathology 235
IV. Prevention and treatment 236
V. Collection and study methods 236
VI. Identification and keys 237
Key to the superfamilies of Nematoda from Amazonian
freshwater fishes 238
Key to the Ascaridoidea of Amazonian freshwater fishes 238
Key to the Oxyuroidea (Pharyngodonidae) of Amazonian
freshwater fishes 239
Key to the Camallanoidea (Camallanidae) of Amazonian
freshwater fishes 239
Key to the Cosmocercoidea of Amazonian freshwater fishes 240
Key to the Dracunculoidea of Amazonian freshwater fishes 240
Key to the Seuratoidea of Amazonian freshwater fishes 241
Key to the Trichinelloidea (Capillariidae) of Amazonian
freshwater fishes 241
Key to the Gnathostomatoidea (Gnathostomatidae) of
Amazonian freshwater fishes 242
Key to the Thelazioidea (Rhabdochonidae) of Amazonian
freshwater fishes 242
Key to the Physalopteroidea (Physalopteridae) of Amazonian
freshwater fishes 242
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 15
Key to the Habronematoidea of Amazonian freshwater fishes 242
Clave para superfamílias de Nematoda de peces
Amazonicos de agua dulce 242
Clave para las Ascaridoidea de peces Amazonicos de
agua dulce 243
Clave para las Oxyuroidea (Pharyngodonidae) de peces
Amazonicos de agua dulce 244
Clave para las Camallanoidea (Camallanidae) de
peces Amazonicos de agua dulce 244
Clave para las Cosmocercoidea de peces Amazonicos de
agua dulce 245
Clave para las Dracunculoidea de peces Amazonicos de
agua dulce 245
Clave para las Seuratoidea de peces Amazonicos de
agua dulce 246
Clave para las Trichinelloidea (Capillariidae) de
peces Amazonicos de agua dulce 246
Clave para las Gnathostomatoidea (Gnathostomatidae) de
peces Amazonicos de agua dulce 246
Clave para las Thelazioidea (Rhabdochonidae) de peces
Amazonicos de agua dulce 247
Clave para las Physalopteroidea (Physalopteridae) de peces
Amazonicos de agua dulce 247
Clave para las Habronematoidea de peces Amazonicos de
 agua dulce 247
VII. Checklist of Nematoda from Amazonian fishes 248
VIII. Plates of Nematoda (Figs. 6-1 to 6-98) 265
IX. Cited and general references 293
7 ACANTHOCEPHALA
I. Definition and morphology 299
II. Life-cycle and transmission 300
III. Pathology 301
IV. Prevention and treatment 301
16 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
V. Collection and study methods 301
VI. Identification and key 302
Key to Acanthocephala of Neotropical freshwater fishes 302
VI. Identificación y clave 303
Clave de identificación para Acanthocephala de peces
Neotropicales de agua dulce 303
VII. Checklist of Acanthocephala from Neotropical freshwater fishes 305
VIII. Plates of Acanthocephala (Figs. 7-1 to 7-32) 311
IX. Cited and general references 324
8 COPEPODA
I. Definition and morphology 326
Ergasilidae 326
Vaigamidae 328
Lernaeidae 329
Therodamasidae 329
II. Life-cycle and transmission 330
III. Pathology 331
IV. Prevention and treatment 331
V. Collection and study methods 331
VI. Identification and keys 333
Key to Amazonian freshwater ergasiloid females 333
Key to the South American genera and species of
postmetamorphic female Lernaeidae 334
Clave para hembras Ergasiloides dulceacuícolas Amazonicas 335
Claves para los géneros y especies de Lernaeidae
hembras post-metamórficas de América del Sur 336
VII. Checklist of Copepoda from Amazonian freshwater fishes 337
VIII. Plates of Copepoda (Figs. 8-1 to 8-62) 346
IX. Cited and general references 386
9 BRANCHIURA
I. Definition and morphology 390
II. Life-cycle and transmission 390
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 17
III. Pathology 391
IV. Prevention and treatment 391
V. Collection and study methods 391
VI. Identification and keys 392
Key to the Neotropical genera of Branchiura 392
Key to the Neotropical species of Argulus 392
Key to the Neotropical species of Dolops 393
Clave para los géneros Neotropicales de Branchiura 394
Clave para las especies Neotropicales de Argulus 394
Clave para las especies Neotropicales de Dolops 395
VII. Checklist of Branchiura from Neotropical freshwater fishes 397
VIII. Plates of Branchiura (Figs. 9-1 to 9-31) 401
IX. Cited and general references 413
10 ISOPODA
I. Definition and morphology 416
II. Life-cycle and transmission 416
III. Pathology 417
IV. Prevention and treatment 419
V. Collection and study methods 419
VI. Identification and keys 419
Key to the Genera of Cymothoidae from Neotropical
freshwater fishes 420
Clave para los géneros de Cymothoidae de peces
Neotropicales de agua dulce 421
VII. Checklist of Isopods from Neotropical freshwater fishes 422
VIII. Plates of Isopoda (Figs. 10-1 to 10-62) 427
IX. Cited and general references 451
11 HIRUDINEA, PENTASTOMIDA AND OTHER PATHOGENS
HIRUDINEA 454
I. Definition and morphology 454
II. Life-cycle and transmission 455
III. Pathology 455
18 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
IV. Prevention and treatment 455
V. Collection and study methods 455
VI. Identification and key 456
Key to leeches from Neotropical freshwater fishes 456
Clave para Sanguijuelas de peces Neotropicales de agua dulce 456
VII. Checklist of Hirudinea from Neotropical fishes 456
PENTASTOMIDA 458
I. Definition and morphology 458
II. Life-cycle and transmission 458
III. Pathology 458
IV. Prevention and treatment 458
V. Collection and study methods 459
VI. Identification 459
VII. Checklist for Pentastomida 459
Other pathogens 460
VIII. Plates of Hirudinea and miscellaneous
pathological conditions (Figs. 11-1 to 11-7) 461
IX. Cited and general references 464
12 ADDENDUM: HOST–PARASITE TABLE 465
13 SUBJECT INDEX 497
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 19
1
INTRODUCTION
Fish parasitology and pathology are fields of growing importance in view of a worldwide
expansion of pisciculture efforts. It would seem to be inevitable that world populations
will come to depend more and more on artificially cultured fish as naturally occurring fish
populations become depleted. Fish parasitology and pathology are not really separate
areas of study since most fish parasites cause mild to severe pathological alterations in
their hosts. Although it would be possible to study fish parasites and disregard the
pathology they produce, it would not be feasible to delve into fish pathology (ichthyopa-
thology) while ignoring the parasites that cause most of the damage.
Although no universally applicable definition of parasitism has ever been devised,
for our purposes we can consider a parasite as an animal that lives on or in an animal of a
different species (host) at the expense of the latter. The host pays the bill by providing
sustenance to the parasite. During the evolution of such a relationship over long time
periods, the parasite gradually loses its abilityto elaborate certain molecules that are
essential to its own metabolic well being. The true parasite therefore has a physiological
dependence on a particular host species and cannot survive without the association.
Ultimately then, parasitism would have to be defined in terms of the biochemical
dependency of the parasite on the host. Even though details of these associations at the
biochemical level are incomplete or lacking, we can surmise a great deal from differences
in degrees of host specificity. As it turns out, most parasites are host specific and some
can develop only on a single host species. Others are limited to host species of a single
genus while some can grow on host genera of only one family group. Even those parasites
that occur on a variety of hosts are usually found to have preferences. Parasites on the
preferred host generally are found in greater numbers, have individuals of larger size and
produce more eggs or larvae per parasite.
Pathology is literally the study of “pathos”. Pathos means suffering, especially that
brought on by disease, physical injury or nutritional deficiencies. Pathology is also the
resultant damage produced in an organism by these conditions. Ichthyopathology differs
considerably from human or mammalian pathology for several important reasons. For
one thing, we cannot ask a fish where it hurts so we have to depend on visible indications
such as alterations in cells and tissue (histopathology) and the presence and identification
of invading disease organisms. Also, the aquatic environment is very different from the
terrestrial one in terms of disease transmission. The human pathologist spends much time
diagnosing and characterizing diseases caused by microorganisms (viruses, bacteria and
fungi), those of a hereditary nature and those associated with ageing. He is little
20 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
concerned with parasites, at least in Northern temperate climes. The ichthyopathologist,
on the other hand, is more involved with parasitic and nutritional disorders. Microbial and
hereditary diseases have been little studied in Neotropical fish and sick animals are usually
removed from the environment by predators before they grow very old.
The following major groups of animal parasites invade Neotropical freshwater
fishes: Protozoa, Myxozoa (= Myxosporida), Ciliophora, Platyhelminthes (Monogenoidea,
Trematoda (Digenea), Cestodaria, Cestoda), Nematoda, Acanthocephala, Arthropoda
(Copepoda, Branchiura, Isopoda), Annelida (Hirudinea) and Pentastomida. The groups
listed here represent 14 Classes or Orders of eight or nine animal Phyla. Of the 14
groups, only five infect man and only seven invade other mammals.
All of these parasitic forms evolved from free-living, frequently predatory, ancestors.
With the exception of Myxosporida, Acanthocephala and Pentastomida, the free-living
relatives are still around and can be found in nearly any body of water. All of these
invertebrate animal groups had already evolved before the first vertebrates appeared on
the scene. First to show up were the fishes and they offered numerous new niches for the
invertebrate groups to exploit. Fish therefore have a greater quantity and variety of
parasites than any other class of vertebrates because they have lived for a longer time
period in close association with the greatest variety of invertebrate forms. Parasitism, as
such, did not arise as a result of the appearance of the first vertebrates, however. Small
invertebrates had long been invading larger ones and many of these were therefore pre-
adapted to parasitize vertebrates when the opportunity arose.
Parasites are usually divided into ecto and endoparasites depending on whether they
live on the surface or within their hosts. In the case of fish ectoparasites, they may live on
the external surface, within the mouth or on the gills. All other habitats within the fish are
considered to be interior. To these general categories a third should be added, namely,
blood and tissue parasites. For a parasite to penetrate the circulatory system or tissues of
a host represents an evolutionary advance and these sites must be considered more
“interior” than the lumen of the digestive tract and associated organs.
One of the first requisites of the successful parasite is its ability to remain in position
on or within its host and not be swept away by the current. This is particularly evident in the
case of ectoparasites living on the slippery skin of fast swimming fish. As every fisherman
knows, one good way to catch a fish is with a fishhook. Parasitic crustaceans (Copepoda,
Branchiura and Isopoda) have evolved claws that closely resemble fishhooks and some even
have barbed points. Other attachment devices found among fish parasites include entangling
threads, suckers, spines, clamps, tentacles and clasping or latching appendages.
Much of the histopathology observed in fish is a direct result of the physical damage
done to the tissues by the attachment devices of the parasites. Such damage includes
localized hemorrhaging, cellular enlargement (hypertrophy), increased cellular growth
(hyperplasia) and the transformation of epithelial cells to mucous cells (metaplasia).
Parasites can also damage host tissues by their physical presence (causing pressure
atrophy), by chemical secretions or excretions and by their mode of feeding. For example,
some monogenean worms individually cause little harm to the gills of their hosts, but
sometimes they are present in such large numbers that they impede the breathing function of
the lamellar surfaces. Other monogenean species actively feed on epithelial and blood cells, and
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 21
can destroy the gill lamellae and filaments (Fig. 3-63). Still others provoke tumoroid growths
near the site of attachment presumably by chemical excretions (Fig. 3–64).
Sick or parasitized fish can frequently be recognized as such by the observant
pisciculturist or aquarist because their behavior alters. Signs to watch for include: color
changes, failure to keep up with others in a school, erratic or circular swimming patterns,
alterations in swimming posture (i.e. head, tail or belly frequently uppermost) and surface
gasping. The latter often indicates a low level of dissolved oxygen in the water, but it can
also signal the presence of excessive numbers of gill parasites.
Treatment of parasitized fish can sometimes be accomplished but is not without its
inherent difficulties. Chemical medications can be mixed with pellet-type ration and
offered to the fish, but if they are already sick, they may not be eating. This method works
better as a control to prevent the build-up of excessive numbers of parasites in relatively
healthy fish. The most common technique for treating fish is the chemical “dip” where
the fish are removed from their tanks and placed in chemically altered water for a short
time, and then returned to their previous environment. This method can be quite
successful, especially against ectoparasites. It should be remembered, however, that
catching and transferring the fish introduces the element of stress which can be fatal to
animals that are already sick. Anti-parasite chemicals can also be introduced directly into
the stomach by tube, or injected into the muscles or circulatory systems by hypodermic
syringe. These methods work admirably at times, but again the factor of stress must be
taken into consideration. If, for example, we took a chicken and held it under water for
several minutes while administering some painful treatment, the stress would be
comparable to that of a fish taken from water.
Since the treatment of fish is admittedly difficult, it would be far better if we could
keep them from getting infected in the first place. In order to be able to do so, we shouldhave detailed information concerning parasite life-cycles, especially as regards their
transmission from one host to another. Unfortunately, few studies have been made on
parasite life-cycles in the Neotropics. In many cases, however, we can deduce the mode of
transmission from studies done on similar parasites elsewhere. Some parasitic organisms
invade fish by direct means. That is, as active larvae or adults they swim up to a fish and
attach or penetrate. Ciliophora, Copepoda, Branchiura, Isopoda and Hirudinea use this
approach. Others have larval forms that are eaten by the fish, sometimes within
intermediate hosts or attached to aquatic vegetation. Trematoda, Cestoda, Nematoda and
Acanthocephala gain entry into fish in this way. Specific suggestions for ways to break the
transmission cycles are to be found in the chapters that follow.
Original papers on Neotropical fish parasites are scattered through the scientific
journals of six countries and were published in five different languages. Until the first
edition of this book, no general reference work about these parasites had been available.
The existing books on fish parasites and pathology, such as: HOFFMAN (1967, 1999); KINNE
(1984); REICHENBACH-KLINKE & LANDOLT (1973); RIBELIN & MIGAKI (1975); and ROBERTS
(1978), provide useful information based on North American and European forms, but
they are of little help in identifying Neotropical species.
Each of the following chapters of this work deals with a major group of Neotropical
fish parasites. It will be noted that Chapter 3, Monogenoidea and Chapter 8, Copepoda are
22 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
longer than the others. This reflects a reality in that these parasites are more numerous and
varied on these fish than any of the others. They are also the forms that cause the most
problems for pisciculturists and aquarists. Each chapter contains the following topics:
I. Definition and morphology; II. Life-cycle and transmission; III. Pathology; IV.
Prevention and treatment; V. Collection and study methods; VI. Identification and keys
(English and Spanish); VII. Checklist of species; VIII. Figures and IX. References. The
keys facilitate identification to genus. After the genus of a parasite is determined, the
checklist should be consulted to find out what species is represented. The checklists are
arranged alphabetically and after each specific name, the host, country where found,
figure citation and measurements are given. If the user wishes to find out what other
parasites have been reported from the same host, he may consult the addendum, which is
a host-parasite table.
Cited and general references
HERWIG, N. (1979): Handbook of drugs and chemicals used in the treatment of fish diseases. -
Charles C. Thomas Publ., Springfield: 272 pp.
HOFFMAN, G. L. (1967): Parasites of North American freshwater fishes. - Univ. Calif. Press,
Berkeley: 486 pp.
HOFFMAN, G. L. (1999): Parasites of North American freshwater fishes. - 2nd. ed., Cornell Univ.
Press, Ithaca: 539 pp.
KINNE, O. (ed.) (1984): Disease of marine animals. Vol. 4, Part 1. Introduction, Pisces. - Biologische
Anstalt Helgoland, Hamburg: i–xv, 541 pp.
OLSEN, O. W. (1974): Animal parasites, their life cycles and ecology. - Univ. Park Press, Baltimore:
562 pp.
REICHENBACH-KLINKE, H. H. & M. LANDOLT (1973): Fish pathology. - TFH Press, Neptune City:
512 pp.
RIBELIN, W. E. & G. MIGAKI (eds.) (1975): The pathology of fishes. - Univ. Wisconsin Press,
Madison: 1004 pp.
ROBERTS, R.J. (ed.) (1978): Fish pathology. - Bailliere Tindall, London: 318 pp.
THATCHER, V. E. & J. BRITES NETO (1991): Diagnóstico, prevenção e tratamento das enfermidades
de peixes Neotropicais de água doce. - In: VAL, A. L., FLIGLIUOLO, R. & E. FELDBERG (eds.):
Bases científicas para estratégias de preservação e desenvolvimento da Amazônia: 339–371.
Fatos e perspectivas. Impressa CNPq INPA/UA, Manaus: 440 pp.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 23
2
PROTOZOA AND CILIOPHORA
I. Definition and morphology
The Phylum Protozoa formerly included all small unicellular animals, but in recent
years there has been a tendency to regard some of the component groups as separate
phyla. After all, a Paramecium and a malaria parasite have little in common in terms of
either morphology or life-cycle. Representatives of the protozoan groups Mastigo-
phora, Myxosporida, Coccidida, and some genera of the Phylum Ciliophora (formerly
Class Ciliata) have been reported from Neotropical freshwater fishes and these forms
will be treated here.
Trypanosoma spp. are the only mastigophorans known from Neotropical freshwater
fishes. Species of this genus have a single flagellum arising from a posterior blepharoplast
which is fused along the length of the body to form an undulating membrane. Beyond the
front end, the same flagellum is free and whip-like. The body tapers towards both
extremities and the nucleus is usually near the middle or in the anterior half (Fig. 2–35).
Trypanosomes are found in the blood of their hosts.
The myxosporidans, especially species of the genera Myxobolus and Henneguya, are
among the most common and conspicuous of fish parasites. These invaders form spore
filled cysts in the host tissues that vary in size from less than one millimeter to more than
one centimeter. Such cysts are found in and on the gills, under the skin and within internal
organs, such as muscles, liver, spleen and intestinal wall. Subcutaneous cysts sometimes
cause such deformations in fish that they can be observed in nature (Figs. 2-40 & 41).
Small cysts, when numerous, give an organ like the liver a granular or white spotted
appearance. Identification of myxosporidan cysts is made by opening them with dissecting
needles and examining the contents under a microscope at 400x magnification. Myxospori-
dan cysts contain large numbers of vegetative (non-motile) spores composed of two shell-
like valves. Within each spore, from one to four cylindrical polar capsules may be seen and
each of these contains a spiral filament. From one to five nuclei may also be visible.
Coccidia are usually found in the intestinal wall, or in associated organs such as the
liver. Identification of Calyptospora sp. (Eimeriidae), the only coccidian presently known to
occur in Neotropical fishes, can be made under 400x magnification by finding oocysts
containing four spores, each of which has two sporozoites (Figs. 2-28 & 2-44 A-B).
Fish ciliophorans are usually found on the skin or gills, or within the intestinal
contents of their hosts. These animals are easily recognized at 100x magnification by the
24 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
presence of motile cilia which cover the external surfaces (Figs. 2-29 to 2-34). In living
specimens, it is often possible to see the large macronucleus. In stained preparations, a
smaller micronucleus near to, or attached to, the macronucleus may be discerned.
II. Life-cycle and transmission
Trypanosomes have been described from several siluriform fishes and a few characins from
Brazil, but their life-cycles have not been studied. We can presume, however, that they must
have a leech (Hirudinea) as intermediate host and vector as do the North American species.
Transmission to an uninfected fish is therefore by way of the bite of an infected leech.
Transmission of myxosporidans from one host to another is by means of the
bivalved spores. When these spores are ingested by the specific host fish, the polar
capsules discharge the filaments to entangle in the cells of the gut wall and this serves to
anchor the spore. After anchoring, the valves open and a single ameboid parasite (sporont)
leaves the spore and penetrates the intestinal wall. The sporont is carried throughout the
body in the circulatory system until the proper organ is reached.Myxosporidan species are
apparently quite specific both in host and site selection. After settling at the site, the
sporont (trophozoite) begins to produce numerous new spores internally by asexual
nuclear divisions (for details on sporozoan life-cycles; see HOFFMAN, 1999).
Although myxosporidan life-cycles would appear to involve only one host, there is
some evidence to suggest that at least some species need two animals. According to WOLF
(1982), the spores of Myxosoma (or Myxobolus) cerebralis must “age” for three months or so
before they become infective. The same author found that oligochaete worms, especially
those of the genus Tubifex, ingested the spores and became infective to experimental trout.
Some myxosporidans alter the behavior of their host fishes to the extent that they
fall easy prey to predators. This suggests that piscivorous animals may be important in
disseminating the spores and it may be that passage through the digestive system of
another animal changes the capsules and makes the spores infective. In the Cauca River
valley of Colombia, entire populations of Astyanax fasciatus periodically become
infected with a species of Henneguya. The parasites form large cysts under the skin, in
the musculature and their swimming ability is impaired. Heavily infected fish swim near
the surface in a slow and disoriented manner. Such fish are easy for piscivorous birds to
catch and it is evident that the spores could be rapidly dispersed to other ponds in the
bird feces. Piscivorous fish, reptiles and mammals could also spread the spores, but to a
more limited extent. Personal field observations indicate that this species of Henneguya
acts as a control on populations of A. fasciatus. The parasite spores can only escape from
the fish after its death so by incapacitating its host, the parasite is aiding in the
completion of its cycle and in its own dispersal. This is an exception to the rule that a
parasite does not harm its host. TAYLOR (1978) showed experimentally that whirling
disease in trout, caused by Myxosoma cerebralis, a myxosporidan which invades the
nervous system, could be transmitted in bird feces.
In our studies of Amazonian fishes, we have frequently encountered a coccidian
(Eimeriidae) in the livers of Triportheus elongatus. Although life-cycle studies of this species
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 25
have not been done, it seems probable that an intermediate host would be required. In this
case, the species would belong to the genus Calyptospora OVERSTREET, HAWKINS & FOURNIE,
1984. It may be that freshwater shrimp, Macrobrachium spp., are intermediate hosts for this
parasite and transmission occurs when fish eat infected shrimp.
Intestinal ciliophorans enter the fish by way of food and detritus eaten by the
host. Most of these small invaders are probably harmless commensals and they are
common in fish that ingest bottom detritus, such as the loricariid catfish. The case of
Ichthyophthirius multifiliis is quite different since these animals actively seek out a fish
host and invade the epithelium of its skin and gills. This parasite is not limited to the
Neotropics, but has become a pest of aquarium fishes the world over. There is a body
of evidence to suggest that “Ich” is more of a symptom than a disease. It may be that
this ciliophoran only invades fish that are already stressed by overcrowding, inade-
quate nutrition or poor water quality. In our study of wild-caught Amazon River
fishes, we have never been able to detect the presence of I. multifiliis. Cauca River fish,
in Colombia, only became infected with “Ich” after being maintained in aquaria for
several months.
While on a fish host, I. multifiliis grows from a size of less than 50 microns to nearly
one millimeter. After this, it drops off of the fish, settles to the bottom and encloses itself
in a protective capsule (cyst). Within the capsule, divisions occur which result in the
production of several hundreds of oval, ciliated tomites, each about 2-30 microns long.
The capsule eventually ruptures freeing the tomites to seek new hosts.
III. Pathology
Trypanosomes in man and other mammals cause a severe disease and they can invade and
weaken the heart musculature. We do not know if trypanosomes in Neotropical fishes
cause similar problems since detailed studies of these parasites within the tissues of the
hosts have not been made.
As noted above, Myxosporida and Coccidida cause the deformation of fish and
alter their behavior. The invasion of these parasites does not provoke an inflammato-
ry reaction on the part of the normal host so the cysts are able to grow continuously,
taking up the space of host cells, until the death of the fish becomes inevitable. An
infection known as “whirling disease” is a serious problem in Northern trout
hatcheries. This disease gets its name from the circular swimming behavior of
infected fish, which is caused by the invasion of the central nervous system by a
myxosporidan (Myxosoma cerebralis). The only cerebral myxosporidan known in
Neotropical fishes, is Myxobolus inaequus KENT & HOFFMAN, 1984, but it is not known
if this parasite modifies host behavior.
Intestinal ciliophorans, such as Balantidum and Nyctotherus, do not produce any
notable pathology. Ichthyophthirius multifiliis, on the other hand, causes skin lesions that are
easy to recognize. Infected areas are of a grey or whitish appearance and they have
irregular margins. Examination with a dissecting microscope, or a hand lens, will reveal the
presence of spherical trophozoites, typically in slow rotation.
26 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
IV. Prevention and treatment
No treatment is required for intestinal ciliophorans and the blood inhabiting trypano-
somes since these organisms have not been shown to be pathogenic. Eliminating leeches
from the aquaria breaks the transmission cycle of trypanosomes and prevents the
contamination of uninfected fish.
Prevention of Myxosporida and Coccidida is made more difficult by the fact
that the life-cycles are little understood. Infected fish showing obvious tumors
should be removed from the aquarium, or pond, and incinerated to limit further
dissemination of the organisms. Surviving fish should be placed in a clean aquarium
which is free of small invertebrate animals, such as Tubifex. As a treatment for
Coccidida, Monesin (Eli Lilly Co.) is routinely used in chickens and has been
reported to give good results against a fish coccidian (SOLANGI & OVERSTREET
1980). The drug may be injected or mixed with food, however, dosages would have
to be determined for particular host-parasite systems. This drug would probably be
useful against myxosporidan infections as well.
Prevention of Ichthyophthirius multifiliis and other skin invaders, involves care in
maintaining good water quality and good nutrition. At the first sign of the disease,
the fish should be removed to clean aquaria, separating the infected fish from the
uninfected ones. Sick fish should be treated by chemical dip, such as Malachite
green at 1:15,000 parts for 10-30 seconds or Formalin at 1:4,000 for 10-30 minutes.
Either of these treatments should be repeated on three consecutive days and then
the fish should be kept in a clean aquarium for one week of observation to see if
additional treatment is needed.
V. Collection and study methods
For trypanosomes, fresh blood smears are made on slides, allowed to air dry, fixed in
absolute methanol and stained in either Giemsa or Wright’s stain. The parasites should be
studied under oil immersion at 1,000x magnification.
Myxosporidan cysts in fish tissues are white and can frequently be seen with the
naked eye. The cysts can be excised, fixed in AFA (85 parts 85 % alcohol, 10 parts of
commercial formaldehyde and five parts glacial acetic acid), or in 10 % formalinsolution,
and stored in glycerinated alcohol (90 parts of 80 % alcohol to 10 parts of glycerin).
Spores may be removed from the cysts with dissecting needles, partially dehydrated in 95
% alcohol and cleared in pure phenol for identification and study.
Ciliophorans are best studied alive, and vital stains, such as neutral red, can be used
to better visualize the nuclei. If permanent preparations are desired, the animals should be
killed by immersion in hot AFA, and after fixation in this solution for at least 5 minutes,
the slides may be made by the following procedure:
1) Place the material containing ciliophorans in a tapered centrifuge tube and spin at
low speed for 30 seconds.
2) Decant the AFA, replace with water, stir and centrifuge for 30 seconds.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 27
3) Decant the water, replace with water containing one drop of Mayer’s carmalum
stain and stir.
4) Leave material in this stain solution for 5 minutes, then centrifuge for 30 seconds.
5) Decant the stain solution, replace with 50 % alcohol, stir and spin for 30 seconds.
6) Dehydrate by sequentially passing material in same tube through 70, 85, 95, 100 %
alcohol, xylol and half xylol-half balsam (spin for 30 seconds between each solution).
7) Sample of material can be removed from the xylol-balsam with a thin pipette and
mounted in balsam on microscope slides.
VI. Identification and keys
Blood inhabiting mastigophorans are easily identified as the genus Trypanosoma (Fig. 2-35).
Characters used to separate species are: body shape and size; position and size of the
blepharoplast and nucleus; length of the free part of the flagellum; and host identity.
Unfortunately, these parasites are extremely variable. There may be more than one
morphological type within a single species, and it is also possible for more than one
species to occur in the same host. Existing names for trypanosome species from
Neotropical fish are of doubtful validity since they are mainly based on host identity. Only
after these parasites have been studied by electron microscopy, artificial medium culturing
and physiological techniques will we know how many species are involved and which
names are valid. In Brazil, nominal species have been proposed as follows:
TRYPANOSOMA HOST FISH
albopunctatus Hypostomus albopunctatus
chaetostomi * Chaetostomus sp.
chagasi Hypostomus punctatus
dorbignyi Rhinodoras dorbigny
ferreirae * Characinidae
francirochai * Otocinclus francirochai
guaibensis Hypostomus commersoni
hypostomi Hypostomus aurogutatus
iheringi Franciscodoras marmoratus
immanis Loricariichthys anus
larai *Prochilodus sp.
loricariae Loricaria sp.
macrodontis * Hoplias malabaricus
margaririferi Hypostomus margaritifer
paivae * Characinidae
piracicabae Loricaria piracicabae
plecostomi Hypostomus sp.
regani Hypostomus regani
rhamdiae Rhamdia quelen and R. sapo
splendorei Rhamdia sapo
28 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
strigaticeps Hypostomus strigaticeps
zungaro Pseudopimelodus zungaro
(Hosts marked with an asterisk are characins and all others are catfish, Siluriformes).
Important considerations in the identifications of Myxosporida are: size and form of
the spore; number, position and size of the polar capsules; host identity; and site within
the host. The following key is offered as an aid in determining genera. Known species may
be identified by recourse to the figures and to the measurements in the checklist. All
measurements are given in micrometers (µm).
Key to the genera of Neotropical Myxosporida
I. Polar capsules located in one extremity of the spore only.
A. Spore capsule provided with 1-3 tail-like extensions.
1. Four polar capsules present ....................................................... Agarella (Fig. 2–16)
2. Two polar capsules present .................................... Henneguya (Figs. 2–17 to 2–24)
B. Spore capsule without tail-like extensions .................. Myxobolus (Figs. 2–1 to 2–15)
II. Polar capsules located in opposite extremities ...................... Myxidium (Figs. 2–25 to 2–27)
Clave para los géneros de Myxosporida Neotropicales
I. Cápsulas polares localizadas en solo una de las extremidades de la espora.
A. Cápsula de la espora provista de 1-3 extensiones en forma de cola.
1. Cuatro cápsulas polares presentes ............................................ Agarella (Fig. 2–16)
2. Dos cápsulas polares presentes ................................ Henneguya (Figs. 2–17 a 2-24)
B. Cápsula de la espora sin extensiones en forma de cola ................................................
................................................................................................ Myxobolus (Figs. 2–1 a 2–15)
II. Cápsulas polares localizadas en extremos opuestos ........ Myxidium (Figs. 2–25 a 2–27)
Key to Neotropical fish ciliophorans
Fish ciliophorans can be identified by: size and form of the body; shape of the
macronucleus; and nature of the cytostome.
I. Macronucleus horseshoe-shaped.
A. Body spherical, striate .............................................. Ichthyophthirius multifilis (Fig. 2–31)
B. Body bell-shaped, with oral denticles ............... Trichodina fariai (Figs. 2–32 & 2–34)
II. Macronucleus bean-shaped.
A. Body rounded ...................................................................Balantidium piscicola (Fig. 2–29)
B. Body elongate .........................................................Rhynchodinium paradoxum (Fig. 2–33)
III. Macronucleus triangular ........................................................Nyctotherus piscicola (Fig. 2–30)
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 29
Clave para los cilioforos de peces Neotropicales
Los cilioforos de peces pueden ser identificados por: tamaño y forma del cuerpo; forma
del macronúcleo; y naturaleza del citostoma.
I. Macronúcleo en forma herradura.
A. Cuerpo esférico, estriado ........................................ Ichthyophthirius multifilis (Fig. 2–31)
B. Cuerpo en forma de campana con dentículos orales ....................................................
................................................................................... Trichodina fariai (Figs. 2–32 & 2–34)
II. Macronúcleo en forma de frijol.
A. Cuerpo arredondeado .....................................................Balantidium piscicola (Fig. 2–29)
B. Cuerpo alargado .....................................................Rhynchodinium paradoxum (Fig. 2–33)
III. Macronúcleo triangular .........................................................Nyctotherus piscicola (Fig. 2–30)
VII. Checklist of Myxosporida from Neotropical freshwater fishes
Measurements are given in micrometers (µm).
Myxosporida
Myxozoa. Unicellular parasites. Trophozoite amoeboid, but without pseudopodia;
resistant infective spores form within trophozoite. Tissue parasites of fishes, rarely
amphibians.
Agarella DUNKERLY, 1915.
Spore elongate; of two valves having tail-like extensions; four polar capsules
present, two of which are smaller. Tissue parasites of freshwater fish.
A. gracilis DUNKERLY, 1915: testes of Lepidosiren paradoxa: Brazil. (Fig. 2–16).
Spore = 16 x 4; tail = 14.
Henneguya THÉLOHAN, 1892. Spore elongate; of two valves having tail-like
extensions; two polar capsules present. Tissue parasites of freshwater fish.
H. iheringi PINTO, 1928: gill filaments of Serrasalmus spilopleurus: Brazil. (Fig. 2–
17). Spore = 22 x 6; polar capsules = 3.4 x 2.
H. leporini NEMECZEK, 1926: urinary bladder of Leporinus mormyrops: Brazil.
(Fig. 2–18). Spores = 13–15 x 5; tail = 15–18; polar capsule = 5–8.
H. linearis (GURLEY, 1893) LABBÉ, 1899: peritoneum of Rhamdia sebae and Pseudo-
platystoma fasciatum: Brazil. (Fig. 2–21). Spore = 3 x 4 times longer than wide.
H. lutzi CUNHA & FONSECA, 1918: gall bladder of Pseudopimeloduszungaro: Brazil.
(Fig. 2–19). Spore = 11 x 7; tail = 22.
H. malabarica AZEVEDO & MATOS, 1996: gill filaments Hoplias malabaricus: Pará
State, Brazil. Spore = 26.6-29.8.
H. oculta NEMECZEK, 1916: gills of Loricaria sp.: Brazil. (Fig. 2–22). (Measure-
ments unavailable).
H. schizodon EIRAS, MALTA, VARELLA & PAVANELLI, 2004: kidney of Schizodon
fasciatus: Amazon River, Manaus, Brazil. Spore = 12–13 x 3–4; caudal
process = 15–17.
30 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
H. theca KENT & HOFFMAN, 1984: brain of Eigenmannia virescens: Brazil. Spore
= 40.6–52.6 x 3.0–4.1.
H. wenyoni PINTO, 1928: gills of Astyanax fasciatus: Brazil. (Fig. 2–20). Spore =
11–12 X 4.5–6.0; tail = 8–12; polar capsule = 1.5.
Myxidium BÜTSCHLI, 1882. Spores elongate, with one polar capsule at each
extremity. Tissues of fishes, rarely of amphibian and aquatic reptiles.
M.cruzi PENIDO, 1927: bile duct of Chalcinus nematurus: Brazil. (Fig. 2-25).
Spores = 17-18 x 5-7; polar capsules = 5-6 x 2-3.
M.fonsecai PENIDO, 1927: gallbladder of Carapus fasciatus: Brazil. (Fig. 2-26).
Spores = 7-9 x 2.5-3; polar capsules = 2-3.
M.gurgeli PINTO, 1928: bile duct Acestrorhamphus sp.: Brazil. (Fig. 2-27). Spores
= 14.6 x 8.5-3; polar capsules = 3.4 x 3.
Myxobolus BÜTSCHLI, 1882. Spores oval or pyriform, with two polar capsules in
one extremity; valves without tail-like extensions. Tissues of fishes and
rarely amphibians.
M.associatus NEMECZEK, 1926: kidney of Leporinus mormyrops: Brazil. (Fig. 2-1).
Spore = 15 x 10; polar capsule = 7.
M.braziliensis CASAL, MATOS & AZEVEDO, 1996: gills of Bunocephalus coracoideus:
Amazon River, Pará State, Brazil. Spore = 9.5-11 x 4.7-6.
M.cunhai PENIDO, 1927: intestine of Serrasalmus piraya and Pimelodus clarias:
Brazil. (Fig. 2-2). Spore = 9-11 x 4-6.
M.galaxii SZIDAT, 1953: gills of Galaxias maculatus: Argentina. (Fig. 2-4). Spore
= 14-15 x 9-10.
M.inaequalis GURLEY, 1893: skin of Pimelodus clarias: Brazil. (Fig. 2-3). Spore =
5.2-3.3.
M.inaequus KENT & HOFFMAN, 1984: brain of Eigenmannia virescens: Brazil.
Spore = 15.6-22 x 7.8-9.3.
M.kudoi GUIMARÂES & BERGAMIN, 1938: skin of unidentified fish: Brazil. (Fig.
2-5). Spore = 8.8-8.9 x 6.5-7.3; capsules = 3.5-4.2 x 1.3-2.0.
M.lutzi ARAGÂO, 1919: testis of Poecilia vivipara: Brazil. (Fig. 2-6). Spore = 10 x 7.
M. magellanicus SZIDAT, 1953: gills of Galaxius maculatus: Argentina. (Fig. 2-
7). Spore = 10-13 x 8-9; polar capsules = 3.
M.noguchii PINTO, 1928: gills of Serrasalmus spilopleurus: Brazil. (Fig. 2-8). Spore
= 13.6 x 8.5; polar capsules = 6.8-2.2.
M.pygocentris PENIDO, 1927: intestine of Serrasalmus piraya: Brazil. (Fig. 2-9).
Spore = 15-16 x 9-11; polar capsules = 9-11 x 3-4.
M.serrasalmi WALLIKER, 1969: spleen, kidney & liver of Serrasalmus rhombeus:
Brazil. (Fig. 2-10 A-B). Macrospore = 12-18 x 7-10; polar capsules = 6-9 x
2-4; microspore = 7.0-9.5 x 3.5-5; polar capsules = 5-7 x 1.2.
M.stokesi PINTO, 1928: skin of Pimelodus sp.: Brazil. (Fig. 2-11). Spore = 8.5 x 5.3.
Myxobolus sp. SZIDAT, 1953: skin of Pimelodus albicans: Argentina. (Fig. 2-12).
Spore = 15 x 8.
Myxobolus sp. WALLIKER, 1969: spleen and liver of Colossoma bidens: Brazil. (Fig.
2-14). Spore = 8-10 x 4-7; polar capsules = 3.5-5.0 x 1.0-2.5.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 31
Myxobolus sp. WALLIKER, 1969: kidney of Serrasalmus sp.: Brazil. Spore = 9 x 11
x 5-6.5; polar capsules = 5-6 x 1.5-2.0.
Checklist of Ciliophora from Neotropical freshwater fishes
Measurements are given in micrometers (µm).
Phylum Ciliophora.
Unicellular animals possessing cilia or structures composed of cilia in
some stage of the life-cycle. Basal granules for coordinating ciliary motion
also present. Cystostome (mouth), macronucleus and micronucleus usually
present. Reproduction by binary fission and conjugation. Free-living and
parasitic.
Balantidium CLAPARÈDE & LACHMAN, 1858. Trophozoite oval or elliptical. Cytostome
near anterior extremity; cytopharynx not well developed. Body ciliation
uniform. Cytopyge and contractile vacuole terminal. Intestine of inverte-
brates and vertebrates.
B. piscicola GÈZA, 1913: gut of Piaractus brachypoma and Pimelodus clarias: Brazil.
(Fig. 2-29). Body = 36 x 28; macronucleus = 12 x 6-7; cilia = 3-4.
Nyctotherus LEIDY, 1877. Body oval, compressed; cytostome in midbody; cytopharynx
long, with undulating membrane. Macronucleus large, triangular, anterior.
Cytopyge and contractile vacuole terminal. Gut of invertebrates, fish and
mammals.
N. dilleri EARL & JIMÉNEZ, 1969: Cichlasoma fenestratum: México. Body = 154-
280 x 80-140; macronucleus = 6-10 x 12-30.
N. piscicola DADAY, 1905: Colossoma brachipomum, Pimelodus clarias and Acestrorham-
pus sp.: Brazil. (Fig. 2-30). Body = 112-153; macronucleus = 12-30 x 30-90.
Rhynchodinium CUNHA & PENIDO, 1927. Body elongate, cylindrical, tapering anteriorly;
cilia long, lacking posteriorly. Macronucleus ovoid, anterior in position.
Cytopyge and contractile vacuole terminal. Intestine of fish.
R. paradoxum CUNHA & PENIDO, 1927: Pterodoras granulosus: Brazil. (Fig. 2-33).
Body = 20-30 x 5-10.
Trichodina EHRENBERG, 1834. Body cup or bell-shaped, with three circular rows of
cilia; oral surface provided with chitinized ring and circle of denticles.
Macronucleus U-shaped. On skin of marine and freshwater crusta-
ceans and fish.
T. fariai CUNHA & PINTO, 1928. Sphaeroides testudineus: Brazil. (Figs. 2-32 & 2-
34). Body = 32 x 20-22; with 24-28 denticles.
Sporozoa
Calyptospora OVERSTREET, HAWKINS & FOURNIE, 1984. Sporocyst covered with a thin
veil supported by one or more sporopodia; lacking Stieda body; with
membrane covered oblong opening. Suture extending a short distance
distally on opposite sides then converting to low ridges that continue to
32 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
posterior end. Sporozoite developing in invertebrate host. Parasites of
marine and freshwater fishes.
C. tucunarensis BÉKÉSI & MOLNÁR, 1991: liver of Cichla ocellaris: Ceará State,
Brazil. (Figs. 2-44 A-B). Oöcysts = 23-26 in diameter. Sporocysts = 7.2-9.1
x 3.5-5.0.
C. spinosa AZEVEDO, P. MATOS & E. MATOS, 1993: liver of Crenicichla lepidota:
Pará State, Brazil (measurements unavailable).
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 33
Myxoxporida spores: 2-1. Myxobolus associates; 2-2. M. cunhai; 2-3. M. inaequalis; 2-4. M. galaxii; 2-5.
M. kudoi; 2-6. M. lutzi; 2-7. M. magellanicus; 2-8. M. noguchii; 2-9. M. pygocentris; 2-10a. M. serrasalmi
(macrospore); 2-10b. M. serrasalmi (microspore); 2-11. M. stokesi; 2-12. Myxobolus sp. from Pimelodus
albicans; 2-13. Myxobolus sp. from Serrasalmus sp.; 2-14. Myxobolus sp. from Colossoma bidens; 2-15.
Myxobolus sp. from Curimata elegans (2-15. orig., others redrawn from PINTO (1928c, d) and
WALLIKER (1969)).
VIII. Plates of Protozoa and Ciliophora (Figs. 2–1 to 2–44)
2-1 2-2 2-3 2-4
2-5 2-6 2-7 2-8
2-9
2-10
2-11
2-13 2-14 2-15
A B
10 µm
2-12
34 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
2-16. Agarella gracilis (spore); 2-17 to 2-24. Henneguya spp. (spores): 2-17. H. iheringi; 2-18. H.leporinus;
2-19. H. lutzi; 2-20. H. wenyoni; 2-21. H. linearis; 2-22. H. oculta; 2-23. Henneguya sp. from Brycon
melanopterus; 2-24. Henneguya sp. from Mylossoma duriventris (2-23. & 2-24. orig.; 2-16. to 2-22. redrawn
from PINTO (1928 b-d).
2-17 2-182-16
2-19 2-20
2-21 2-22 2-23 2-24
10 µm
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 35
2-25. Myxidium cruzi; 2-26. M. fonsecai; 2-27. M. gurgeli; 2-28. Calyptospora sp. (Eimeridae) (2-25. to 2-
28. to same scale); 2-29. Balantidium piscicola; 2-30. Nyctotherus piscicola; 2-31. Ichthyophthirius multifilis
(2-28. orig., others redrawn from PINTO (1928 a, d)).
2-30 2-31
250 µm
2-26 2-272-25
2-28 2-2925 µm
25 µm
10 µm
36 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
2-32
10 µm
25 µm
2-33
2-35
2-34
10 µm
2-32. Trichodina fariai (lateral view); 2-33. Rhynchodinium paradoxum; 2-34. Trichodina fariai (oral
surface); 2-35. Trypanosoma sp. (2-32. to 2-34. redrawn from PINTO (1928d); 2-35. from FRÖES et al.
(1978)).
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 37
2-36. Henneguya sp. (cysts in gill filament of Mylossoma duriventris); 2-37. Henneguya sp. (spores from gill
filament of Semaprochilodus insignis); 2-38. Henneguya sp. (cysts in gill filament of Brycon melanoptera);
2-39. Myxobolus sp. (spores from liver of Semaprochilodus insignis). (Original photographs).
2-36 2-37
2-38 2-39
CyanMagentaYellowBlack page 37
38 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
2-40. Astyanax fasciatus from Cauca River, Colombia, with cysts of Henneguya sp.; 2-41. Curimata
elegans from Amazon River, near Belém, Pará, Brazil with cysts of Myxobolus sp. (Original
photographs).
2-40
2-41
CyanMagentaYellowBlack page 38
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 39
2-42. Myxobolus braziliensis mature spore (redrawn from CASAL et al. 1996); 2-43. Myxobolus inaequus
(redrawn from KENT & HOFFMAN 1984); 2-44. Calyptospora tucunarensis: A. mature sporocyst; B.
sporulated oöcyst (redrawn from BÉKÉSI & MOLNÁR 1991).
2-42 2-43
2-44
BA
40 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
IX. Cited and general references
BARASSA, B., CORDEIRO, N.S. & S. ARANA (2003): A new species of Henneguya, a gill parasite of
Astyanax altiparane (Pisces: Characidade) from Brazil, with comments and histopathology and
seasonality. - Mem. Inst. Oswaldo Cruz 98(6): 761-765.
BÉKÉSI, L. & K. MOLNÁR (1991): Calyptospora tucunarensis n. sp. (Apicomplexa : Sporozoa) from the
liver of tucunaré Cichla ocellaris in Brazil. - Systematic Parasitology 18: 127-132.
BOTELHO, C., JR. (1907): Sur deux nouveaux trypanosomes des poissons. - C.R. Soc. Biol. Paris
59(2): 128-129.
CASAL, G., MATOS, E. & C. AZEVEDO (1996): Ultrastructural data on the life cycle stages of
Myxobolus braziliensis n. sp., parasite of an Amazonian fish. - Europ. J. Protistol 32: 123-127.
CHEUNG, P.J., NIGRELLI, R.F. & G.D. RUGGIERI (1983): Coccidian parasite from the liver of the black
piranha, Serrasalmus niger SCHOMBURGK (Abstr.). - Eastern Fish Health Workshop, 21-23 June,
1983. Nat. Fish Health Res. Lab., Kearneysville, West Virginia: 3 pp.
CUNHA, A.M. & J.C.N. PENIDO (1926): Nouveau protozoaire parasite des poissons: Zelleriella piscicola
n. sp. - C.R. Soc. Biol. Paris 94: 1003.
CUNHA, A.M. & J.C.N. PENIDO (1927): Rynchodinium paradoxum n. gen., n. sp. protozoaire parasite
d’um poisson d’eau douce. - C.R. Soc. Biol. Paris 97(36): 1793-1794.
DADAY, E. (1905): Nyctotherus piscicola n. sp., ein neuer Fischparasit aus Südamerika. - Zool. Anz.
28: 233-238.
EARL, P.R. & G. JEMÉNEZ (1969): Nyctotherus dilleri n. sp. from the fish Cichlasoma fenestratum in
Veracruz. - Trans. Am. Mic. Soc. 88(2): 287-292.
EIRAS, J.C., MALTA, J.C., VARELA, A. & G.C. PAVANELLI (2004): Henneguya schizodon n. sp. (Myxosoa,
Myxobolidae), a parasite of the Amazonian teleost fish Schizodon fasciatus (Characiformes,
Anostomidae). - Parasite 11: 169-173.
FONSECA, F. (1935): Trypanosomas de peixes brasileiros. Decrição de uma nova espécie. - Mem.
Inst. Butantan 9: 151-184.
FONSECA, F. & Z. VAZ (1928a): Novos trypanosomas de peixes brasileiros. - Ann. Fac. Med. Univ.
São Paulo 3: 69-94.
FONSECA, F. & Z. VAZ (1928b): Trypanosoma francirochai n. sp. parasito de Otocinclus francirochai
HERRING, 1928 (peixe de água doce do Estado de São Paulo). - Bol. Biol. 11: 4-5.
FONSECA, F. & Z. VAZ (1929): Novas espécies de trypanosomas de peixes brasileiros de água doce.
- Bol. Biol. 13: 36-41.
FRÖES, O,M., FORTES, E., LIMA, D.F. & V.R.V. LEITE (1978): Três espécies novas de tripanosomas de
peixes de água doce do Brasil (Protozoa, Kinetoplastida). - Rev. Brasil. Biol. 38(2): 461-468.
HOFFMAN, G.L. (1999): Parasites of North American freshwater fishes. Second Edition. – Cornell
Univ. Press: 539 pp.
HORTA, P.P. (1910): Trypanosoma chagasi n. sp. parasito de Plecostomus punctatus. - Brasil Médico
24(28): 273.
HORTA, P.P. & A. MACHADO (1911): Estudos citológicos sôbre o “Trypanosoma chagasi” n. sp.
encontrado em peixes do gênero Plecostomus. - Mem. Inst. Oswaldo Cruz 3(2): 344-366.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 41
KENT M.L. & G.L. HOFFMAN (1984): Two new species of Myxozoa, Myxobolus inaequus sp. n. and
Henneguya theca sp. n. from the brain of a South American knife fish, Eigemannia virescens (V.). -
J. Protozool. 31(1): 91-94.
MARTINS, M.L., SOUZA, V.N., MORAES, J.R. & F.R. MORAES (1999): Gill infection of Leporinus
macrocephalus GARAVELLO & BRITSKI, 1988 (Osteichthyes: Anostomidae) by Henneguya leporinico-
la n. sp. (Myxozoa: Myxobolidae) description, histopathology and treatment. - Rev. Brasil.
Biol. 59(3): 537-534.
NEMECZEK, A. (1926): Beiträge zur Kenntnis der Myxosporidenfauna Brasiliens. - Arch. Protistenk.
54(1): 137-149.
OVERSTREET, R.M., HAWKINS, W.E. & J.W. FOURNIE (1984): The coccidian genus Calyptospora n. gen.
and family Calyptosporidae n. fam. (Apicomplexa), with members infecting primarily fishes. -
J. Protozool. 31(2): 332-339.
PENIDO, J.C.N. (1927): Quelques nouvelles Myxosporidies parasites des poisons d’eau douce du
Brésil. - C.R. Soc. Biol. Paris: 850-852.
PINTO, C. (1928a): Myxidium gurgeli nova espécie. Myxosporídeo parasito da vesícula biliar de peixe
de água doce do Brasil. - Sci. Med. 6(2): 86-87.
PINTO, C. (1928b): Henneguya wenyoni n. sp. myxosporidie parasite des branchies de poisson d’eau
douce du Brésil. - C.R. Soc. Biol. París 98(17): 1580.
PINTO, C. (1928c): Myxobolus noguchii, M. stokesi e Henneguya iheringi, espécies novas de myxosporídeos
de peixes de água doce do Brasil. - Bol. Biol. 12: 41-43.
PINTO, C. (1928d): Myxosporídeos e outros protozoários intestinais de peixes observados na
América do Sul. - Arch. Inst. Biol. 1: 101-136, 42 figs.
SOLANGI, M.A. & R.M. OVERSTREET (1980): Biology and pathogenesis of the coccidium Eimeria
funduli infecting killifishes. - J. Parasitol. 66(3): 513-526.
SPLENDORE, A. (1910): Trypanosomes de poisons brésiliens. - Bull. Soc. Path. Exot. 3: 521-524.
TAYLOR, R.L. (1978): Transmission of salmonid whirling disease by birds fed trout infected with
Myxosoma cerebralis. - J. Protozool. 25(1): 105-106.
WALLIKER, D. (1969): Myxosporidea of some Brazilian freshwater fishes. - J. Parasitol. 55(5):
942 - 948.
WOLF, K. (1982): Tubifex worms identified as essential hosts for salmonid whirling disease. - Res.
Infor. Bull. U. S. Fish & Wildlife Service: 2 pp.
42 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
3
MONOGENOIDEA
In collaboration with W. A. BOEGER and R. T. VIANNA
I. Definition and morphology
The Class Monogenoidea (also known as Monogenea or monogenetic trematodes)
consists of hermaphroditic mostly ectoparasitic platyhelminths with direct life-cycles. In
fishes, they inhabit the gills, skin, nasal fossae, ureters and a few are found in the intestinal
ducts. In amphibians and aquatic reptiles they may be found in the mouth, cloaca, or
urinary bladder. Exceptionally, species of monogenoids are reported from mammals
(hippopotamus) and invertebrates (ex. squid, copepods).
The most useful recognition feature of monogenoids is the posterior attachment
organ (haptor). This structure is usually flattened and frequently disk-like. It may be
armed with sclerotized structures such as anchors, bars (to support the anchors), and
hooks (Fig. 3-4D). In some genera, the haptor may have suckers, clamps or loculi along
with or in place of these sclerites. The anterior end of monogenoids can also attach to
hosttissue by means of adhesive secretions from the cephalic lobes that are stored on the
head organs. Two pairs of eyes are often present on the cephalic area, though in some
species these have been lost.
The digestive system of monogenoids consists of a mouth, a pharynx, an esophagus
and, usually, two intestinal ceca. These may be simple, have diverticula or be posteriorly
confluent. The female reproductive system contains a germarium (= ovary), oviduct,
ootype, seminal receptacle (sometimes absent), uterus, and one or two vaginae (these may
be absent as well). The male system includes a testis (or several), a vas deferens, a seminal
vesicle (saccate or as an expansion of the vas deferens) and a copulatory complex. The
copulatory complex is usually composed of a male copulatory organ (MCO) and an
accessory piece, that may be absent in some taxa. The MCO may be either muscular or
sclerotized and its morphology is important in the classification of the group. In some
genera, other sclerites may be associated with the reproductive system (e.g., a gonadal bar
in Gonocleithrum and a hook-like vaginal sclerite in Urocleidoides).
Monogenoidea is perhaps the least known taxon of fish parasites in the Amazon
region, which is also true for the entire Neotropical realm. Until the 1970’s, very few
species were known from Amazonian and Neotropical continental waters. The earliest
references of the taxon in Amazonian fish species are limited to fish kept in aquaria
abroad, mainly in the United States (see references of MIZELLE and coauthors). At that
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 43
time, very few local scientists contributed to the recovery of the richness of the group.
Undoubtedly, the collaboration between two fish parasitologists, VERNON E. THATCHER (at
that time in Cali, Colombia) and DELANE C. KRITSKY (Idaho State University, USA) and
subsequent efforts and collaborations represent the most intense and consistent effort
towards the understanding of the diversity of this group, especially in Brazilian waters.
Recently other groups have awakened to the abundance and richness of the Neotropical
Monogenoidea of freshwater fish species (ex. TAKEMOTO, LUQUE, VIOZZI and others).
While there are evidences of monogenoids with a broad host species spectrum
(KRITSKY et al. 1996 a, b & 1997 a, b), most show relatively high host specificity,
occurring on a single species or on closely related fish. The richness per host species
appears, however, to be highly variable. The red-breasted piranha (Pygocentrus nattereri)
hosts about 30 different species while many species of Siluriformes, for example, bear
a single or a few species. Most medium-sized and large fish harbor Monogenoidea. A
few such hosts have been reported to be negative for these parasites but it may be that
this merely reflects inadequate sampling methods. On the other hand, small fish
species have few monogenoids. We have searched intensively among the small
siluriforms (eg. whale catfishes and others) without turning up a single representative
of this group of worms. Characiform fish, especially Serrasalmidae, show the greatest
abundance of species of monogenoids.
Despite the efforts of taxonomists, the diversity of the Monogenoidea in the
Amazon and in the Neotropics is still largely unknown. Around 308 species are described
in approximately 70 genera, from 144 species of fish or an average of 2.14 species of
monogenoids per fish species. The family Dactylogyridae is overwhelmingly the most
abundant taxon in continental waters of South America. However, species of Gyrodactyl-
idae are being systematically described while only a few Diplectanidae, Monocotylidae and
Hexabothriidae appear to have representatives in these waters.
Assuming a conservative absence of species of monogenoid from 10 % of fish
species, a rough estimate of species of this clade of parasites suggest that fewer than 3
% of freshwater fish Monogenoidea are known. These estimates consider the most
recent evaluations of freshwater Neotropical fish species. Ichthyologists expect that
more than 6,025 species of freshwater fishes exist in this realm (MALABARBA & ROSA
2003). This estimated number of species of Monogenoidea may be greater, however,
since the composition of the monogenoid fauna of a single fish species may vary
greatly according to the geographic distribution (see Boeger & Kritsky 1988) and site
specificity of the host (even species known to harbor monogenoids have had few of the
possible microhabitats screened).
Although little is known about the association of the orders and families of hosts
and the genera of monogenoids, some indications are appearing. This is especially true of
the Dactylogyridae For example, species of Gussevia and Sciadicleithrum are reported solely
on Cichlidae; Anacanthorus spp are known only from Characiformes; Vancleaveus spp.,
Demidospermus spp. and Aphanoblastella spp are recorded from Pimelodidae Siluriformes;
while Amphithecium spp, Mymarothecium spp, Nothozothecium spp., and others, are unique to
Serrasalmidae hosts. There are, obviously, many other examples. In general one can guess
the parasite group if one knows the host species.
44 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
II. Life cycle and transmission
The life cycle of most monogenoids is direct in that all stages are completed on a single host.
These worms are also highly host specific and will develop on only one host species or on
closely related species of a single genus. Monogenoids can be either viviparous (some
Gyrodactylidae) or oviparous (all other families). In most cases, the larval stage (oncomira-
cidium) is ciliated and already has posterior sclerites (e.g., hooks and sometimes even
anchors) with which to attach to the same or a different host after hatching takes place. The
bands of cilia on the larva permit it to swim to a nearby fish of the same species. As the larva
settles down and begins to grow, the cilia are lost. The eggs of oviparous forms frequently
have one or more polar filaments that may serve to anchor them in the gill mucous until a
young adult hatches, with the haptoral sclerites already well formed. The eggs of oviparous
Gyrodactylidae have a drop of cement on the tip of a short filament that is used to “glue”
the egg on the external surface of their hosts. Viviparous gyrodactylids give birth to
complete worms, which already carry an offspring in the uterus when born.
According to HARRIS (1983), Oogyrodactylus farlowellae can complete its cycle from egg to
adult in 11 to 13 days at 27 °C. Other species probably have similarly short lifecycles.
III. Pathology
Most monogenoids attach superficially to the gill epithelium. They can move about at will
and generally produce little damage to the fish. However, even the relatively non-pathogenic
forms can produce extensive damage when large numbers are present on the gills. Direct
transmission, as observed in Monogenoidea, is greatly favored by proximity of hosts of the
same species and large populations of parasites develop rapidly. In the crowded conditions
of intensive pisciculture, monogenoids can rapidly become a problem. There are unreported
cases, especially on cultured Colossoma macropomum, in which specimens of apparently non-
pathogenic species of monogenoids were capable of consuming a significant proportion of
the gill tissue, leaving only cartilage in certain areas of the gill filaments.
Even if they do not cause excessive tissue damage, some monogenoids may provoke an
excessive production of mucus by the gill filaments. Apparently, such species feed on mucus
and its presence appears to stimulate the abundant production of this substance. Whatever the
cause, gill filaments coated with mucus have a reduced respiratory capacity. Thus, fish that
seem to tolerate heavy infestationsmay die suddenly when the oxygen content of the water
falls slightly. We should therefore consider all monogenoids as potentially harmful and try to
eliminate them from culture tanks, or at least control their numbers.
Most Neotropical monogenes belong to the family Dactylogyridae, which is
generally believed to include highly pathogenic species. Gyrodactylidae, with the excep-
tion of G. salaris, a notorious pathogen of salmon in European waters, are apparently less
pathogenic. In Europe, the species of Linguadactyla are known to provoke extensive
epithelial hyperplasia and the epithelium overgrows the haptor, which fixes the worm in
place (BYCHOWSKY 1957). These parasites feed on epithelial cells. A similar species,
Linguadactyloides brinkmanni THATCHER & KRITSKY, 1983, has been found on a Brazilian
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 45
Amazon food fish, Colossoma macropomum. This species appears more pathogenic since it
actively penetrates the tissues of the gill filament. This action is aided by secretions from
penetration glands that L. brinkmanni has located in the haptoral peduncle. When the
haptor has penetrated to the cartilaginous supporting rod of the filament, the anchors
directly engage this structure. As a host response, the cartilaginous tissue overgrows the
anchor points, effectively fixing the worm to a permanent location (Fig. 3-61).
The initial host response to the penetration of L. brinkmanni is basically an
inflammatory reaction. Both erythrocytes and leucocytes are numerous around the site of
the lesion. A funnel-like tube from the surface of the filament to the cartilage support is
maintained open by the constant movements of the worm. Apparently, this lesion
hemorrhages, at least initially. Epithelial hyperplasia occurs for some length along the
filament, and becomes more pronounced at the penetration site (Fig. 3-62). Epithelial
overgrowth at this site is probably a continuous process, which is partially checked by the
feeding activity of the worm. These parasites ingest blood cells as well as epithelium and
are usually red in color. The prolonged activities of this parasite can lead to the almost
complete destruction of the gill filaments (Fig. 3-63).
An as yet undescribed monogenoidean has been found on a doradid catfish that may
be even more pathogenic than L. brinkmanni. This species also penetrates to the cartilage,
but it does so from the other (lamellar) side of the filament (Fig. 3-64). The presence of
the haptor in the center of the filament provokes intensive cellular concentration and a
tumoroid growth that swells the filament and alters blood circulation.
IV. Prevention and treatment
Newly obtained fish, from whatever source, should be assumed to be infested and should be
treated before being introduced into a tank, pond, or aquarium containing other specimens
of the same or related species. Dip treatment can be used effectively against monogenoids
since they are relatively sensitive to chemicals and are in direct contact with the water.
Although many different chemical dips will dislodge monogenoids from living fish, the
easiest, most efficient and cheapest is a 1:4,000 solution of commercial formaldehyde (1 cm3
of formaldehyde for each 4 liters of water) used for 10-30 minutes. The time for immersion
in these dips is variable because different species of fish have different degrees of tolerance
for the chemicals. The sensitivity of the fish to the chemicals can also vary with water
temperature and the physiological condition of the individuals. One or two of the infested
fish should be treated first to test sensitivity before large scale treatment is attempted. At the
first sign of distress, the fish should be removed from the dip.
V. Collection and study methods
Based on the limited knowledge of the richness of the group, it is obvious that studies of
the alpha taxonomy of Monogenoidea are still essential in the Amazon region and in the
entire Neotropics. Taxonomic studies on the group, however, require basic scientific skills
46 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
and special care with the descriptions and proposal of new taxa in order to produce
robust knowledge to be applied in several areas of biology, including systematics, ecology,
and historical biogeography.
Freshwater monogenoids are usually very small. Some are as small as 200-300
micrometers long and, thus, are easily lost if the person collecting these animals is
untrained or the collection method is inadequate. Our experience has demonstrated that
the warm-water method (described below) is not only the best collection method
available, but also produces excellent specimens for morphological studies. This technique
allows rapid and adequate processing of specimens in the field, leaving the time-
consuming work of picking the worms from the gills and other organs to the laboratory,
where more adequate equipment and time are readily available.
Specimen preparation is also fundamental, for obvious reasons. In general, descrip-
tions of species involve cleared specimens, for the study of hard, sclerotized, structures,
and stained worms, which are necessary for the study of the morphology of internal
organs and structures and to complement the study of the sclerotized parts. The choice
of stain is fundamental and frequently makes the difference between an extensive and a
limited morphological characterization.
The use of phase contrast or, sometimes differential contrast microscopy is
necessary for precise illustrations and descriptions. Often, bad descriptions are caused by
the exclusive use of light microscoscopy which does not provide the resolution required
to see the fine details. Many taxonomic accounts fail to present detailed and adequate
morphological interpretations of the sclerotized parts of haptor, vagina, male copulatory
organ. These limitations repeatedly result in morphologic, taxonomic, and systematic
errors that greatly hinder the evolution of the knowledge in the group.
Illustrations, especially those of the hard sclerites, need to be very precise.
Frequently, species can be differentiated by small, frequently overlooked, inconspicuous
features of these structures. The most difficult structure to be illustrated is, by far, the
hook. Curiously, although the morphology of these structures is fundamental for the
systematic studies in the group, they receive the least attention from many investigators.
The structure of the male copulatory organ of many species, on the other hand requires
the most detailed morphological study and interpretation.
An important point to consider in taxonomic studies of Amazonian and Neotropical
Monogenoidea is the establishment and proposal of supra-specific taxa. While some genera
appear to represent clear specific groups, easily separated from other genera and groupings
by large morphological gaps (e.g., Curvianchoratus), many generic (or other supra-specific)
groupings are characterized by faint, often inconspicuous, morphological differences. In the
absence of an adequate phylogeny, the decision of proposing new supra-specific taxa
requires a “fish-eye-lens” study. Groupings of species are often recognized only after
extensive morphological study of many related species (in general, species of closely related
fish species) that allow the comprehension of shared characters, hopefully reflecting
common ancestry. Certification of the taxonomic status of these groups will certainly
depend on future phylogenetic reconstructions. Thus, a conservative approach is strongly
recommended and investigators working on this group of platyhelminths are urged to
exercise extreme caution in the proposal of supra-specific (and specific) taxa.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 47
Mistakes of the past are being repeatedin the present so a word of caution is
required. Except, perhaps, for lineages that invaded the Neotropical freshwater
environments recently, apparently from and with marine host lineages (e.g., the
freshwater dactylogyrids and diplectanids from Sciaenidae), most monogenoid parasites
of primary fish groups are unique to South and sometimes Central America. In the past,
Neotropical species were described as members of North American or European
genera, reflecting the lack of knowledge of the diversity of the group in the region. For
example, species of Urocleidus and Cleidodiscus, described from piranhas by MIZELLE and
co-authors (e.g., MIZELLE & PRICE 1965) are presently allocated to exclusively Neotropi-
cal genera (e.g., Amphithecium, Calpidothecium, Urocleidoides) (check KRITSKY et al. 1983,
and BOEGER & KRITSKY 1988 for many examples). Although the study of the group in
South America accumulated much information on species diversity there are still
unjustified attempts to include new species in genera with species from other continents
(e.g., Acolpenteron australe VIOZZI & BRUGNI, 2003 described from a Percichtyidae from
Argentina).
Most of the fauna of freshwater Monogenoidea of South America is closely related
to the African fauna (e.g., KRITSKY & BOEGER 1995). These faunas, however, are composed
of apparent sister but easily distinguishable generic groupings. Examples of genera with
species in the Neotropical region and elsewhere includes Euryhaliotrema, Diplectanum
(although there are strong indications that this genus does not represent a monophyletic
group) and Gyrodactylus. The latter, however, probably also represent an exceptional case
of rapid dispersion to other regions and continents of the globe, as suggested by BOEGER
et al. (2003). Summarizing, if a new species collected does not fit the diagnosis of
Neotropical genera, the investigator should seriously consider the possibility that it
represents the member of an undescribed genus.
Although common in the initial stages of the taxonomic studies of Amazonian and
Neotropical Monogenoidea, the use of specimens collected from aquarium fishes should
be accompanied by careful consideration of the type host species. Exchange of parasites
between hosts kept in captivity is very common, even between species of distantly related
higher categories of hosts (e.g., orders).
Collection of fish monogenoids is easily accomplished in the field and does not
require much more than buckets, a portable stove, formalin, ethanol (if DNA samples are
required), vials, labels, a notebook, and a pencil. It is, however, absolutely necessary that
animals are killed relaxed in order to allow adequate study of internal anatomy. The
method described below can be modified according to the local conditions, size of the
animal, and requirements of each specific study.
If monogenoids of the fish body surface are the object of the study, special care
should be given to the method of capture and handling of hosts. In general, gill nets and
trawl nets are not good fishing methods to meet this objective. Gill nets, however, may be
used if the fish is not left in the net and in the water for too long. Hook and line are great
for this purpose, but this method is not very efficient for catching fish of a variety of
species. Dip nets are fine and minnow traps are excellent.
Once collected, the fish should be killed by pithing, or other method, placed in a
container and washed with hot water (about 60-70 °C). The container should be
48 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
vigorously shaken in order to detach the parasites from the fish tissue. The “vigorously”
should be stressed as anything less than this may result in poor sampling of the parasite
population of a fish. The fish can be removed from the container, the liquid can be
decanted and fixed according to the objective of the study: in ethanol, formalin or both.
An adequate method, depending on the size of the fish, is to fix half of the decanted
liquid and sediments in formalin, for morphological studies, and the other half in ethanol,
if the investigator is interested in DNA studies. In this case, and in the procedures
described below, the final concentration for both methods of fixation would be about 4-
5 % of formalin and 70-80 % of ethanol, respectively.
Nasal cavities can be washed with hot water (about 60-70 °C) and scraped with a
probe into another vial. Fixation can be achieved in the same way described above. Gills
can be excised, the gill arches separated, placed in a vial, flooded with hot water (about 70-
75 °C). Once again, the vial should be vigorously shaken to detach parasites from the gill
tissue. Fixation, as in the other cases, should be accomplished with ethanol and formalin,
in the same concentrations, but the gill arches should accompany the sediment and liquid
in the formalin vial - if added to the ethanol vial, the ratio ethanol : tissue may result in
poor fixation and hinder later processing of the DNA.
Collection of internal Monogenoidea requires necropsy with the use of stereomicro-
scope and should be carried out in an adequate place, such a laboratory. In this case, fresh
or living host specimens should be used. Fixation can be performed with the same
methods mentioned above.
Slide making
A few comments are in order before we start. Monogenoids, especially the small
ones, are easily hydrated or dehydrated with ethanol, not requiring extensive time nor
long, stepwise, ethanol series. Hence, the methods of slide preparation in the group are
usually much simpler than for any other group of Platyhelminthes. Additionally, an
adequate morphological study of Monogenoidea requires specimens prepared for the
study of sclerotized (“hard”) structures and internal (“soft”) morphology.
Sclerotized structures may be studied through the clearing of the specimens in one
of two media: Hoyer’s Mounting Medium1 or Gray and Wess Mounting Medium2. Hoyer’s
clears faster, is more reliable but has two major problems: it may overly flatten the
specimen and they may not last as long as specimens mounted in Gray and Wess. Gray
and Wess, on the other hand, is not as reliable in producing nicely cleared specimens and
requires longer “incubation” in a oven or on a hot plate (at about 56 ºC) to produce good
1 Formula for Hoyer’s Mounting Medium-Chloral hydrate: 200 g; Crystalline gum Arabic: 30 g; Glycerol: 20 ml;
Distilled water: 50 ml. Dissolve gum arabic in distilled water and let it sit over night. Add the chloral hydrate and
glycerol and either filter the mixture through clean glass wool, or more efficiently, centrifuge the mixture. Store
Hoyer’s in a brown bottle to prevent degradation by light.
2 Formula for Gray and Wess Medium-PVA (polyvinyl alcohol) 71-24 powder: 2.0 g; 70 % acetone: 7.0 ml;
Glycerin: 5.0 ml; lactic acid: 5.0 ml; distilled water: 10.0 ml. Make a paste of the dry alcohol with acetone. Mix
half of the water with glycerin and lactic acid, stir into paste. Add remaining of water drop by drop while
stirring. Solution will be cloudy but becomes transparent if warmed in water bath for 10 min.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 49
specimens. This medium, however, is necessary if one applies the method indicated below
to observe and study the shield on the superficial bar of Gyrodactylidae.
In both cases, specimens that are kept in aqueous liquid (such as 4-5 % formalin) can
be directly transferred into a drop of either media on a glass slide. After orientation of the
specimen (preferably, with the ventral side up), a coverslip is placed on the drop of the
mounting medium and, especially in the case of Hoyer’s mounting media, it should be
sealed with transparent nail polish. Study of specimens prepared this way is necessarily
done with a phase-contrast or DIC microscope,as sclerites (such as anchors, bars and
hooks) are not readily visible with normal light microscopy.
Specimens to be used for the study of internal morphology should be stained with
Gomori’s trichrome3 as follows:
1. Place a drop of Gomori’s trichome in a small Petri dish and transfer 1-5 animals
from the formalin into this drop;
2. Stain the specimens for 1-5 minutes (according to the size of the specimens-it
would be wise to test the time with few specimens first);
3. Flood the dish with absolute ethanol;
4. Concentrate the specimens in the center of the dish by rotation of this container;
5. Pouring drops of water on the specimens should remove the stain from the overly
stained specimens (differentiation). This is the most important step in the process.
The organs should stain dark while the mesenchyma should be lightly stained
(usually light green).
6. Once the specimens are differentiated (as described above), the dish with ethanol
and the specimens should be lightly shaken in order to mix the remaining water
with the ethanol.
7. If only a few water drops were used, the specimens can, then, be cleared in
Beachwood (or synthetic) Creosote4, otherwise, it is recommended that the
specimens are further dehydrated in absolute ethanol prior to clearing.
8. With small specimens, it is better to place a drop of Creosote on a glass slide,
place the specimen in this liquid and, after it is cleared, carefully remove the
excess Creosote with a paper tissue.
9. Once cleared, the specimens can be mounted in Canada’s Balsam between slide
and coverslip.
The specimens prepared in this manner should be examined under normal
illumination but, often, the use of phase contrast and DIC helps in revealing some hidden
detail of sclerotized organs and parts.
Another method has been developed to allow visualization and study of sclerites
with very delicate and thins areas, which are extremely hard to differentiate using
specimens cleared in Hoyer’s or Gray and Wess.
3 Formula for Gomori’s Trichrome - Chromotrope 2R (CI 16570): 0.6 g; aniline blue: 0.6 g; phosphomolybdic
acid: 1.0 g; dissolve in distilled water: 100.0 ml; add hydrochloric acid: 1.0 ml. Allow to stand 24 hours in
refrigerator before use. Store in refrigerator and use cold.
4 Be especially careful passing the specimens from absolute ethanol into Creosote. If transfer is slow, the
ethanol dries rapidly and the specimen may dry.
50 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
This method was proposed by KRITSKY et al. (1978) and is extremely simple:
1. place one drop of Gomori’s trichrome on the center of a glass slide;
2. place the specimen you want to study in this drop;
3. Allow the specimen to stain for 30 s to 1 min;
4. Remove the excess of stain with a tissue paper (make a tip by twisting the paper
between your fingers and be careful not to remove the specimen);
5. Rapidly place a drop of Gray and Wess (not Hoyer’s) on the specimen;
6. Cover with a coverslip and put the slide in a warmer or oven (about 57 °C) for
1-2 days.
This slide can be studied under light microscope. As Gray and Wess is a water-base
stain, it will remove the excess stain. Sclerites stain blue, red or a mixture of both colors,
making small and very thin and delicate parts visible. This technique is fundamental for
the study of the morphology of the shield of the superficial bar of viviparous
Gyrodactylidae.
VI. Identification and keys
The keys that follow are intended solely as a support for the initial process of
determination of the taxa of specimens under study. Generic determination should be
checked using the diagnoses presented in the next part. There are no keys for species,
however. Species determination depends on the study of original literature based on the
list of species available for each genus and the list of references of the chapter. The
numbering of hooks used herein is that proposed by MIZELLE (1936). In this system,
numbering of hook pairs proceeds in an anterior-posterior direction ventrally and
posterior-anterior direction dorsally (when dorsal hooks are present) (examples in Figs. 3-
4A; 3-13A; 3-14A). Keys were prepared with the software DELTA Editor (DALLWITZ,
1980) and Key (DALLWITZ, 1974).
Key to higher taxa of freshwater Amazonian Monogenoidea
1. Haptor armed with a combination of hooks, anchors, bars, spines, squamodisc
................................................................................................................. (Polyonchoinea)..2
– Haptor armed with haptoral suckers or clamps ............................................................
................................................................................. (Heteronchoinea, Oligonchoinea)..4
2(1). 16 hooks, hinged, all marginal in a palmate, sucker-like haptor; viviparous or
oviparous worms. ......................................................................................Gyrodactylidae
– 14 hooks, not hinged, on a haptor of variable morphology; oviparous worms .. 3
3(2). Haptor sucker-like, crossed by septa; 14 hooks marginal; a single pair of ventral
anchors; bars absent; parasites of potamotrygonid rays .............................................
.................................................................................... Monocotylidae (Potamotrygonocotyle)
– Haptor sucker-like or otherwise, never with septa; 14 hooks; anchors, bars, and
other haptoral sclerites present or absent; parasites of Teleostei ...... Dactylogyrinea
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 51
4(1). Haptor armed with multiple clamps; parasites of Teleostei .......................................
.................................................................................................. Microcotylidae (Paranaella)
– Haptor with 6 haptoral suckers, each with haptoral sclerite; parasites of
potamotrygonid rays ............................................ Hexabothriidae (Paraheteronchocotyle)
Key to genera of freshwater Amazonian Gyrodactylidae
1. Oviparous worms ............................................................................................................... 2
– Viviparous worms .............................................................................................................. 5
2(1). Male copulatory organ (MCO) without accessory piece ........................................... 3
– Copulatory organ composed of MCO and accessory piece (Fig. 3-8B) ..................
..................................................................................................................... Nothogyrodactylus
3(2). Eggs in uterus more than 2, usually up to 10 or more ...................... Phanerothecium
– Eggs in uterus never more than one ............................................................................. 4
4(3). Muscular MCO without spines .................................................................. Oogyrodactylus
– Muscular MCO with spines ........................................................................... Hyperopletes
5(1). Ventral anchors, bars absent .....................................................................Anacanthocotyle
– Ventral anchor, bars (superficial and deep) present ................................................... 6
6(5). Cylindrical haptoral sclerite absent ................................................................................. 7
– Cylindrical haptoral sclerite present (Fig. 3-4B) .......................................... Accessorius
7(6). Superficial (anterior) bar with shield (Fig. 3-6E) or lacking posterior projections
.............................................................................................................................. Gyrodactylus
– Superficial (anterior) bar with double posterior projections similar to ribbons (Fig.
3-11B).................................................................................................................. Scleroductus
Key to genera of freshwater Amazonian Dactylogyrinea
1. Dorsal bar absent ............................................................................................................... 2
– Dorsal bar present, double ............................................................................................... 9
– Dorsal bar present, single ............................................................................................... 10
2(1). Hooks 14 on posterior margin of haptor ..................................................................... 3
– Hooks 14, 12 ventral, on posterior margin of haptor, 2 more central .................. 5
– Hooks 14 marginal ..................................................................................... Anacanthoroides
– Hooks 14, with anacanthorine distribution (6 dorsal, 8 ventral) ......... Anacanthorus
– Hooks 14, with ancyrocephaline distribution (4 dorsal, 10 ventral) ....................... 6
3(2). Haptor well set off from trunk ...........................................................................Kritskyia
– Haptor not differentiated from trunk ........................................................................... 4
4(3). Accessory piece one, non articulated to MCO ...........................................Pavanelliella
– Accessory piece articulated directly to MCO by copulatory ligament ..... Telethecium
5(2). Ventral bar with smooth surface on anterior margins; gonads tandem; germarium
anterior to testis; accessory piece articulated to MCO by copulatory ligament;
hook shank simple .......................................................................................... Cacatuocotyle
52 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
– Ventral bar with two submedian elongate processes; gonads overlapping;
accessory piece articulated directly to MCO; hook shank divided in two portions,
clearly defined .................................................................................................... Rhinonastes
6(2). Vagina ventral ...................................................................................................................... 7
– Vagina dextral, marginal ................................................................................................... 8
– Vagina sinistral, marginal ..................................................................................Rhinoxenus
7(6). Accessory piece one, not articulated to MCO; hook shank simple; ventral anchor
rod shaped ......................................................................................................... Trinidactylus
– Accessory piece articulated directly to MCO; hook shank divided in two portions,
clearly defined; ventral anchor with point, shaft, roots well defined ........................
.......................................................................................................................... Monocleithrium
– Accessory piece articulated to MCO by copulatory ligament; hook with entire
shank inflated, conferring a robust morphology to hook; ventral anchor with
point, shaft and roots not defined ..................................................................... Unibarra
8(6). Gonads tandem; testes multiple, anterior to germarium; ventral anchor robust,
with deep root longer than superficial ................................................ Linguadactyloides
– Gonads overlapping; testis single; ventral anchor with point, shaft and roots not
well defined ........................................................................................................... Trinigyrus
– Gonads tandem; germarium anterior to single testis; ventral anchor with point,
shaft, roots well defined ............................................................................ Euryhaliotrema
9(1). Vagina dextral, marginal; dorsal anchor modified, base apparently greatly
elongate, distorted, sometimes hook-like; ventral bar strongly V-shaped ................
........................................................................................................................ Curvianchoratus
– Vagina sinistral, marginal; dorsal anchor with shaft, point and base not clearly
separated in roots; ventral bar lip-shaped ................................................... Diplectanum
– Vagina dextral, ventral; dorsal anchor with shaft, point and base composed of two
roots; ventral bar slightly V-shaped ............................................................. Trinibaculum
10(1). Ventral bar with smooth surface on anterior margins ............................................. 11
– Ventral bar with short sclerotized muscle-attachment ........................ Euryhaliotrema
– Ventral bar with slightly projected margin, with or without medial cleft (Fig. 3-2B)
.............................................................................................................................................. 34
– Ventral bar with anterior transversal groove .............................................................. 35
– Ventral bar with antero-median projection ................................................................ 36
– Ventral bar with double umbeliform membranes on anterior margin .....................
.......................................................................................................................... Sciadicleithrum
11(10). Ventral anchor with point, shaft and roots not well defined .................................. 12
– Ventral anchor with point, shaft, base very elongated with roots not well defined
.........................................................................................................................Protorhinoxenus
– Ventral anchor with point, shaft, roots well defined ................................................ 15
– Ventral anchor robust, with elongate superficial and deep roots ..................... Jainus
12(11). Gonads overlapping ......................................................................................................... 13
– Gonads tandem; germarium anterior to testis ........................................................... 14
13(12). Eyes four; MCO coiled; hook pair 5 significantly distinct from other pairs; ventral
anchor filament robust, very conspicuous ........................................................ Gussevia
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 53
– Eyes absent; MCO somewhat straight or slightly curved; hook pair 5 similar to
other pairs; ventral anchor filament delicate, often inconspicuous ......... Heterotylus
14(12). Hooks 14, 8 dorsal, 6 ventral; anchors two pairs, dorsal ............................... Unilatus
– Hooks 14, with ancyrocephaline distribution (4 dorsal, 10 ventral); anchors ventral
pair, dorsal pair ............................................................................................ Demidospermus
15(11). MCO J-shaped .................................................................................................................. 16
– MCO sinuous .............................................................................................. Aphanoblastella
– MCO somewhat straight or slightly curved ............................................................... 18
– MCO coiled ....................................................................................................................... 27
16(15). Gonads overlapping; seminal vesicle C-shaped ......................................... Notothecium
– Gonads tandem; germarium anterior to testis; seminal vesicle fusiform ............ 17
17(16). Posterior projections on dorsal bar one ................................................. Demidospermus
– Posterior projections on dorsal bar two,ribbon-like ......................... Cosmetocleithrum
18(15). Seminal vesicle C-shaped ................................................................................................ 19
– Seminal vesicle fusiform ................................................................................................. 20
19(18). Vagina dextral, dorsal; dorsal bar strongly V-shaped ................................ Notothecium
– Vagina sinistral, dorsal; dorsal bar slightly U-shaped .............................Enallothecium
20(18). MCO single ....................................................................................................................... 21
– MCO double .................................................................................................................... 25
21(20). Anterior projections of dorsal bar absent .................................................................. 22
– Anterior projections of dorsal bar with small subterminal knob at each extremity
............................................................................................................................Philocorydoras
– Anterior projections of dorsal bar with single median projection .........................
......................................................................................................................... Mymarothecium
22(21). Vagina double ................................................................................................ Amphithecium
– Vagina single ...................................................................................................................... 23
23(22). Vagina middorsal, looping left caecum ..................................................... Notothecioides
– Vagina sinistral marginal ................................................................................................. 24
– Vagina dextral, dorsal ................................................................................. Mymarothecium
24(23). Gonads overlapping; dorsal bar slightly V-shaped; posterior projections on dorsal
bar absent ....................................................................................................... Calpidothecium
– Gonads tandem; germarium anterior to testis; dorsal bar strongly V-shaped; single
posterior projection on dorsal bar ........................................................... Demidospermus
25(20). Vagina double ................................................................................................ Amphithecium
– Vagina single ...................................................................................................................... 26
26(25). Vagina sclerotized, dextral, marginal; ventral bar slightly U-shaped; tegument scaled
........................................................................................................................ Pithanothecium
– Vagina muscular, sinistral, dorsal; ventral bar rod-shaped; tegument smooth ........
............................................................................................................................Heterothecium
27(15). Posterior projection on dorsal bar absent ................................................................... 28
– Posterior projection on dorsal bar one ........................................................................ 33
– Posterior projections on dorsal bar two, ribbon-like ......................... Cosmetocleithrum
28(27). Ventral bar without posterior median projection ...................................................... 29
– Ventral bar with posterior median projection ............................................................ 32
54 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
29(28). Accessory vaginal sclerite absent .................................................................................. 30
– Accessory vaginal sclerite present ................................................................Urocleidoides
30(29). Accessory sclerite associated with base of ventral anchor absent ........................ 31
– Accessory sclerite associated with base of ventral anchor present ......................
........................................................................................................................... Tereancistrium
31(30). Hook pair 5 similar to other pairs; ventral anchor filament delicate, often
inconspicuous; gonadal bar present .......................................................... Gonocleithrum
– Hook pair 5 significantly distinct from other, reduced; ventral anchor filament
robust, very conspicuous; gonadal bar absent ................................................. Gussevia
32(28). Eyes four; accessory piece one, non articulated to MCO; vagina sinistral, marginal;
dorsal bar slightly V-shaped ..................................................................... Aphanoblastella
– Eyes absent; accessory piece articulated to MCO by copulatory ligament; vagina
sinistral, ventral; dorsal bar slightly U-shaped ................................... Pseudovancleaveus
33(27). Gonads overlapping; ventral bar rod-shaped; accessory sclerite associated with
base of ventral anchor present ................................................................... Tereancistrium
– Gonads tandem; germarium anterior to testis; ventral bar strongly V-shaped;
accessory sclerite associated with base of ventral anchor absent ...........................
......................................................................................................................... Demidospermus
34(10). Eyes four; vagina sclerotized, single; dorsal bar slightly U-shaped ......... Odothecium
– Eyes two; vagina muscular, double; dorsal bar slightly V-shaped ..............................
....................................................................................................................... Calpidothecioides
35(10). Prostatic reservoirs unknown; hook pair 5 similar to other pairs; ventral anchor
filament delicate, often inconspicuous .................................................... Ancistrohaptor
– Prostatic reservoirs round to short, ovate; hook pair 5 significantly distinct from
other, reduced; ventral anchor filament robust, very conspicuous ............. Gussevia
36(10). Accessory piece one, non articulated to MCO .......................................................... 37
– Accessory piece articulated directly to MCO ............................................................ 39
– Accessory piece articulated to MCO by copulatory ligament ................................ 41
37(36). Eyes four; prostatic reservoirs round to ovate; annulations on body absent;
seminal vesicle with thin walls, of variable length .................................................... 38
– Eyes absent; prostatic reservoirs very long, often looping posteriorly; annulations
on body present; seminal vesicle with thick walls, very long, extending from level
of base of MCO to initial portion of germarium ..................................... Vancleaveus
38(37). Ventral anchor with point, shaft, roots well defined; ventral bar slightly V-shaped,
without any posterior median projection ............................................... Diaphorocleidus
– Ventral anchor robust, with elongate superficial and deep roots; ventral bar rod-
shaped, with posterior median projection ............................................................. Jainus
39(36). MCO J-shaped ...............................................................................................Notozothecium
– MCO somewhat straight or slightly curved .......................................... Mymarothecium
– MCO coiled ....................................................................................................................... 40
40(39). Seminal vesicle two, fusiform;ventral bar rod-shaped; gonadal bar absent ...........
...............................................................................................................................Dawestrema
– Seminal vesicle fusiform; ventral bar slightly U-shaped; gonadal bar present .......
........................................................................................................................... Gonocleithrum
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 55
41(36). MCO J-shaped .................................................................................................................. 42
– MCO somewhat straight or slightly curved .......................................... Mymarothecium
– MCO coiled .................................................................................................... Ameloblastella
42(41). Vagina sinistral marginal; dorsal anchor with shaft, point and base composed of
two roots ...................................................................................................Annulotrematoides
– Vagina dextral, dorsal; dorsal anchor robust with deep root longer than superficial
root ...................................................................................................................Notozothecium
Clave para las taxas superiores de Monogenoidea Neotropicales de agua dulce
1. Haptor armado con una combinación de ganchos, áncoras, barras, espinas,
escuamodiscos ..................................................................................... (Polyonchoinea)..2
– Haptor armado con ventosas haptoriales o tenazas .....................................................
................................................................................. (Heteronchoinea, Oligonchoinea)..4
2(1). 16 ganchos, articulados, todos marginales en un haptor palmeado y con forma de
ventosa; helmintos vivíparos u oviparos ..............................................Gyrodactylidae
– 14 ganchos, sin articulación; haptor de morfología variable; helmintos ovíparos
................................................................................................................................................ 3
3(2). Haptor como ventosa, cruzado por un septo; 14 ganchos marginales; un único par
de áncoras ventrales; barras ausentes; parásitos de rayas potamotrygonideas ........
.................................................................................... Monocotylidae (Potamotrygonocotyle)
– Haptor como ventosa o no, nunca con septos; 14 ganchos; áncoras, barras y otras
 escleritas presentes o ausentes en el raptor; parásitos de Teleostei .........................
.......................................................................................................................Dactylogyrinea
4(1). Haptor armado con múltiples tenazass; parásitos de Teleostei .................................
.................................................................................................. Microcotylidae (Paranaella)
– Haptor con 6 ventosas en el haptor, cada una con escleritas haptorial; parásito de
rayas potamotrygonideas .................................... Hexabothriidae (Paraheteronchocotyle)
Clave para los géneros de Gyrodactylidae Neotropicales de agua dulce
1. Helmintos ovíparos ............................................................................................................ 2
– Helmintos vivíparos ........................................................................................................... 5
2(1). Organo copulador masculino (OCM) simple sin piezas accesorias. ....................... 3
– Organo copulador compuesto por OCM y pieza accesoria (Fig. 3-8B) ..................
..................................................................................................................... Nothogyrodactylus
3(2). Más de 2 huevos dentro del útero, generalmente hasta 10 ................ Phanerothecium
– Nunca más de 1 huevos dentro del útero ..................................................................... 4
4(3). OCM muscular sin espinas ......................................................................... Oogyrodactylus
– OCM muscular con espinas ........................................................................... Hyperopletes
5(1). Ancoras ventrales presentes, barras ausentes ........................................Anacanthocotyle
– Ancoras ventrales presentes, barras (superficiales y profundas) presentes ............ 6
56 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
6(5). Esclerita haptorial cilíndrica ausente .............................................................................. 7
– Esclerita haptorial cilíndrica presente (Fig. 3-4B) ....................................... Accessorius
7(6). Barra ventral (anterior) con escudo (Fig. 3-6E) o sin proyecciones posteriores ....
.............................................................................................................................. Gyrodactylus
– Barra ventral (anterior) con proyecciones posteriores dobles similares a cintas
(Fig. 3-11B) ......................................................................................................... Scleroductus
Clave para los Dactylogyrinea Neotropicales de agua dulce
1. Barra dorsal ausente .......................................................................................................... 2
– Barra dorsal presente, doble ............................................................................................ 9
– Barra dorsal presente, única ........................................................................................... 10
2(1). 14 ganchos en el margen posterior del haptor ............................................................ 3
– 14 ganchos, 12 ventrales, en el margen posterior del haptor, 2 más centrales ..... 5
– 14 ganchos marginales .............................................................................. Anacanthoroides
– 14 ganchos, con distribución anacantorina (6 dorsales, 8 ventrales) ...... Anacanthorus
– 14 ganchos, con distribución ancirocefalina (4 dorsales, 10 ventrales) .................. 6
3(2). Haptor bien diferenciado del tronco .................................................................Kritskyia
– Haptor no diferenciado del tronco ................................................................................ 4
4(3). Pieza accesoria único, no-articulada al OCM..............................................Pavanelliella
– Pieza accesoria directamente articulada al órgano copulador masculino (OCM)
por el ligamento copulador .............................................................................. Telethecium
5(2). Barra ventral con superficie lisa en el margen anterior; gónadas en hilera;
germarium anterior a los testículos; pieza accesoria articulada al OCM por el
ligamento copulatorio; cuerpo del gancho simple. .................................. Cacatuocotyle
– Barra ventral con dos procesos submedianos alargados; gónadas sobrepuestas; la
pieza accesoria articulada directamente al OCM; parte final del gancho dividido
en dos porciones claramente definidas ........................................................ Rhinonastes
6(2). Vagina ventral ...................................................................................................................... 7
– Vagina derecha, marginal .................................................................................................. 8
– Vagina izquierda, marginal ...............................................................................Rhinoxenus
7(6). Pieza accesoria única, no-articulada al OCM; cuerpo del gancho es simple; áncora
ventral en forma de varilla ............................................................................. Trinidactylus
– Pieza accesoria articulada directamente a la OCM; cuerpodel gancho dividido en
dos porciones claramente definidas; áncora ventral con punta, cuerpo y base bien
definidas ......................................................................................................... Monocleithrium
– Pieza accesoria articulada a OCM por el ligamento copulador; gancho con todo
cuerpo inflado, confiriéndole una morfología robusta al gancho; áncora ventral
con punta, cuerpo y base no definida ............................................................... Unibarra
8(6). Gónadas en hilera; testículos múltiples, anteriores al germarium; áncora ventral
robusta con raíz profunda más larga que superficial ....................... Linguadactyloides
– Gónadas sobrepuestas; testículo único; áncora ventral en punta, cuerpo y raíces
base indefinidos .................................................................................................... Trinigyrus
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 57
– Gónadas en hilera; germario anterior al único testículo; áncora ventral con punta,
cuerpo y raíces bien definidos .................................................................. Euryhaliotrema
9(1). Vagina dextral, marginal; áncora dorsal modificada, base aparentemente muy
alargada, distorsionada, algunas veces en forma de gancho; barra ventral en
forma de V .................................................................................................. Curvianchoratus
– Vagina sinistral, marginal; áncora dorsal con cuerpo, punta y base sin separación
clara con las raíces; barra ventral en forma de labio ................................ Diplectanum
– Vagina dextral, ventral; áncora dorsal con cuerpo, punta y base compuesto de dos
raíces; barra ventral ligeramente en forma de V ...................................... Trinibaculum
10(1). Barra ventral con superficie lisa en los márgenes anteriores .................................. 11
– Barra ventral con corta proyección muscular esclerotizada .............. Euryhaliotrema
– Barra ventral con margen ligeramente proyectado, con o sin hendidura media (Fig.
3-2B) ................................................................................................................................... 34
– Barra ventral con estría antero-transversal ................................................................. 35
– Barra ventral con proyecciones antero-mediana ....................................................... 36
– Barra ventral con doble membrana umbeliforme en el margen anterior ................
.......................................................................................................................... Sciadicleithrum
11(10). Ancora ventral con punta, cuerpo y raíces sin definición ....................................... 12
– Ancora ventral con punta, cuerpo, base muy alargada con raíces no definidas .....
.........................................................................................................................Protorhinoxenus
– Ancora ventral con punta, cuerpo, raíces bien definidas ......................................... 15
– Ancora ventral robusta, con raíces superficiales y profundas alargadas ......... Jainus
12(11). Gónadas sobrepuestas ..................................................................................................... 13
– Gónadas en hileras; germario anterior al testículo ................................................... 14
13(12). Cuatro ojos; OCM enrollado; el quinto par de ganchos significativamente distinto de
los otros pares; filamento del áncora ventral robusto, muy conspicuo ......... Gussevia
– Ojos ausentes; OCM casi recto o ligeramente curvado; quinto par de ganchos
similar a los otros pares; filamento del áncora ventral delicado, con frecuencia
insconspicuo ........................................................................................................ Heterotylus
14(12). 14 ganchos, 8 dorsales, 6 ventrales; 2 pares de áncoras dorsales ................. Unilatus
– 14 ganchos, con distribución ancirocefalina (4 dorsales, 10 ventrales); par de
áncoras ventrales; par de áncoras dorsales ............................................ Demidospermus
15(11). OCM en forma de J ........................................................................................................ 16
– OCM sinuoso .............................................................................................. Aphanoblastella
– OCM casi recto o ligeramente curvado ...................................................................... 18
– OCM enrollado ................................................................................................................. 27
16(15). Gónadas sobrepuestas; vesícula seminal en forma de C ......................... Notothecium
– Gónadas en hilera; germario anterior al testículo; vesícula seminal fusiforme ......
.............................................................................................................................................. 17
17(16). Proyecciones posteriores en la primera barra dorsal ........................... Demidospermus
– Proyecciones posteriores en la segunda barra dorsal, en forma de cinta ................
....................................................................................................................... Cosmetocleithrum
18(15). Vesícula seminal en forma de C .................................................................................... 19
– Vesícula seminal fusiforme ............................................................................................ 20
58 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
19(18). Vagina dextral, dorsal; barra dorsal em forma de V ................................ Notothecium
– Vagina sinestral, dorsal; barra dorsal ligeramente en forma de U .......Enallothecium
20(18). OCM único ........................................................................................................................ 21
– OCM doble ........................................................................................................................ 25
21(20). Proyecciones anteriores de la barra dorsal ausentes ................................................. 22
–Proyecciones anteriores de la barra dorsal con pequeños nudos subterminales en
cada extremidad ..............................................................................................Philocorydoras
– Proyecciones anteriores de la barra dorsal con proyección media única .................
......................................................................................................................... Mymarothecium
22(21). Vagina doble ................................................................................................... Amphithecium
– Vagina única ...................................................................................................................... 23
23(22). Vagina dorsal media, circundando el intestino izquierdo ...................... Notothecioides
– Vagina sinestral marginal ................................................................................................ 24
– Vagina dextral, dorsal ................................................................................. Mymarothecium
24(23). Gónadas sobrepuestas; barra dorsal ligeramente en forma de V; proyecciones
posteriores ausentes en la barra dorsal .................................................... Calpidothecium
– Gónadas en hilera; germario anterior al testículo; barra dorsal en forma de V;
proyección única posterior en la barra dorsal ....................................... Demidospermus
25(20). Vagina doble ................................................................................................... Amphithecium
– Vagina única ......................................................................................................................26
26(25). Vagina esclerotizada, destral, marginal; barra ventral ligeramente en forma de U;
tegumento con escamas .............................................................................. Pithanothecium
– Vagina muscular, sinestral, dorsal; barra ventral en forma de varilla; tegumento liso
............................................................................................................................Heterothecium
27(15). Proyección posterior ausente en la barra dorsal ........................................................ 28
– Proyección posterior en la primera barra dorsal ....................................................... 33
– Proyecciones posteriores en la segunda barra dorsal, en forma de cinta ................
....................................................................................................................... Cosmetocleithrum
28(27). Barra ventral sin proyección mediana posterior ........................................................ 29
– Barra ventral con proyección mediana posterior ...................................................... 32
29(28). Esclerita accesoria vaginal ausente ............................................................................... 30
– Esclerita accesoria vaginal presente .............................................................Urocleidoides
30(29). Esclerita accesoria asociada a la base del áncora ventral ausente .......................... 31
– Esclerita accesoria asociada a la base del áncora ventral presente ......................
........................................................................................................................... Tereancistrium
31(30). Par de ganchos 5 similar a los otros pares; filamento del áncora ventral delicado,
con frecuencia incospicuo; barra gonadal presente ............................... Gonocleithrum
– Par de ganchos 5 significativamente distinto de los otros, reducido; filamento del
áncora ventral robusto, muy conspicuo; barra gonadal ausente .................. Gussevia
32(28). Cuatro ojos; primera pieza accesoria no articulada al OCM; vagina sinestral,
marginal; barra dorsal ligeramente en forma de V ............................. Aphanoblastella
– Ojos ausentes; pieza accesoria articulada al OCM por ligamento copulatorio; vagina
sinistral, ventral; barra dorsal ligeramente en forma de U ................ Pseudovancleaveus
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 59
33(27). Gónadas sobrepuestas; barra ventral en forma de varilla; esclerita accesoria
asociada a la base del áncora ventral presente ........................................ Tereancistrium
– Gónadas en hilera; germarium anterior al testículo; barra ventral en forma de
V; esclerita accesoria asociada a la base del áncora ventral ausente ...................
......................................................................................................................... Demidospermus
34(10). Cuatro ojos; vagina esclerotizada, única; barra dorsal ligeramente en forma de U
................................................................................................................................ Odothecium
– Dos ojos; vagina muscular, doble; barra dorsal ligeramente en forma de V ..........
....................................................................................................................... Calpidothecioides
35(10). Reservorios prostáticos desconocidos; par de ganchos 5 similar a los otros
pares; filamento del áncora ventral delicado, frecuentemente incospicuo ...........
.......................................................................................................................... Ancistrohaptor
– Reservorios prostáticos cortos, redondos u ovalados; par de ganchos 5
significativamente diferentes de los otros, reducidos; filamento del áncora ventral
robusto, muy conspicuo ........................................................................................ Gussevia
36(10). Pieza accesoria unica no articulada al OCM .............................................................. 37
– Pieza accesoria articulada directamente al OCM ...................................................... 39
– Pieza accesoria articulada al OCM por el ligamento copulatorio .......................... 41
37(36). Cuatro ojos; reservorios prostáticos redondos a ovalados; cuerpo sin anillos;
vesícula seminal con paredes delgadas de longitud variable ................................... 38
– Ojos ausentes; reservorios prostáticos muy largos, frecuentemente dando la vuelta
posteriormente; anillos presentes en el cuerpo; vesícula seminal con paredes
gruesas, muy larga, extendiendose desde el nível de la base del OCM hasta la parte
inicial del germarium ........................................................................................ Vancleaveus
38(37). Ancora ventral con punta, cuerpo, raíces bien definidas; barra ventral ligeramente
en forma de V, sin ninguna proyección posterior mediana ............... Diaphorocleidus
– Ancora ventral robusta, con raíces superficiales y profundas alargadas; barra
ventral en forma de varilla, con proyección posterior mediana ........................ Jainus
39(36). OCM en forma de J .....................................................................................Notozothecium
– OCM casi recto o ligeramente curvado ................................................. Mymarothecium
– OCM enrollado ................................................................................................................. 40
40(39). Dos vesículas seminales, fusiformes; barra ventral em forma de varilla; barra
gonadal ausente .................................................................................................Dawestrema
– Vesícula seminal fusiforme; barra ventral ligeramente en forma de U; barra
gonadal presente ............................................................................................ Gonocleithrum
41(36). OCM en forma de J ........................................................................................................ 42
– OCM casi recto o ligeramente curvo ..................................................... Mymarothecium
– COM enrollado .............................................................................................. Ameloblastella
42(41). Vagina sinestral marginal; áncora dorsal con cuerpo, punta y base compuesta de
dos raíces ...................................................................................................Annulotrematoides
– Vagina destral, dorsal; áncora dorsal robusta con raíz profunda más larga que la
raíz superficial ................................................................................................Notozothecium
60 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
VII. Checklist of Monogenoidea from Amazonian freshwater fishes and diagnoses
The diagnoses and list of species below refer solely to those species of Mono-
genoidea from the Amazon Region or from fish groups (species, genera) that are
known to occur in this region, even though some of the species are originally
reported from other areas. A list of species of genera of uncertain taxonomic validity
is presented at the end of this section. The descriptions were prepared with the
software DELTA Editor (DALLWITZ, 1980).
Subclass Heteronchoinea BOEGER & KRITSKY, 2002
Infrasubclass Oligonchoinea BYCHOWSKY, 1937
Hexabothriidae PRICE, 1942
Body elongate, fusiform. Oviparous. Spike sensilla absent. Eyes, eye
granules absent. Mouth terminal; oral sucker present, pharynx bulbous.
Ceca non-confluent, with diverticula. Copulatory organ (MCO) muscular,
armed with spines or not. Testes multiple, post-germarian. Germarium
elongate, U-shaped; genito-intestinal canal present. Vagina two, bilateral,
ventral; ductus vaginalis. Haptor round to ovate, armedwith three pairs of
haptoral suckers with hook-like sclerites; haptoral appendix present with
pair of suckers, hooks, pair of anchors; hooks present or absent in adult;
anchors present or absent.
Paraheteronchocotyle MAYES, BROOKS & THORSON, 1981
Body elongate. MCO muscular, composed of two portions; distal portion
elongate, unarmed; proximal portion elongate with thick walls; prostatic
region absent. Proximal germarium lobate, descending branch sinuous,
ascending branch absent; oviduct dilated. Ootype smooth, lacking longitu-
dinal rows of cells. Haptor asymmetrical; haptoral sucker distributed
linearly, except a pair adjacent to haptoral appendix. Haptoral appendix
marginal, anchors absent. Eggs with one long filament. Parasites of species
of Potamotrygonidae rays.
Type and only species: Paraheteronchocotyle amazonensis MAYES, BROOKS &
THORSON, 1981 from Potamotrygon circularis. (Figs. 3-1 A-C).
Microcotylidae TASCHENBERG, 1879
Body elongate, fusiform. Oviparous. Spike sensilla absent. Eyes, eye granules
absent. Mouth terminal; buccal organs present, pharynx bulbous. Ceca non-
confluent with diverticula. Copulatory organ (MCO) present or absent,
genital atrium muscular, usually armed with spines. Testes multiple, post-
germarian. Germarium elongate, double-inverted-U-shaped; genito-intesti-
nal canal present. Vagina dorsal; ductus vaginalis. Haptor elongate, armed
with multiple microcotylid clamps (n>8); hooks, anchors, bars absent.
Paranaella KOHN, BAPTISTA-FARIAS & COHEN, 2000
Body lanceolate. Haptor subsymmetrical with two subequal rows of
clamps, similar in shape. Buccal organs with septum. MCO non-differenti-
ated. Genital atrium armed with two concentric rows of spines around
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 61
muscular aperture. Eggs with one filament each. Vagina mid-dorsal,
unarmed. Parasites of gills of species of Loricariidae (Siluriformes).
Type and only species: Paranaella luquei KOHN, BAPTISTA-FARIAS & COHEN,
2000 from Hypostomus sp., Rhinelepis aspera, Hypostomus regani. (Figs. 3-2 A-B).
Subclass Polyonchoinea
Monocotylidae TASCHENBERG, 1879
Body robust to fusiform. Oviparous. Spike sensilla absent. Eyes present or
absent. Haptor sucker-shaped, usually divided by septa. Oral sucker present.
Pharynx single, bulbous. Ceca non-confluent. Copulatory organ (MCO)
sclerotized, lacking accessory piece. Germarium loops right intestinal ceca.
Vagina ususally present. Testis single, post-germarian. Hooks dactylogyrid,
14 marginal. Ventral anchor present or absent. Dorsal anchor, bars absent.
Potamotrygonocotyle MAYES, BROOKS & THORSON, 1981
Eyes absent; eye granules present or absent. Tegument smooth. Vagina
sinistro-marginal, muscular.. Hooks with simple shank. Ventral anchor pair
present. Haptor divided ventrally into eight external loculi, one central; septa
lacking sinuous ridges or sclerites; dorsal surface of haptor with six muscular
papillae. Parasites of the gills of Potamotrygonidae species (Rajiformes).
Type and only species: P. tsalickisi MAYES, BROOKS & THORSON, 1981 from
Potamotrygon circularis. (Figs. 3-3 A-B).
Gyrodactylidae VAN BENEDEN & HESSE, 1863
Oviparous or viviparous. Spike sensilla present. Eyes granules absent.
Haptor sucker-shaped. Pharynx two bulbous subunits, distal frequently with
finger-like projections. Ceca non-confluent. Copulatory organ (MCO) mus-
cular or sclerotized; when muscular it may be elongate, form a cirrus sac, or
be bulbous. Accessory piece present, absent. Germarium usually ovate, with
an internal fertilization chamber. Vagina absent. Hooks gyrodactylid. Hooks
16 marginal. Hooks on finger-like projections, or not on peduncles. Ventral
anchor present or absent. Dorsal anchor, bar absent. Ventral anchor
gyrodactylid (long superficial root, knob-like deep root). Deep bar (associat-
ed with knobs of anchors) present when ventral anchor is present.
Accessorius JARA, AN & CONE, 1991
Viviparous. Peduncle conspicuous. Haptor sucker-shaped. Copulatory organ
only represented by MCO. MCO muscular, bulbous, with spines. Ventral
anchor present. Cylindrical haptoral sclerite present. Superficial bar present,
rod-shaped. Deep bar (associated with knobs of anchors) present. Parasites
of external body surface of species of Characidae (Characiformes).
Type and only species: Accessorius peruensis JARA, AN & CONE, 1991 from
Lebiasina bimaculata (Figs. 3-4 A-F).
Anacanthocotyle KRITSKY & FRITTS, 1970
Viviparous. Peduncle conspicuous. Haptor cylindrical or sucker-shaped.
Copulatory organ represented only by MCO, muscular, bulbous, with spines.
Ventral anchor, bars absent. Cylindrical haptoral sclerite absent. Parasites of
the external surface of species of Characidae (Characiformes).
62 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
Type and only species: A. anacanthocotyle KRITSKY & FRITTS, 1970 from
Astyanax fasciatus (Figs. 3-5 A-C).
Gyrodactylus NORDMANN, 1832
Synonyms: Paragyrodactyloides; Paragyrodactylus.
Viviparous. Peduncle conspicuous. Copulatory organ represented only by
MCO, muscular, bulbous, with spines. Cylindrical haptoral sclerite absent.
Ventral anchor present. Superficial bar present, rod-shaped, with or without
a shield. Parasites of gills and external surfaces of species of Clupeiformes,
Cyprinodontiformes, Perciformes, Siluriformes, Characiformes.
G. anisopharynx POPAZOGLO & BOEGER, 2000 from Corydoras paleatus, Corydoras
ehrhardtii (Callichthyidae, Siluriformes).
G. bimaculatus AN, JARA & CONE, 1991 from Lebiasina bimaculata (Characidae,
Characiformes).
G. bullatarudis TURNBULL, 1956 from Poecilia sphenops, Poecilia reticulata (Poecili-
idae, Cyprinodontiformes).
G. costaricensis KRITSKY & FRITTS, 1970 from Poecilia sphenops (Poeciliidae,
Cyprinodontiformes).
G. gemini FERRAZ, SHINN & SOMMERVILLE, 1994 from Semaprochilodus taeniurus
(Curimatidae, Characiformes).
G. geophagensis BOEGER & POPAZOGLO, 1995 from Geophagus brasiliensis (Cichl-
idae, Perciformes) (Figs. 3-6 A-E).
G. lebiasinus AN, JARA & CONE, 1991 from Lebiasina bimaculata (Characidae,
Characiformes).
G. milleri HARRIS & CABLE, 2000 from Poecilia caucana (Poecilidae, Cyprinodon-
tiformes).
G. neotropicalis KRITSKY & FRITTS, 1970 from Astyanax fasciatus (Characidae,
Characiformes).
G. pictae CABLE, VAN OOSTERHOUT, BARSON & HARRIS, 2005 from Poecilia picta
(Poeciliidae, Cyprinodontiformes).
G. pimelodellus AN, JARA & CONE, 1991 from Pimelodella yuncensis (Pimelodidae,
Siluriformes).
G. poeciliae HARRIS & CABLE, 2000 from Poecilia caucana (Poecilidae, Cyprin-
odontiformes).
G. samirae POPAZOGLO & BOEGER, 2000 from Corydoras ehrhardtii, Corydoras
paleatus (Callichthyidae, Siluriformes).
G. slendrus AN, JARA & CONE, 1991 from Lebiasina bimaculata (Characidae,
Characiformes).
G. superbus POPAZOGLO & BOEGER, 2000 from Corydoras paleatus, Corydoras
ehrhardtii (Callichthyidae, Siluriformes).
G. trairae BOEGER & POPAZOGLO, 1995 from Hoplias malabaricus (Erythrinidae,
Characiformes).
G. turnbulli HARRIS & LYLES, 1992 from Poecilia reticulata (Poeciliidae, Cyprin-
odontiformes).
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 63
Hyperopletes BOEGER, KRITSKY & BELMONT-JÉGU, 1994
Oviparous. Peduncle conspicuous. Copulatory organ represented only by
MCO, muscular, sac-like, with spines. Only one egg in uterus. Ventral anchor
present. Cylindrical haptoral sclerite absent. Superficial bar present, without
posterior median projection. Deep bar (associated with knobs of anchors)
present. Parasites of external surface of species of Loricariidae (Siluriformes).
Type and only species: H. malmbergi BOEGER, KRITSKY & BELMONT-JÉGU,
1994 from Rhineloricaria sp (Figs. 3-7 A-D).
Nothogyrodactylus KRITSKY & BOEGER, 1991
Oviparous. Peduncle conspicuous. Copulatory organ composed of MCO,
accessory piece. Accessory piece one to three, non-articulated. MCOmuscu-
lar, elongate, lacking spines. Eggs in uterus never more than one. Ventral
anchor present. Cylindrical haptoral sclerite absent. Superficial bar present,
lacking a shield. Deep bar (associated with knobs of anchors) present.
Parasites of external surface of species of Loricariidae (Siluriformes).
N. amazonicus KRITSKY & BOEGER, 1991 from Ancistrus sp.
N. clavatus KRITSKY & BOEGER, 1991 from Ancistrus sp. (Type species).
N. plaesiophallus KRITSKY & BOEGER, 1991 from Ancistrus sp. (Figs. 3-8 A-E).
Oogyrodactylus HARRIS, 1983
Oviparous. Peduncle conspicuous. Copulatory organ composed only of
MCO, muscular, elongate, sac-like, lacking spines. Eggs in uterus never more
than one. Ventral anchor present. Cylindrical haptoral sclerite absent. Superfi-
cial bar present, lacking a shield. Deep bar (associated with knobs of anchors)
present. Parasites of external surface of species of Loricariidae (Siluriformes).
Type and only species: O. farlowellae HARRIS, 1983 from Farlowella amazona
(Figs. 3-9 A-D).
Phanerothecium KRITSKY & THATCHER, 1977
Oviparous. Peduncle conspicuous. Copulatory organ composed only of
MCO, muscular, sac-like, with or without spines. Eggs in uterus more than
2, usually up to 10. Ventral anchor present. Cylindrical haptoral sclerite
absent. Superficial bar present, lacking a shield. Deep bar (associated twith
knobs of anchors) present. Parasites of external surface of species of
Pimelodidae and Loricariidae (Siluriformes).
P. caballeroi KRITSKY & THATCHER, 1977 from Cephalosilurus zungaro (Pimelo-
didae) (Type species) (Fig. 3-10 A-E).
P. harrisi KRITSKY & BOEGER, 1991 from Plecostomus plecostomus (Loricariidae)
P. spinatus BOEGER, KRITSKY & BELMONT-JÉGU, 1994 from Hypostomus punctatus
(Loricariidae).
P. sp. (= P. caballeroi forma major of KRITSKY & THATCHER, 1977) from
Cephalosilurus zungaro (Pimelodidae).
Scleroductus JARA & CONE, 1989
Viviparous. Peduncle conspicuous. Copulatory organ composed only of
MCO, muscular, bulbous, with spines; one spine significantly longer, serving
as guide for distal vas deferens. Ventral anchor present. Cylindrical haptoral
64 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
sclerite absent. Superficial bar present, with double posterior projections
similar to ribbons. Deep bar (associated with knobs of anchors) present.
Parasites of gills and external surface of species of Siluriformes.
S. spp. (of KRITSKY, BOEGER & POPAZOGLO, 1995) from Glanidium melanopter-
um (Auchenipteridae), Pimelodella sp. (Pimelodidae), Parauchenipterus striatu-
lus (Auchenipteridae), Rhamdia quelen (Pimelodidae).
S. yuncensi JARA & CONE, 1989 from Pimelodella yuncensis (Pimelodidae) (Type
species) (Figs. 3-11 A-F).
Order Dactylogyrinea BYCHOWSKY, 1937
Suborder Dactylogyridea BYCHOWSKY, 1937
Diplectanidae MONTICELLI, 1903
Diplectanum DIESING, 1858
Body fusiform. Tegument scaled or smooth. Eyes four or two; accessory
granules present or absent. Pharynx bulbous, one subunit. Ceca non-
confluent. Gonads tandem; germarium anterior to testis, looping right
intestinal caecum. Testis single. Copulatory organ composed only of MCO, or
MCO and accessory piece. MCO J-shaped, or sinuous, or somewhat straight,
or slightly curved. Accessory piece one, when present, non-articulated.
Seminal vesicle fusiform. Prostatic reservoirs short, round to ovate. Germari-
um looping right caecum. Vagina sinistro-marginal, sclerotized or muscular.
Squamodisc present. Hooks dactylogyrid, with shank simple; 14, with ancyro-
cephaline distribution (4 dorsal, 10 ventral). Ventral, dorsal anchor pairs
present. Ventral anchor with point, shaft, roots well defined. Dorsal anchor
with shaft, point, base not clearly separated into roots. Ventral bar lip-shaped;
anterior projection absent, posterior projection present or absent. Groove on
entire length of ventral bar present. Dorsal bar present, double, rod-shaped.
Parasites of the gills of species of Perciformes (in Neotropical freshwater,
only species of Sciaenidae are known to host diplectanids).
D. decorum KRITSKY & THATCHER, 1984 from Plagioscion squamosissimus (Figs. 3-
12 A-F).
D. gymnopeus KRITSKY & THATCHER, 1984 from Plagioscion squamosissimus.
D. hilum KRITSKY & THATCHER, 1984 from Plagioscion sp.
D. pescadae KRITSKY & THATCHER, 1984 from Plagioscion sp., Plagioscion squamosis-
simus.
D. piscinarius KRITSKY & THATCHER, 1984 from Plagioscion squamosissimus.
Dactylogyridae BYCHOWSKY, 1933
Ameloblastella KRITSKY, MENDONZA-FRANCO & SCHOLZ, 2000
Synonyms: Cleidodiscus (in part); Vancleaveus (in part); Urocleidoides (in part)
Body fusiform. Tegument smooth; annulations on body absent. Eyes absent;
eye granules present. Pharynx bulbous, one subunit. Ceca confluent.
Gonads overlapping; testis single. Copulatory organ composed of MCO and
accessory piece. MCO of loose coils, not inflated proximally. Accessory
piece articulated to MCO by copulatory ligament. Seminal vesicle fusiform,
with thin walls, of variable length. Prostatic reservoirs short, round to ovate.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 65
Germarium ovate or elongate. Vagina sinistro-marginal, sclerotized; vaginal
bar, accessory vaginal sclerite absent. Hooks dactylogyrid, shank divided in
two portions clearly defined; 14, with ancyrocephaline distribution (4 dorsal,
10 ventral), not on peduncles; hook pair 2 on the haptor, close to hook pairs
3, 4; hook pair 5 similar to other pairs. Anchors ventral, dorsal pairs. Ventral
anchor with point, shaft, roots well defined; anchor filament delicate, often
inconspicuous; accessory sclerite associated with base of ventral anchor
absent. Dorsal anchor with shaft, point, base composed of two roots; fold
on inner superficial root of dorsal anchor absent. Ventral bar rod-shaped
with antero-median projection; no posterior median projection. Dorsal bar
single, rod-shaped; anterior, posterior projections absent. Parasites of the
gills of species of Pimelodidae (Siluriformes).
A. chavarriai (PRICE, 1938) from Rhamdia sebae, Rhamdia rogersi, Rhamdia quelen.
(Type species) (Figs. 3-13 A-E).
A. mamaevi (KRITSKY & THATCHER, 1976) from Cephalosilurus zungaro.
A. platensis (SURIANO & INCORVAIA, 1995) from Pimelodus claria maculatus.
Amphithecium BOEGER & KRITSKY, 1988
Body strongly flattened or fusiform. Tegument papillated, scaled, or smooth;
annulations on body absent. Eyes four or two; eyes granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece; MCO single or
double, somewhat straight or slightly curved rami. Accessory piece articulat-
ed to MCO directly or by copulatory ligament. Seminal vesicle fusiform with
thin walls. Prostatic reservoirs short, round to ovate. Germarium ovate or
elongate. Vagina sclerotized or muscular, double; vaginal apertures dorso-
lateral; vaginal bar, accessory vaginal sclerite absent. Hooks dactylogyrid,
shank divided in two portions clearly defined; 14, with ancyrocephaline
distribution (4 dorsal, 10 ventral), not on peduncles; hook pair 2 on haptor,
close to hook pairs 3, 4; hook pair 5 similar to other pairs. Ventral, dorsal
pairs of anchors. Ventral anchor with point, shaft, well defined roots; anchor
filament delicate, often inconspicuous. Dorsal anchor with shaft, point, base
composed of two roots; fold on inner superficial root absent. Ventral bar
present, slightly V-shaped, slightly U-shaped, or rod-shaped, anterior, poste-
rior projections absent. Dorsal bar slightly V-shaped, slightly U-shaped, or
rod-shaped, anterior, posterior projections absent. Parasites of the gills of
species of Serrasalmidae (Characiformes).
A. brachycirrum BOEGER & KRITSKY, 1988 from Pygocentrus nattereri.
A. calycinum BOEGER & KRITSKY, 1988 from Pygocentrus nattereri (Type species)
(Fig. 3-14 A-F).
A. camelum BOEGER & KRITSKY,1988 from Pygocentrus nattereri.
A. catalaoensis BOEGER & KRITSKY, 1988 from Pygocentrus nattereri.
A. diclonophallum KRITSKY, BOEGER & JÉGU, 1997 from Serrasalmus elongatus,
Serrasalmus sp., Pristobrycon sp., Serrasalmus compressus, Serrasalmus rhombeus,
Serrasalmus gouldingi.
66 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
A. falcatum BOEGER & KRITSKY, 1988 from Pygocentrus nattereri, Pristobrycon sp.,
Serrasalmus elongatus, Serrasalmus compressus, Serrasalmus gouldingi, Serrasalmus
manuelli, Serrasalmus rhombeus, Serrasalmus spilopleura, Serrasalmus sp.
A. junki BOEGER & KRITSKY, 1988 from Pygocentrus nattereri, Serrasalmus
rhombeus.
A. microphallum KRITSKY, BOEGER & JÉGU, 1997 from Pygocentrus nattereri,
Serrasalmus sp.
A. minutum KRITSKY, BOEGER & JÉGU, 1997 from Serrasalmus gouldingi, Pristobry-
con sp., Serrasalmus spilopleura, Pristobrycon eigenmanni (Type species).
A. muricatum KRITSKY, BOEGER & JÉGU, 1997 from Pristobrycon eigenmanni,
Serrasalmus rhombeus, Serrasalmus sp.
A. pretiosum KRITSKY, BOEGER & JÉGU, 1997 from Serrasalmus manueli, Serrasal-
mus gouldingi, Pristobrycon sp.
A. prodotum KRITSKY, BOEGER & JÉGU, 1997 from Catoprion mento, Pristobrycon
striolatus.
A. speirocamarotum KRITSKY, BOEGER & JÉGU, 1997 from Serrasalmus elongatus.
A. unguiculum KRITSKY, BOEGER & JÉGU, 1997 from Serrasalmus spilopleura.
A. verecundum KRITSKY, BOEGER & JÉGU, 1997 from Serrasalmus sp., Pristobrycon
eigenmanni.
Anacanthoroides KRITSKY & THATCHER, 1976
Body strongly flattened. Tegument smooth. Eyes four; eye granules
absent. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece. MCO coiled.
Accessory piece articulated to MCO by copulatory ligament. Seminal
vesicle fusiform. Germarium ovate, solid. Vagina sclerotized, sinistro-
marginal; vaginal bar, accessory vaginal sclerite absent. Hooks dactylogy-
rid, shank simple; 14 marginal; hook pair 2 on the haptor, close to hook
pairs 3, 4; hook pair 5 similar to other pairs. Two pairs of ventral anchors
modified as 4A hooks (incipient). Bars absent. Parasites from the gills of
species of Prochilodontidae (Characiformes).
Type and only species: A. mizellei KRITSKY & THATCHER, 1976 from
Prochilodus reticulatus (Fig. 3-15 A-C).
Anacanthorus MIZELLE & PRICE, 1965
Body fusiform. Tegument smooth. Eyes four or two; eye granules present or
absent. Pharynx bulbous, one subunit. Ceca confluent. Gonads tandem;
testis anterior to germarium. Copulatory organ composed of MCO, accesso-
ry piece; MCO J-shaped, sinuous, somewhat straight, slightly curved, or
coiled. Accessory piece one, non-articulated or articulated directly to MCO.
Seminal vesicle fusiform. Prostatic reservoirs round to short, ovate. Germa-
rium ovate or elongate; solid. Vagina absent. Hooks dactylogyrid, proximal
portion of shank inflated, divided in two portions clearly defined, or simple.
Hooks 14, with anacanthorine distribution (6 dorsal, 8 ventral). Ventral,
dorsal anchors pairs present modified as 4A hooks (incipient). Bars absent.
Parasites of the gills of species of Characiformes.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 67
A. acuminatus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus elongatus,
Triportheus angulatus, Triportheus albus (Characidae).
A. alatus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus albus, Triporth-
eus elongatus (Characidae).
A. amazonicus KRITSKY & BOEGER, 1995 from Serrasalmus rhombeus, Serrasalmus
sp., Pristobrycon striolatus (Curimatidae).
A. anacanthorus MIZELLE & PRICE, 1965 from Pygocentrus nattereri (Serrasalmi-
dae) (Type species).
A. andersoni KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angulatus
(Characidae).
A. beleophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Pristobrycon eigenman-
ni (Serrasalmidae).
A. bellus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus albus, Triporth-
eus elongatus (Characidae) (Figs. 3-17 A).
A. brazilensis MIZELLE & PRICE, 1965 from Pygocentrus nattereri (Serrasalmidae).
A. brevis MIZELLE & KRITSKY, 1969 from Brycon melanopterus (Characidae).
A. calophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus elongatus
(Characidae) (Fig. 3-17 B).
A. carinatus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angulatus
(Characidae) (Fig. 3-17 C).
A. catoprioni KRITSKY, BOEGER & VAN EVERY, 1992 from Catoprion mento
(Serrasalmidae).
A. chaunophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angula-
tus (Characidae).
A. chelophorus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angulatus,
Triportheus sp. (Characidae).
A. cinctus VAN EVERY & KRITSKY, 1992 from Pristobrycon striolatus (Serrasalmi-
dae).
A. cladophallus VAN EVERY & KRITSKY, 1992 from Serrasalmus spilopleura
(Serrasalmidae).
A. colombianus KRITSKY & THATCHER, 1974 from Salminus affinis (Characidae).
A. cornutus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angulatus
(Characidae) (Fig. 3-17 D).
A. crytocaulus VAN EVERY & KRITSKY, 1992 from Pristobrycon striolatus (Serras-
almidae).
A. cuticulovaginus KRITSKY & THATCHER, 1974 from Salminus affinis (Characidae).
A. dipelecinus KRITSKY, BOEGER & VAN EVERY, 1992 from Roeboides myersi
(Characidae) (Fig. 3-17 E).
A. elegans KRITSKY, THATCHER & KAYTON, 1979 from Brycon melanopterus
(Characidae).
A. euryphallus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus albus,
Triportheus elongatus, Triportheus angulatus (Characidae) (Fig. 3-17 H).
A. formosus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus elongatus,
Triportheus sp. (Characidae).
68 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
A. furculus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus elongatus
(Characidae) (Fig. 3-17 G).
A. glyptophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angulatus
(Characidae) (Fig. 3-17 F).
A. gravihamulatus VAN EVERY & KRITSKY, 1992 from Pristobrycon eigenmanni
Serrasalmus sp. 2, Serrasalmus rhombeus (Serrasalmidae).
A. hoplophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Myleus rubripinnis
(Serrasalmidae) (Fig. 3-17 I).
A. jegui VAN EVERY & KRITSKY, 1992 from Serrasalmus rhombeus, Serrasalmus
spilopleura, Pristobrycon sp., from Serrasalmus sp. 2, Pristobrycon eigenmanni,
Serrasalmus sp. (2n = 58) (Serrasalmidae).
A. kruidenieri KRITSKY, THATCHER & KAYTON, 1979 from Brycon melanopterus
(Characidae).
A. lasiophallus VAN EVERY & KRITSKY, 1992 from Pristobrycon striolatus (Serra-
salmidae).
A. lepyrophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Serrasalmus elongatus,
Serrasalmus sp. (2n = 58), Serrasalmus sp. 1 (Serrasalmidae).
A. lygophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angulatus
(Characidae) (Fig. 3-17 M).
A. maltai BOEGER & KRITSKY, 1988 from Pygocentrus nattereri (Serrasalmidae).
A. mastigophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Pristobrycon
eigenmanni (Serrasalmidae) (Fig. 3-17 J).
A. mesocondylus VAN EVERY & KRITSKY, 1992 from Serrasalmus spilopleura,
Pristobrycon eigenmanni, Serrasalmus elongatus, Serrasalmus sp. 1, Pristobrycon sp.
n., Serrasalmus sp. 2 (Serrasalmidae).
A. nanus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angulatus
(Characidae).
A. neotropicalis MIZELLE & PRICE, 1965 from Pygocentrus nattereri (Serrasalmidae).
A. palamophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Pristobrycon sp. n.
(Serrasalmidae).
A. paraspathulatus KRITSKY, BOEGER & VAN EVERY, 1992 from Mylossoma
duriventris (Serrasalmidae).
A. pedanophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Myleus rubripinnis
(Serrasalmidae).
A. pelorophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus elongatus
(Characidae) (Fig. 3-17 N).
A. penilabiatus BOEGER, HUSAK & MARTINS, 1995 from Piaractus mesopotamicus
(Serrasalmidae).
A. periphallus KRITSKY, BOEGER & VAN EVERY, 1992 from Serrasalmus sp. 1,
Serrasalmus sp. 2 (Serrasalmidae)(Fig. 3-17 L).
A. pithophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angulatus
(Characidae) (Fig. 3-17 K).
A. prodigiosus VAN EVERY & KRITSKY, 1992 from Serrasalmus sp., Serrasalmus
rhombeus, Serrasalmus elongatus (Serrasalmidae).
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 69
A. quinqueramis KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus albus,
Triportheus elongatus (Characidae).
A. ramosissimus VAN EVERY & KRITSKY, 1992 from Serrasalmus elongatus (Serra-
salmidae).
A. ramulosus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus albus,
Triportheus elongatus (Characidae).
A. reginae BOEGER & KRITSKY, 1988 from Pygocentrus nattereri (Serrasalmidae).
A. rondonensis BOEGER & KRITSKY, 1988 from Pygocentrus nattereri (Serrasalmidae).
A. scapanus VAN EVERY & KRITSKY, 1992 from Serrasalmus spilopleura (Serra-
salmidae).
A. sciponophallus VAN EVERY & KRITSKY, 1992 from Serrasalmus sp., Serrasalmus
elongatus, Serrasalmus rhombeus, Serrasalmus spilopleura (Serrasalmidae) (Figs.
3-16 A-E).
A. serrasalmi VAN EVERY & KRITSKY, 1992 from Pristobrycon sp. n., Serrasalmus
sp., Serrasalmus elongatus, Serrasalmus rhombeus, Serrasalmus spilopleura (Serra-
salmidae).
A. spathulatus KRITSKY, THATCHER & KAYTON, 1979 from Colossoma macropo-
mum, Colossoma bidens (Characidae).
A. spinatus KRITSKY, BOEGER & VAN EVERY, 1992 from Myleus rubripinnis
(Serrasalmidae) (Fig. 3-17 P).
A. spiralocirrus KRITSKY, THATCHER & KAYTON, 1979 from Brycon melanopterus
(Characidae).
A. stachophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Pygocentrus nattereri
(Serrasalmidae).
A. stagmophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Myleus rubripinnis
(Serrasalmidae).
A. strongylophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus
elongatus (Characidae).
A. thatcheri BOEGER & KRITSKY, 1988 from Pygocentrus nattereri (Serrasalmidae).
A. tricornis KRITSKY, BOEGER & VAN EVERY, 1992 from Triportheus angulatus,
Triportheus elongatus (Characidae).
A. xaniophallus KRITSKY, BOEGER & VAN EVERY, 1992 from Pristobrycon sp. n.,
Pristobrycon eigenmanni (Serrasalmidae) (Fig. 3-17 O).
Ancistrohaptor AGARWAL & KRITSKY, 1998
Body fusiform. Tegument smooth. Eyes four; eyes granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece. MCO
sclerotized, coiled. Accessory piece two, one non-articulated, one articulat-
ed to MCO. Seminal vesicle fusiform with thin walls. Prostatic reservoirs
unknown. Germarium ovate or elongate, solid. Vagina dextro-marginal or
ventro-dextral. Hooks dactylogyrid, shank divided in two portions clearly
defined, 14, with ancyrocephaline distribution (4 dorsal, 10 ventral).
Ventral, dorsal anchor pairs present. Ventral anchor with point, elongate
shaft, roots well defined; anchor filament delicate, often inconspicuous.
70 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
Dorsal anchor with shaft, point, base composed of two roots. Ventral bar
rod-shaped with anterior transversal groove, anterior, posterior projections
absent. Dorsal bar slightly V-shaped or rod-shaped; anterior, posterior
projections absent. Parasites of the gills of Triportheus spp. (Characidae,
Characiformes).
A. falcatum AGARWAL & KRITSKY, 1998 from Triportheus elongatus.
A. falciferum AGARWAL & KRITSKY, 1998 from Triportheus elongatus, Triportheus
angulatus, Triportheus albus Triportheus sp. (Type species) (Figs. 3-18 A-C).
A. falcunculum AGARWAL & KRITSKY, 1998 from Triportheus albus, Triportheus
elongatus, Triportheus angulatus.
Annulotrematoides KRITSKY & BOEGER, 1995
Body fusiform. Tegument smooth, annulations present. Eyes four; eyes
granules absent or present. Pharynx bulbous, one subunit. Ceca confluent.
Gonads overlapping. Copulatory organ composed of MCO, accessory
piece. MCO sclerotized, J-shaped. Accessory piece articulated to MCO by
copulatory ligament. Seminal vesicle fusiform. Prostatic reservoirs round
to short, ovate. Germarium ovate or elongate. Vagina sinistro-marginal,
sclerotized. Hooks dactylogyrid, shank divided in two portions clearly
defined; 14, with ancyrocephaline distribution (4 dorsal, 10 ventral).
Ventral, dorsal anchor pairs present. Ventral anchor with point, shaft, roots
well defined; anchor filament delicate, often inconspicuous. Dorsal anchor
with shaft, point, base composed of two roots. Ventral bar rod-shaped;
antero-median projection; posterior median projection absent. Dorsal bar
slightly V-shaped; anterior, posterior projections absent. Parasites of the
gills of species of Characiformes.
A. amazonicus KRITSKY & BOEGER, 1995 from Psectrogaster rutiloides (Curima-
tidae) (Type species) (Figs. 3-19 A-B).
A. bryconi CUGLIANNA, CORDEIRO & LUQUE, 2003 from Brycon cephalus
(Characidae).
Aphanoblastella KRITSKY, MENDONZA-FRANCO & SCHOLZ, 2000
Synonyms: Urocleidoides (in part); Cleidodiscus (in part)
Body fusiform. Tegument smooth. Eyes four; eyes granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads tandem;
germarium anterior to testis. Copulatory organ composed of MCO,
accessory piece, sinuous or coiled. Accessory piece one, non-articulated.
Seminal vesicle fusiform. Prostatic reservoirs round to short, ovate.
Germarium ovate or elongate. Vagina muscular, sinistro-marginal. Hooks
dactylogyrid, shank simple; 14, with ancyrocephaline distribution (4 dorsal,
10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor with point,
shaft, roots well defined; anchor filament delicate, often inconspicuous.
Dorsal anchor with shaft, point, base composed of two roots. Ventral bar
slightly V-shaped, anterior projection absent; posterior projections present.
Dorsal bar slightly V-shaped; anterior, posterior projections absent. Para-
sites of the gills of species of Pimelodidae (Siluriformes).
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 71
A. mastigatus SURIANO, 1986 from Rhamdia sapo.
A. robustus (MIZELLE & KRITSKY, 1969) from Rhamdia sp.
A. travassosi (PRICE, 1938) from Rhamdia rogersi, Rhamdia sebae, Pimelodella
laticeps, Rhamdia quelen (Type species) (Figs. 3-20 A-D).
Cacatuocotyle BOEGER, DOMINGUES & KRITSKY, 1997
Body robust, strongly flattened dorso-ventrally. Tegument smooth. Eyes
four; eyes granules present. Pharynx bulbous, one subunit. Ceca confluent.
Gonads tandem; germarium anterior to testis. Copulatory organ com-
posed of MCO, accessory piece. MCO coiled. Accessory piece articulated
to MCO by copulatory ligament. Seminal vesicle C-shaped or fusiform.
Prostatic reservoirs round to short, ovate. Germarium ovate or elongate.
Vagina sinistro-marginal, sclerotized. Anterior margins of haptor heavily
muscular. Hooks dactylogyrid with shank simple; 14, 12 ventral, on
posterior margin of haptor, 2 central. Ventral pair of anchors with point,
shaft, roots well defined. Dorsal anchor pair absent. Ventral bar rod-
shaped; anterior, posterior projections absent. Dorsal bar absent. Parasites
of gills of species of Characidae (Characiformes).
Type and only species: C. paranaensis BOEGER, DOMINGUES & KRITSKY, 1997
from Characidium pterostictum, Characidium lanei (Figs. 3-21 A-B).
Calpidothecioides KRITSKY, BOEGER & JÉGU, 1997
Synonyms: Urocleidus (in part).
Body fusiform. Tegument smooth. Eyes two; eye granules absent, present.
Pharynx bulbous, one subunit. Ceca confluent. Gonads overlapping.
Copulatory organ composed of MCO, accessory piece. MCO J-shaped,
somewhat straight, or slightly curved. Accessory piece articulated directly
to MCO or articulated to MCO by copulatory ligament. Seminal vesicle C-
shaped or fusiform. Germarium ovate or elongate. Vagina double, muscu-
lar, openings one marginal, one dorsal. Hooks dactylogyrid with shank
divided in two portions clearly defined; 14, with ancyrocephaline distribu-
tion (4 dorsal, 10 ventral). Ventral, dorsal anchorpairs present. Ventral
anchor with point, shaft, roots well defined. Dorsal anchor with shaft,
point, base composed of two roots. Ventral bar rod-shaped, with slightly
projected margin, with or without medial cleft; posterior projection absent.
Dorsal bar slightly V-shaped; anterior, posterior projections absent. Para-
sites of the gills of species of Serrasalmidae (Characiformes).
C. orthus (MIZELLE & PRICE, 1965) KRITSKY, BOEGER & KRITSKY, 1997 from
Pygocentrus nattereri.
C. pygopristi KRITSKY, BOEGER & JÉGU, 1997 from Pygopristis denticulata (Type
species) (Figs. 3-22 A-B).
Calpidothecium KRITSKY, BOEGER & JÉGU, 1997
Synonyms: Urocleidus (in part); Cleidodiscus (in part).
Body fusiform. Tegument smooth; annulations on body absent or present.
Eyes two; eye granules absent. Pharynx bulbous, one subunit. Ceca
confluent. Gonads overlapping. Copulatory organ composed of MCO,
72 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
accessory piece. MCO straight or slightly curved. Accessory piece articu-
lated to MCO by copulatory ligament. Seminal vesicle fusiform. Prostatic
reservoirs round to short, ovate. Germarium ovate or elongate. Vagina
sinistro-marginal, sclerotized. Hooks dactylogyrid with shank divided in
two portions clearly defined; 14, with ancyrocephaline distribution (4
dorsal, 10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor
with point, shaft, roots well defined. Dorsal anchor with shaft, point, base
composed of two roots. Ventral bar slightly V-shaped or rod-shaped;
anterior, posterior projections absent. Dorsal bar V-shaped; anterior,
posterior projections absent. Parasites of the gills of species of Serrasalm-
idae (Characiformes).
C. crescentis (MIZELLE & PRICE, 1965) KRITSKY, BOEGER & JÉGU, 1997 from
Pygocentrus nattereri, Pygopristis denticulata (Type species) (Figs. 3-23 A-C).
C. serrasalmus (MIZELLE & PRICE, 1965) KRITSKY, BOEGER & JÉGU, 1997 from
Pygopristis denticulata, Pygocentrus nattereri.
Cosmetocleithrum KRITSKY, THATCHER & BOEGER, 1986
Body fusiform. Tegument smooth. Eyes absent; eyes granules present.
Pharynx bulbous, one subunit. Ceca confluent. Gonads tandem; germari-
um anterior to testis. Copulatory organ composed of MCO, accessory
piece. MCO J-shaped or coiled. Accessory piece one, non-articulated.
Seminal vesicle fusiform. Prostatic reservoirs round to short, ovate.
Germarium ovate or elongate. Vagina sinistro-marginal or sinistro-ventral,
sclerotized. Hooks dactylogyrid with shank simple; 14, with ancyrocepha-
line distribution (4 dorsal, 10 ventral). Ventral, dorsal anchor pairs present.
Ventral anchor with point, shaft, roots well defined. Dorsal anchor with
shaft, point, base composed of two roots. Ventral bar slightly V-shaped,
slightly U-shaped, or strongly V-shaped, anterior projection absent, poste-
rior projections present or absent. Dorsal bar slightly V-shaped, slightly U-
shaped, strongly V-shaped, or rod-shaped; anterior projection absent,
posterior projections on dorsal bar two, ribbon-like. Parasites of species of
Siluriformes, especially species of Doradidae.
C. bulbocirrus KRITSKY, THATCHER & BOEGER, 1986 from Pterodoras granulosus
(Doradidae).
C. confusus KRITSKY, THATCHER & BOEGER, 1986 from Oxydoras niger (Doradidae).
C. gussevi KRITSKY, THATCHER & BOEGER, 1986 from Oxydoras niger (Doradidae)
(Figs. 3-24 A-F).
C. longivaginatum SURIANO & INCORVAIA, 1995 from Pimelodus albicans (Pimelo-
didae).
C. parvum KRITSKY, THATCHER & BOEGER, 1986 from Oxydoras niger (Dora-
didae).
C. rarum KRITSKY, THATCHER & BOEGER, 1986 from Oxydoras niger (Dora-
didae).
C. sobrinus KRITSKY, THATCHER & BOEGER, 1986 from Oxydoras niger (Dora-
didae).
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 73
Curvianchoratus HANEK, MOLNAR & FERNANDO, 1974
Synonym: Notodiplocerus SURIANO, 1980
Body short, robust, strongly flattened. Tegument smooth. Eyes four; eye
granules absent or present. Pharynx bulbous, one subunit. Ceca confluent.
Gonads tandem; germarium anterior to testis. Copulatory organ com-
posed of MCO, accessory piece. MCO J-shaped or coiled. Accessory piece
articulated directly to MCO. Seminal vesicle fusiform. Prostatic reservoirs
unknown. Germarium ovate or elongate. Vagina dextro-marginal, sclero-
tized. Hooks dactylogyrid with shank simple; 14, with ancyrocephaline
distribution (4 dorsal, 10 ventral). Ventral, dorsal anchor pairs. Ventral
anchor with point, shaft, roots well defined. Dorsal anchor greatly
modified, base apparently elongate, distorted, distal extremity sometimes
hook-like. Ventral bar strongly V-shaped; anterior, posterior projections
absent. Dorsal bar double, strongly distorted. Parasites of the gills of
species of Curimatidae (Characiformes).
C. hexacleidus HANEK, MOLNAR & FERNANDO, 1974 from Curimata argentea.
C. singularis (SURIANO,1980) from Pseudocurimata gilberti (Figs. 3-25 A-C).
Dawestrema PRICE & NOWLIN, 1967
Body fusiform. Tegument smooth. Eyes four; eyes granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads tandem;
germarium anterior to testis. Copulatory organ composed of MCO and
accessory piece. MCO coiled. Accessory piece articulated directly to MCO.
Seminal vesicle two, fusiform. Prostatic reservoirs round to short, ovate.
Germarium ovate or elongate. Vagina sinistro-marginal, sclerotized.
Hooks dactylogyrid, with shank divided in two portions clearly defined;
14, arranged concentrically around haptor dorso-ventrally. Ventral, dorsal
anchor pairs. Ventral anchor with point, shaft, roots well defined. Dorsal
anchor dactylogyrid, with shaft, point, base composed of two roots.
Ventral bar present rod-shaped, antero-median projection present, posteri-
or projection absent. Dorsal bar slightly U-shaped; anterior, posterior
projections absent. Parasites of the gills of species of Arapaima gigas,
Osteoglossidae (Osteoglossiformes).
D. cycloancistrioides KRITSKY, BOEGER & THATCHER, 1985 from Arapaima gigas.
D. cycloancistrium PRICE & NOWLIN, 1967 from Arapaima gigas (Type species)
(Figs. 3-26 A-C).
D. punctatum PRICE & NOWLIN, 1967 from Arapaima gigas.
Demidospermus SURIANO, 1983
Synonyms: Omothecium KRITSKY, THATCHER & BOEGER, 1987; Paramphoclei-
thrum SURIANO & INCORVAIA, 1995.
Body fusiform. Tegument smooth. Eyes four or two; eye granules absent
or present. Pharynx bulbous, one subunit. Ceca confluent. Gonads
tandem; germarium anterior to testis. Copulatory organ composed of
MCO, accessory piece. MCO J-shaped, somewhat straight, slightly curved,
coiled. Accessory piece one, non-articulated or articulated directly to
74 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
MCO. Seminal vesicle fusiform. Prostatic reservoirs round to short, ovate.
Germarium ovate or elongate. Vagina sinistro-marginal, sclerotized or
muscular. Hooks dactylogyrid, entire shank inflated, conferring a robust
morphology to hook, or proximal portion of shank inflated (circular,
ovate), or shank divided in two portions clearly defined, or shank simple;
14, with ancyrocephaline distribution (4 dorsal, 10 ventral). Ventral, dorsal
anchor pairs present. Ventral anchor with point, shaft, roots not defined or
well defined. Dorsal anchor with shaft, point, base not clearly separated in
roots or base composed of two roots. Ventral bar strongly V-shaped;
anterior, posterior projection absent. Dorsal bar strongly V-shaped; anteri-
or projection absent; posterior projection present. Parasites of the gills of
species of Siluriformes, especially of Pimelodidae.
D. anus SURIANO, 1983 from Loricaria anus (Loricariidae). (Type species).
D. armostus KRITSKY & GUTIÉRREZ, 1998 from Pimelodus albicans, Pimelodus
clarias (Pimelodidae).
D. bidiverticulatum (SURIANO & INCORAVIA, 1995) from Pimelodus clarias, Pimelodus
albicans, Pimelodus clarias maculatus (Pimelodidae).
D. cornicinus KRITSKY & GUTIÉRREZ, 1998 fromIheringichthys westermanni
(Pimelodidae) (Figs. 3-27 A-F).
D. idolus KRITSKY & GUTIÉRREZ, 1998 from Pimelodus albicans (Pimelodidae).
D. labrosi FRANÇA, ISSAC, PAVANELLI & TAKEMOTO, 2003 from Iheringinchthys
labrosus (Pimelodidae).
D. leptosynophallus KRITSKY & GUTIÉRREZ, 1998 from Iheringichthys westermanni
(Pimelodidae).
D. luckyi (KRITSKY, THATCHER & BOEGER, 1987) from Pinirampus pirinampu
(Pimelodidae).
D. majusculus KRITSKY & GUTIÉRREZ, 1998 from Pimelodus albicans (Pimelodidae).
D. mandi FRANÇA, ISSAC, PAVANELLI & TAKEMOTO, 2003 from Iheringinchthys
labrosus (Pimelodidae).
D. paravalenciennesi GUTIERREZ & SURIANO, 1992 from Pimelodus clarias (Pimelo-
didae).
D. pinirampi (KRITSKY, THATCHER & BOEGER, 1987) from Pirinampus pirinampu
(Pimelodidae).
D. uncusvalidus GUTIERREZ & SURIANO, 1992 from Pimelodus clarias, Paraucheni-
pterus galeatus (Auchenipteridae).
D. valenciennesi GUTIERREZ & SURIANO, 1992 from Parapimelodus valenciennesi
(Pimelodidae).
Diaphorocleidus JOGUNOORI, KRITSKY & VENKATANARASAIAH, 2004
Synonym: Urocleidoides sensu lato (in part)
Body fusiform. Tegument smooth. Eyes four; eyes granules absent, or
present. Ceca confluent. Gonads overlapping. Copulatory organ com-
posed of MCO and accessory piece. MCO with loose coils, not inflated
proximally. Accessory piece one, non-articulated. Seminal vesicle fusiform.
Prostatic reservoirs round to short, ovate. Germarium ovate or elongate;
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 75
solid. Vagina sclerotized, single, sinistro-ventral. Vaginal bar, accessory
vaginal sclerite absent. Hooks dactylogyrid; shank divided in two portions
clearly defined; 14, with ancyrocephaline distribution (4 dorsal, 10 ventral).
Ventral, dorsal anchor pairs present. Ventral anchor with point, shaft, roots
well defined. Dorsal anchor with shaft, point, base composed of two roots.
Ventral bar slightly V-shaped, with antero-median projection. Dorsal bar
slightly V-shaped; anterior, posterior projections absent. Parasites of the
gills of species of Characidae (Characiformes).
D. affinis (MIZELLE, KRITSKY & CRANE, 1968) from Creatochanes affinis
D. armillatus JOGUNOORI, KRITSKY & VENKATANARASAIAH, 2004 from Gymnoc-
orymbus ternetzi (Type species) (Figs. 3-28 A-C).
D. kabatai (MOLNAR, HANEK & FERNANDO, 1974) from Astyanax fasciatus.
D. microstomus (MIZELLE, KRITSKY & CRANE, 1968) from Hemigrammus microsto-
mus.
Enallothecium KRITSKY, BOEGER & JÉGU, 1998
Synonym: Notothecium (in part).
Body short, robust, or fusiform. Tegument scaled or smooth. Eyes four or
two; eyes granules absent or present. Ceca confluent. Gonads overlapping.
Copulatory organ composed of MCO, accessory piece. MCO straight or
slightly curved. Accessory piece articulated to MCO by copulatory
ligament. Seminal vesicle C-shaped. Prostatic reservoirs round to short,
ovate. Germarium ovate or elongate. Vagina sinistro-dorsal, muscular.
Hooks dactylogyrid, shank divided in two portions clearly defined; 14,
with ancyrocephaline distribution (4 dorsal, 10 ventral). Ventral, dorsal
anchor pairs present. Ventral anchor with point, shaft, roots well defined.
Dorsal anchor with shaft, point, base composed of two roots. Ventral bar
slightly U-shaped; anterior, posterior projections absent. Dorsal bar
slightly U-shaped; anterior, posterior projections absent. Parasites of the
gills of species of Serrasalmidae (Characiformes).
E. aegidatum (BOEGER & KRITSKY, 1988) from Serrasalmus spilopleura, Serrasalmus
sp., Serrasalmus rhombeus, Serrasalmus compressus, Serrasalmus gouldingi, Serra-
salmus elongatus, Pristobrycon sp., Pygocentrus nattereri, Serrasalmus sp. (Type
species) (Fig. 3-29).
E. cornutum KRITSKY, BOEGER & JÉGU, 1998 from Serrasalmus gouldingi, Pristobry-
con eigenmanni, Serrasalmus sp., Serrasalmus sp., Pristobrycon sp., Serrasalmus
rhombeus, Serrasalmus compressus.
E. umbelliferum KRITSKY, BOEGER & JÉGU, 1998 from Serrasalmus compressus,
Serrasalmus rhombeus, Serrasalmus sp.
E. variabilum KRITSKY, BOEGER & JÉGU, 1998 from Pristobrycon striolatus.
Euryhaliotrema BOEGER & KRITSKY, 2002
Body fusiform. Tegument smooth. Eyes four; eye granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads tandem;
germarium anterior to testis. Copulatory organ composed of MCO, accesso-
ry piece. MCO sinuous, or somewhat straight, or slightly curved, or coiled,
76 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
with inflated proximal portion. Seminal vesicle fusiform. Prostatic reservoirs
round to short, ovate. Germarium ovate or elongate. Vagina dextro-
marginal, sclerotized. Hooks dactylogyrid, shank simple; 14, with ancyro-
cephaline distribution (4 dorsal, 10 ventral). Ventral anchor pair present;
dorsal anchor pairs present or absent. Ventral anchor with point, shaft, roots
well defined. Dorsal anchor with shaft, point, base composed of two roots.
Ventral bar slightly U-shaped, or rod-shaped, with short anterior sclerotized
muscle-attachment; posterior projection absent or shield like. Dorsal bar
present or absent, slightly U-shaped or rod-shaped; anterior projection
absent; posterior projection absent or shield like. Parasites of freshwater and
marine species of species of Sciaenidae (Perciformes).
E. chaoi KRITSKY & BOEGER, 2002 from Plagioscion squamosissimus (Type species)
(Figs. 3-30 A-B).
E. dontykoleos FEHLAUER & BOEGER, 2005 from Pachyurus junki
E. lovejoyi KRITSKY & BOEGER, 2002 from Plagioscion squamosissimus.
E. monacanthus KRITSKY & BOEGER, 2002 from Plagioscion squamosissimus.
E. potamocetes KRITSKY & BOEGER, 2002 from Plagioscion squamosissimus.
E. succedaneus KRITSKY & BOEGER, 2002 from Plagioscion squamosissimus.
E. thatcheri KRITSKY & BOEGER, 2002 from Plagioscion squamosissimus.
Gonocleithrum KRITSKY & THATCHER, 1983
Body fusiform. Tegument smooth. Eyes four; eye granules absent, or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping, or tandem; germarium anterior to testis. Copulatory organ composed
of MCO, accessory piece. Accessory piece articulated directly to MCO.
Seminal vesicle fusiform. Prostatic reservoirs round to short, ovate.
Germarium ovate or elongate. Vagina sinistro-marginal, sclerotized or
muscular; gonadal bar present. Hooks dactylogyrid, shank divided in two
portions clearly defined; 14, with ancyrocephaline distribution (4 dorsal,
10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor with point,
shaft, roots well defined. Dorsal anchor with shaft, point, base composed
of two roots. Ventral bar slightly U-shaped; anterior projection present or
absent, posterior projection absent. Dorsal bar slightly U-shaped, or
strongly V-shaped, or rod-shaped; anterior, posterior projections absent.
Parasites of the gills of species of Osteoglossum (Osteoglossidae, Osteoglo-
ssiformes) – presently only known from Osteoglossum biccirhosum.
G. aruanae KRITSKY & THATCHER, 1983.
G. coenoideum KRITSKY & THATCHER, 1983.
G. cursitans KRITSKY & THATCHER, 1983.
G. planacroideum KRITSKY & THATCHER, 1983.
G. planacrus KRITSKY & THATCHER, 1983 (Type species) (Figs. 3-31 A-D).
Gussevia KOHN & PAPERNA, 1964
Synonym: Longihaptor MIZELLE & KRITSKY, 1969
Body robust, strongly flattened, or fusiform. Tegument smooth. Eyes four;
eye granules absent or present. Pharynx bulbous, one subunit. Ceca
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 77
confluent. Gonads overlapping. Copulatory organ composed of MCO and
accessory piece. MCO coiled. Accessory piece one, non-articulated, or
articulated directly to MCO. Seminal vesicle fusiform. Prostatic reservoirs
round to short, ovate. Germarium ovate or elongate. Vagina ventral, or
dextro-marginal, or sinistro-marginal, sclerotized or muscular. Hooks dacty-
logyrid, proximal portion of shank inflated (circular, ovate), or shank simple;
14, with ancyrocephaline distribution (4dorsal, 10 ventral); hook pair 5
morphologically distinct from other pairs. Ventral, dorsal anchor pairs
present. Ventral anchor with point, shaft, roots defined or not well defined.
Dorsal anchor with shaft, point, base composed of two roots. Ventral bar
slightly U-shaped, or rod-shaped; anterior margin smooth or with slightly
projected, with or without medial cleft, or with anterior transversal groove;
posterior projection absent. Dorsal bar rod-shaped; anterior, posterior
projection absent. Parasites of Cichlidae (Perciformes).
G. alii (MOLNAR, HANEK & FERNANDO, 1974) from Cichlasoma bimaculatum.
G. alioides KRITSKY, THATCHER & BOEGER, 1986 from Cichlasoma severum.
G. arilla KRITSKY, THATCHER & BOEGER, 1986 from Cichla ocellaris.
G. asota KRITSKY, THATCHER & BOEGER, 1989 from Astronotus ocellatus (Figs. 3-
32 A-D).
G. astronoti KRITSKY, THATCHER & BOEGER, 1989 from Astronotus ocellatus.
G. cichlasomatis (MOLNAR, HANEK & FERNANDO, 1974) from Cichlasoma bimacu-
latum.
G. dispar KRITSKY, THATCHER & BOEGER, 1986 from Cichlasoma severum.
G. disparoides KRITSKY, THATCHER & BOEGER, 1986 from Cichlasoma severum.
G. dobosi (MOLNAR, HANEK & FERNANDO, 1974) from Cichlasoma bimaculatum.
G. elephus KRITSKY, THATCHER & BOEGER, 1986 from Uaru amphiacanthoides.
G. herotilapiae VIDAL-MARTÍNEZ, SCHOLZ & AGUIRRE-MACEDO, 2001 from Hero-
tilapia multispinosa.
G. longihaptor (MIZELLE & KRITSKY, 1969) from Cichla ocellaris.
G. obtusa KRITSKY, THATCHER & BOEGER, 1986 from Uaru amphiacanthoides.
G. rogersi KRITSKY, THATCHER & BOEGER, 1989 from Astronotus ocellatus.
G. spiralocirra KOHN & PAPERNA, 1964 from Pterophyllum scalare (Type species).
G. tucunarense KRITSKY, THATCHER & BOEGER, 1986 from Cichla ocellaris.
G. undulata KRITSKY, THATCHER & BOEGER, 1986 from Cichla ocellaris.
Heterothecium KRITSKY, BOEGER & JÉGU, 1997
Body fusiform. Tegument smooth; annulations on body present or absent.
Eyes four; eyes granules absent or present. Pharynx bulbous, one subunit.
Ceca confluent. Gonads overlapping. Copulatory organ composed of
MCO, accessory piece. MCO straight or slightly curved. Accessory piece
articulated to MCO by copulatory ligament. Seminal vesicle fusiform.
Prostatic reservoirs round to short, ovate. Germarium ovate or elongate.
Vagina sinistro-dorsal, muscular. Hooks dactylogyrid, shank divided in two
portions clearly defined; 14, with ancyrocephaline distribution (4 dorsal,
10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor with point,
78 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
shaft, roots well defined. Dorsal anchor with shaft, point, base composed
of two roots. Ventral bar rod-shaped; anterior, posterior projections
absent. Dorsal bar slightly U-shaped; anterior, posterior projections
absent. Parasites of species of Serrasalmidae (Characiformes).
H. dicrophallum KRITSKY, BOEGER & JÉGU, 1997 from Catoprion mento.
H. globatum KRITSKY, BOEGER & JÉGU, 1997 from Serrasalmus gouldingi (Type
species) (Fig. 3-33).
Heterotylus JOGUNOORI, KRITSKY & VENKATANARASAIAH, 2004
Body fusiform. Tegument smooth. Eyes absent; eye granules present or
absent. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece. MCO
straight or slightly curved. Accessory piece one, non-articulated. Seminal
vesicle fusiform. Prostatic reservoirs round to short, ovate. Germarium
ovate or elongate. Vagina ventral, sclerotized. Hooks dactylogyrid, shank
simple; 14, with ancyrocephaline distribution (4 dorsal, 10 ventral).
Ventral, dorsal anchor pairs present. Ventral anchor with point, shaft, roots
not defined. Dorsal anchor, with shaft, point, base composed of two roots.
Ventral bar inverted U-shaped, with tapering extremities; anterior, posteri-
or projections absent. Dorsal bar slightly U-shaped; anterior, posterior
projections absent. Parasites of species of Loricariidae (Siluriformes).
Type and only species: H. heterotylus JOGUNOORI, KRITSKY & VENKATANARA-
SAIAH, 2004 from Hypostomus sp. (Figs. 3-34 A-D).
Jainus MIZELLE, KRITSKY & CRANE, 1968
Body short, robust, or fusiform. Tegument smooth. Eyes four; eye
granules absent or present. Pharynx bulbous, one subunit. Ceca confluent.
Gonads overlapping. Copulatory organ composed of MCO, accessory
piece. MCO J-shaped, or sinuous, or coiled. Accessory piece one, non-
articulated. Seminal vesicle fusiform. Prostatic reservoirs round to short,
ovate. Germarium ovate or elongate. Vagina ventral, or sinistro-ventral,
sclerotized. Hooks dactylogyrid; 14, with ancyrocephaline distribution (4
dorsal, 10 ventral); hook pair 5 similar to other pairs, or significantly
distinct from others, reduced. Ventral, dorsal anchor pairs present. Ventral
anchor robust, with elongate superficial, deep roots. Dorsal anchor with
shaft, point, base composed of two roots. Ventral bar rod-shaped; antero-
median projection present or absent; posterior median projection present.
Dorsal bar slightly U-shaped, or strongly V-shaped, or rod-shaped;
anterior, posterior projections absent. Parasites of gills of species of
Characidae (Characiformes).
 J. amazonensis KRITSKY, THATCHER & KAYTON, 1980 from Brycon melanopterus.
 J. hexops KRITSKY & LEIBY, 1972 from Astyanax fasciatus.
 J. jainus MIZELLE, KRITSKY & CRANE, 1968 from Chalceus macrolepidotus (Type
species) (Figs. 3-35 A-D).
 J. robustus MIZELLE, KRITSKY & CRANE, 1968 from Creatochanes affinis.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 79
Kritskyia KOHN, 1990
Body fusiform. Tegument smooth. Eyes four; eye granules present or
absent. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece. MCO coiled.
Accessory piece more than two, non-articulated, or one, non-articulated to
MCO. Seminal vesicle fusiform. Prostatic reservoirs round to short, ovate.
Germarium ovate or elongate. Vagina sinistro-marginal or sinistro-ventral.
Hooks dactylogyrid with shank divided in two portions clearly defined; 14
on posterior margin of haptor. Ventral, dorsal anchors and bars absent.
Parasites of the excretory system of species of Characiformes and
Siluriformes.
K. annakohnnae BOEGER, TANAKA & PAVANELLI, 2001 from Serrasalmus spilopleu-
ra, Serrasalmus marginatus (Serrasalmidae, Characiformes).
K. boegeri TAKEMOTO, LIZAMA & PAVANELLI, 2002 from Prochilodus lineatus
(Prochilodontidae, Characiformes).
K. eirasi GUIDELLI, TAKEMOTO & PAVANELLI, 2003 from Leporinus lacustris
(Anostomidae, Characiformes).
K. moraveci KOHN, 1990 from Rhamdia quelen (Pimelodidae, Siluriformes)
(Type species) (Figs. 3-36 A-C).
Linguadactyloides THATCHER & KRITSKY, 1983
Body fusiform. Tegument smooth. Eyes four; eye granules absent or
present. Pharynx two bulbous subunits. Ceca confluent. Gonads tandem;
testes anterior to germarium. Testis multiple, pre-germarian.. Copulatory
organ composed of MCO, accessory piece. MCO coiled. Accessory piece
articulated to MCO by copulatory ligament. Seminal vesicle fusiform.
Prostatic reservoirs very long, often looping posteriorly. Germarium ovate
or elongate. Vagina dextro-marginal, sclerotized. Hooks dactylogyrid with
entire shank inflated, conferring a robust morphology to hook, or shank
simple; 14, with ancyrocephaline distribution (4 dorsal, 10 ventral).
Ventral, dorsal anchor pairs present. Ventral anchor short robust, deep
root longer than superficial root. Dorsal anchor robust, deep root longer
than superficial root. Ventral bar rod-shaped; anterior projection absent;
posterior projection present. Dorsal bar absent. Parasites of the gills of
species of Serrasalmidae (Characiformes).
Type and only species: L. brinkmanni THATCHER & KRITSKY, 1983 from
Colossoma macropomum (Figs. 3-37 A-D)
Monocleithrium PRICE & MCMAHON, 1966
Body fusiform. Tegument smooth. Eyes four; eye granules absent or present.
Pharynx bulbous, one subunit.Ceca confluent. Gonads tandem; germarium
anterior to testis. Copulatory organ composed of MCO, accessory piece.
MCO coiled. Accessory piece articulated directly to MCO. Seminal vesicle
unknown. Prostatic reservoirs unknown. Germarium ovate or elongate.
Vagina ventral. Hooks dactylogyrid, with shank divided in two portions clearly
defined; 14, with ancyrocephaline distribution (4 dorsal, 10 ventral). Ventral,
80 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
dorsal anchor pairs present. Ventral anchor with point, shaft, roots well
defined. Dorsal anchor with shaft, point, base composed of two roots. Ventral
bar rod-shaped; anterior, posterior projections absent. Dorsal bar absent.
Parasites of the gill of species of Hemiodontidae (Characiformes).
Type and only species: M. lavergneae PRICE & MCMAHON, 1966 from
Hemiodus semitaeniatus (Fig. 3-38).
Mymarothecium KRITSKY, BOEGER & JÉGU, 1996
Body fusiform. Tegument smooth. Eyes four; eye granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece. MCO
straight or slightly curved. Accessory piece articulated directly to MCO, or
articulated to MCO by copulatory ligament. Seminal vesicle fusiform.
Prostatic reservoirs short, round to ovate. Germarium ovate or elongate.
Vagina dextro-dorsal, muscular. Hooks dactylogyrid, shank divided in two
portions clearly defined; 14, with ancyrocephaline distribution (4 dorsal,
10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor with point,
shaft, roots well defined. Dorsal anchor with shaft, point, base composed
of two roots. Ventral bar rod-shaped; anterior, posterior projections
present or absent. Dorsal bar slightly U-shaped or rod-shaped; anterior
projection present or absent, posterior projection absent. Parasites of gills
of species of Serrasalmidae (Characiformes).
M.boegeri COHEN & KOHN, 2005 from Colossoma macropomum (Characiformes,
Characidae).
M.dactylotum KRITSKY, BOEGER & JÉGU, 1996 from Serrasalmus sp. (2n = 58),
Serrasalmus sp. (2 of Jégu), Pristobrycon sp., Serrasalmus rhombeus (Type
species) (Figs. 3-39 A-C).
M.galeolum KRITSKY, BOEGER & JÉGU, 1996 from Pristobrycon eigenmanni,
Serrasalmus gouldingi, Pygocentrus nattereri, Pristobrycon sp., Serrasalmus rhombeus.
M.perplanum KRITSKY, BOEGER & JÉGU, 1996 from Serrasalmus spilopleura.
M.viatorum BOEGER, PIASECKI & SOBECKA, 2002 from Piaractus brachypomus.
M.whittingtoni KRITSKY, BOEGER & JÉGU, 1996 from Serrasalmus rhombeus, from
Serrasalmus sp. (2n = 58).
Notothecium BOEGER & KRITSKY, 1988
Body fusiform. Tegument smooth. Eyes absent; eye granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece. MCO single, or
double, sclerotized, J-shaped, or straight or slightly curved. Accessory piece
articulated to MCO by copulatory ligament. Seminal vesicle C-shaped.
Prostatic reservoirs round to short, ovate. Germarium ovate or elongate.
Vagina dextro-dorsal, muscular. Hooks dactylogyrid, shank divided in two
portions clearly defined; 14, with ancyrocephaline distribution (4 dorsal, 10
ventral). Ventral, dorsal anchor pairs present. Ventral anchor with point,
shaft, roots well defined. Dorsal anchor with shaft, point, base composed of
two roots. Ventral bar slightly U-shaped or rod-shaped; anterior, posterior
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 81
projections absent. Dorsal bar strongly V-shaped; anterior, posterior projec-
tions absent. Parasites of gills of species of Serrasalmidae (Characiformes).
N. circellum KRITSKY, BOEGER & JÉGU, 1998 from Serrasalmus gouldingi, Pristobry-
con sp.
N. cyphophallum KRITSKY, BOEGER & JÉGU, 1998 from Serrasalmus rhombeus,
Pristobrycon eigenmanni, Serrasalmus compressus, Serrasalmus elongatus, Serrasalmus
gouldingi, Serrasalmus sp.
N. deleastoideum KRITSKY, BOEGER & JÉGU, 1998 from Serrasalmus sp.
N. deleastum KRITSKY, BOEGER & JÉGU, 1998 from Serrasalmus elongatus, Serrasal-
mus rhombeus, Serrasalmus gouldingi, Serrasalmus sp.
N. mizellei BOEGER & KRITSKY, 1988 from Pygocentrus nattereri (Type species)
(Figs. 3-40 A-B).
N. modestum KRITSKY, BOEGER & JÉGU, 1998 from Serrasalmus spilopleura.
N. phyleticum KRITSKY, BOEGER & JÉGU, 1998 from Serrasalmus rhombeus.
N. reduvium KRITSKY, BOEGER & JÉGU, 1998 from Serrasalmus sp.
Notothecioides KRITSKY, BOEGER & JÉGU, 1997
Body fusiform. Tegument smooth. Eyes four; eye granules absent or present.
Pharynx bulbous, one subunit. Ceca confluent. Gonads overlapping. Copula-
tory organ composed of MCO and accessory piece. MCO straight or slightly
curved. Accessory piece articulated to MCO by copulatory ligament. Seminal
vesicle fusiform. Prostatic reservoirs round to short, ovate. Germarium ovate
or elongate. Vagina middorsal, looping left caecum. Hooks dactylogyrid, shank
divided in two portions clearly defined; 14, with ancyrocephaline distribution
(4 dorsal, 10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor with
point, shaft, roots well defined. Dorsal anchor with shaft, point, base
composed of two roots. Ventral bar strongly V-shaped; anterior, posterior
projections absent. Dorsal bar rod-shaped; anterior, posterior projections
absent. Parasites of the gills of species of Serrasalmidae (Characiformes).
Type and only species: N. llewellyni KRITSKY, BOEGER & JÉGU, 1997 from
Myleus torquatus, M. rubripinnis (Fig. 3-41).
Notozothecium BOEGER & KRITSKY, 1988
Body fusiform. Tegument smooth. Eyes four; eye granules absent or present.
Pharynx bulbous, one subunit. Ceca confluent. Gonads overlapping. Copula-
tory organ composed of MCO and accessory piece. MCO coiled (usually less
than one ring) or J-shaped. Accessory piece articulated to MCO by copulatory
ligament. Seminal vesicle fusiform. Prostatic reservoirs round to short, ovate.
Germarium ovate or elongate. Vagina dorso-dextral, sclerotized, looping right
caecum. Hooks dactylogyrid, shank divided in two portions clearly defined;
14, with ancyrocephaline distribution (4 dorsal, 10 ventral). Ventral, dorsal
anchor pairs present. Ventral anchor with point, shaft, roots well defined.
Dorsal anchor with shaft, point, base composed of two roots. Ventral bar rod-
shaped; anterior projection present; posterior projection absent. Dorsal bar
rod-shaped or slightly V-shaped; anterior, posterior projections absent. Para-
sites of the gills of species of Serrasalmidae (Characiformes).
82 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
N. bethae KRITSKY, BOEGER & JÉGU, 1996 from Mylesinus paucisquamatus,
Mylesinus paraschomburgkii, Myleus pacu, Myleus rhomboidalis.
N. euzeti KRITSKY, BOEGER & JÉGU, 1996 from Acnodon normani.
N. foliolum KRITSKY, BOEGER & JÉGU, 1996 from Pristobrycon sp.
N. janauachensis BELMONT-JÉGU, DOMINGUES & LATERÇA, 2004 from Colossoma
macropomum.
N. minor BOEGER & KRITSKY, 1988 from Pygocentrus nattereri.
N. penetrarum BOEGER & KRITSKY, 1988 from Pygocentrus nattereri (Type species)
(Figs. 3-42 A-D).
N. robustum KRITSKY, BOEGER & JÉGU, 1996 from Pristobrycon striolatus.
N. teinodendrum KRITSKY, BOEGER & JÉGU, 1996 from Serrasalmus elongatus,
Serrasalmus rhombeus, Serrasalmus gouldingi, Pristobrycon eigenmanni, Serrasalmus
sp., Serrasalmus manuelli, Pristobrycon sp.
Odothecium KRITSKY, BOEGER & JÉGU, 1997
Body fusiform. Tegument smooth. Eyes four; eye granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece. MCO
straight or slightly curved. Accessory piece articulated to MCO by
copulatory ligament. Seminal vesicle C-shaped. Prostatic reservoirs round
to short, ovate. Germarium ovate or elongate. Vagina middorsal, looping
left caecum, sclerotized. Hooks dactylogyrid, shank divided in two
portions clearly defined;14, with ancyrocephaline distribution (4 dorsal,
10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor with point,
shaft, roots well defined. Dorsal anchor with shaft, point, base composed
of two roots. Ventral bar rod-shaped, with slightly projected anterior
margin, with or without medial cleft; posterior projection absent. Dorsal
bar slightly U-shaped; anterior, posterior projections absent. Parasites of
gills of species of Serrasalmidae (Characiformes).
Type and only species: O. raphidiophallum KRITSKY, BOEGER & JÉGU, 1997
from Catoprion mento (Figs. 3-43 A-B)
Pavanelliella KRITSKY & BOEGER, 1998
Body fusiform. Tegument smooth. Eyes four; eyes granules absent or
present. Haptor not differentiated from trunk. Pharynx bulbous, one
subunit. Ceca confluent. Gonads overlapping. Copulatory organ com-
posed of MCO, accessory piece. MCO coiled. Accessory piece one, non-
articulated. Seminal vesicle fusiform. Prostatic reservoirs round to short,
ovate. Germarium ovate or elongate. Vagina sinistro-marginal, sclerotized.
Hooks dactylogyrid, shank divided in two portions clearly defined; 14 on
posterior margin of haptor. Anchors, bars absent. Parasites of the nasal
fossae of species of Pimelodidae (Siluriformes).
P. pavanellii KRITSKY & BOEGER, 1998 from Callophysus macropterus, Pseudoplatys-
toma coruscans (Type species) (Fig. 3-44).
P. scaphiocotylus KRITSKY & MENDOZA-FRANCO, 2003 from Rhamdia guatemalen-
sis.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 83
Philocorydoras SURIANO, 1986
Body fusiform. Tegument smooth. Eyes two; eye granules absent or present.
Pharynx bulbous, one subunit. Ceca confluent. Gonads overlapping. Copu-
latory organ composed of MCO, accessory piece. MCO straight or slightly
curved. Accessory piece articulated to MCO by copulatory ligament.
Seminal vesicle fusiform. Prostatic reservoirs round to short, ovate. Germa-
rium ovate or elongate. Vagina ventral, muscular. Hooks dactylogyrid, shank
simple; 14, with ancyrocephaline distribution (4 dorsal, 10 ventral). Ventral,
dorsal anchor pairs present. Ventral anchor with point, shaft, roots well
defined. Dorsal anchor with shaft, point, base composed of two roots.
Ventral bar slightly U-shaped or rod-shaped; anterior projection absent;
posterior projection present. Dorsal bar slightly U-shaped or rod-shaped;
small subterminal knob at each extremity; posterior projections absent.
Parasites of gills of species of Callichthyidae (Siluriformes).
Type and only species: P. platensis SURIANO, 1986 from Corydoras paleatus
(Figs. 3-45 A-B).
Pithanothecium KRITSKY, BOEGER & JÉGU, 1997
Synonyms: Urocleidus (in part); Cleidodiscus (in part).
Body fusiform. Tegument scaled; annulations on body present. Eyes four;
eye granules absent or present. Pharynx bulbous, one subunit. Ceca
confluent. Gonads overlapping. Copulatory organ composed of MCO,
accessory piece. MCO double. MCO straight or slightly curved. Accessory
piece articulated to MCO by copulatory ligament. Seminal vesicle fusiform.
Prostatic reservoirs round to short, ovate. Germarium ovate or elongate.
Vagina dextro-marginal sclerotized. Hooks dactylogyrid, shank divided in
two portions clearly defined; 14, with ancyrocephaline distribution (4 dorsal,
10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor with point,
shaft, roots well defined. Dorsal anchor with shaft, point, base composed of
two roots. Ventral bar slightly U-shaped; anterior, posterior projections
absent. Dorsal bar slightly U-shaped; anterior, posterior projections absent.
Parasites of the gills of species of Serrasalmidae (Characiformes).
P. amazonensis (MIZELLE & PRICE, 1965) from Pygopristis denticulata, Pygocentrus
nattereri, Catoprion mento, Pristobrycon striolatus.
P. piranhus (KRITSKY, MIZELLE & PRICE, 1965) from Pygopristis denticulata,
Pygocentrus nattereri, Pristobrycon striolatus, Catoprion mento (Type species) (Fig.
3-46).
Protorhinoxenus DOMINGUES & BOEGER, 2002
Body fusiform. Tegument smooth. Eyes four; eye granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece. MCO coiled.
Accessory piece articulated to MCO by copulatory ligament. Seminal
vesicle fusiform. Prostatic reservoirs unknown. Germarium ovate or
elongate. Vagina dextro-marginal, sclerotized. Hooks dactylogyrid, shank
divided in two portions clearly defined; 14, with ancyrocephaline distribu-
84 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
tion (4 dorsal, 10 ventral). Ventral, dorsal anchor pairs present. Ventral
anchor with point, shaft, base very elongated with roots not defined;
accessory sclerite associated with base of ventral anchor. Dorsal anchor
with point, shaft, base very elongate with roots not defined. Ventral bar
rod-shaped; anterior, posterior projections absent. Dorsal bar rod-shaped;
anterior, posterior projections absent. Parasites of the gills of species of
Prochilodus lineatus Prochilodontidae (Characiformes).
Type and only species: P. prochilodi DOMINGUES & BOEGER, 2002 from
Prochilodus lineatus (Fig. 3-47 A-D).
Pseudovancleaveus FRANÇA, ISSAC, PAVANELLI & TAKEMOTO, 2003
Synonyms: Vancleaveus (in part).
Body strongly flattened or fusiform. Tegument smooth. Eyes absent; eye
granules absent or present. Pharynx bulbous, one subunit. Ceca confluent.
Gonads tandem; germarium anterior to testis. Copulatory organ com-
posed of MCO, accessory piece. MCO coiled. Accessory piece articulated
to MCO by copulatory ligament. Seminal vesicle fusiform. Prostatic
reservoirs round to short, ovate. Germarium ovate or elongate. Vagina
sinistro-ventral, muscular. Hooks dactylogyrid, shank simple; 14, with
ancyrocephaline distribution (4 dorsal, 10 ventral). Ventral, dorsal anchor
pairs present. Ventral anchor with point, shaft, roots well defined. Dorsal
anchor with shaft, point, base composed of two roots. Ventral bar slightly
V-shaped; anterior projection absent; posterior projection present. Dorsal
bar slightly U-shaped; anterior, posterior projections absent. Parasites of
gills of Pimelodidae (Siluriformes).
P. paranaensis FRANÇA, ISSAC, PAVANELLI & TAKEMOTO, 2003 from Iheringinchthys
labrosus (Type species) (Fig. 3-48).
P. platensis (SURIANO & INCORVAIA, 1995) from Iheringinchthys labrosus, Pimelodus
clarias maculatus.
Rhinonastes KRITSKY, THATCHER & BOEGER, 1988
Body short, robust, or strongly flattened. Tegument smooth. Eyes four;
eye granules absent or present. Pharynx bulbous, one subunit. Gonads
overlapping. Copulatory organ composed of MCO, accessory piece. MCO
coiled. Accessory piece articulated directly to MCO. Seminal vesicle
fusiform. Prostatic reservoirs round to short, ovate. Germarium ovate or
elongate. Vagina sinistro-marginal, sclerotized. Hooks dactylogyrid, shank
divided in two portions clearly defined; 14, 12 ventral distributed along
margin of haptor, 2 central between anchors. Ventral anchor pair present;
dorsal anchors absent. Ventral anchor with point, shaft, base comprising a
distinct subunit, robust, long, lacking definition of roots. Ventral bar rod-
shaped; two submedian elongate processes on anterior margin; posterior
median projection present. Parasites of nose of species of Prochilodon-
tidae (Characiformes).
Type and only species: R. pseudocapsaloideum KRITSKY, THATCHER & BOEGER,
1988 from Prochilodus nigricans (Figs. 3-49 A-E).
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 85
Rhinoxenus KRITSKY, BOEGER & THATCHER, 1988
Body short, robust, or fusiform. Tegument smooth. Eyes four; eye granules
absent or present. Pharynx bulbous, one subunit. Ceca confluent. Gonads
overlapping. Copulatory organ composed of MCO, accessory piece. MCO
coiled. Accessory piece articulated directly to MCO. Seminal vesicle fusi-
form. Prostatic reservoirs round to short, ovate. Germarium ovate or
elongate. Vaginasinistro-marginal, sclerotized. Hooks dactylogyrid, shank
divided in two portions clearly defined; 14, with ancyrocephaline distribu-
tion (4 dorsal, 10 ventral). Ventral, dorsal anchor pairs present. Ventral
anchor with point, shaft, roots well defined or not defined. Dorsal anchor
spike like. Ventral bar rod-shaped; anterior, posterior projections absent.
Dorsal bar absent. Parasites of nasal fossae of species of Characiformes.
R. anaclaudiae DOMINGUES & BOEGER, 2005 from Triportheus cf. nematurus,
Brycon sp., Triportheus sp. (Characidae, Characiformes).
R. arietinus KRITSKY, BOEGER & THATCHER, 1988 from Rhytiodus argenteofuscus,
Schizodon fasciatum (Anostomidae).
R. bulbovaginatus BOEGER, DOMINGUES & PAVANELLI, 1995 from Salminus
maxillosus (Characidae).
R. curimbatae DOMINGUES & BOEGER, 2005 from Prochilodus cf. lineatus (Prochil-
odontidae, Characiformes).
R. euryxenus DOMINGUES & BOEGER, 2005 from Serrasalmus marginatus, S.
gouldingi, S. rhombeus, S. pilopleura, S. striolatus (Serrasalmidae, Characi-
formes), Leporinus agassizii (Anostomatidae, Characiforems).
R. guianensis DOMINGUES & BOEGER, 2005, from Curimata cyprinoides (Curima-
tidae, Characiformes).
R. nyttus KRITSKY, BOEGER & THATCHER, 1988 from Schizodon fasciatum (Anos-
tomidae).
R. piranhas KRITSKY, BOEGER & THATCHER, 1988 from Pygocentrus nattereri
(Serrasalmidae) (Type species) (Figs. 3-50 A-C).
Sciadicleithrum KRITSKY, THATCHER & BOEGER, 1989
Body short, robust, or cylindrical, or fusiform. Tegument smooth. Eyes
four or two; eye granules absent or present. Pharynx bulbous, one subunit.
Ceca confluent. Gonads overlapping. Copulatory organ composed of
MCO, accessory piece. MCO sinuous, or coiled. Accessory piece one, non-
articulated. Seminal vesicle fusiform. Prostatic reservoirs round to short,
ovate. Germarium ovate or elongate. Vagina ventral, or dextro-marginal,
or sinistro-marginal; sclerotized or muscular. Hooks dactylogyrid, shank
simple; 14, with ancyrocephaline distribution (4 dorsal, 10 ventral).
Ventral, dorsal anchor pairs present. Ventral anchor with point, shaft, roots
well defined. Dorsal anchor with shaft, point, base composed of two roots.
Ventral bar slightly V-shaped, or slightly U-shaped, or rod-shaped; with
double umbelliform membranes on anterior margin; posterior projection
absent. Dorsal bar rod-shaped; anterior, posterior projections absent.
Parasites of gills of species of Cichlidae (Perciformes).
86 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
S. aequidens (PRICE & SCHLUETER, 1989) from Aequidens maroni.
S. bicuense VIDAL-MARTÍNEZ, SCHOLZ & AGUIRRE-MACEDO, 2001 from Archocen-
trus nigrofasciatus.
S. bravohollisae KRITSKY, THATCHER & BOEGER, 1989 from Cichlasoma synspilum,
Petenia splendida, Cichlasoma pearsei.
S. cavanaughi (PRICE, 1966) from Aequidens maroni.
S. ergensi KRITSKY, THATCHER & BOEGER, 1989 from Cichla ocellaris.
S. geophagi KRITSKY, THATCHER & BOEGER, 1989 from Geophagus surinamensis.
S. iphthimum KRITSKY, THATCHER & BOEGER, 1989 from Pterophyllum scalare
(Figs. 3-51 A-F).
S. maculicaudae VIDAL-MARTÍNEZ, SCHOLZ & AGUIRRE-MACEDO, 2001 from
Cichlasoma maculicauda.
S. mexicanum KRITSKY, VIDAL-MARTÍNEZ & RODRIGUES-CANUL, 1994 from
Cichlasoma urophthalmus.
S. nicaraguense VIDAL-MARTÍNEZ, SCHOLZ & AGUIRRE-MACEDO, 2001 from
Amphilophus alfari.
S. splendidae KRITSKY, VIDAL-MARTÍNEZ & RODRIGUES-CANUL, 1994 from
Petenia splendida.
S. tortrix KRITSKY, THATCHER & BOEGER, 1989 from Uaru amphiacanthoides.
S. umbilicum KRITSKY, THATCHER & BOEGER, 1989 from Cichla ocellaris.
S. uncinatum KRITSKY, THATCHER & BOEGER, 1989 from Cichla ocelaris (Type
species).
S. variabilum (MIZELLE & KRITSKY, 1969) from Symphysodon discus.
S. meekii MENDOZA-FRANCO, SCHOLZ & VIDAL-MARTÍNEZ, 1997 from Archocen-
trus nigrofasciatus.
Telethecium KRITSKY, VAN EVERY & BOEGER, 1996
Body fusiform. Tegument smooth. Eyes four; eye granules absent. Haptor not
differentiated from trunk. Pharynx bulbous, one subunit. Ceca confluent.
Gonads overlapping. Copulatory organ composed of MCO, accessory piece.
MCO coiled. Accessory piece articulated directly to MCO, or articulated to
MCO by copulatory ligament. Seminal vesicle fusiform. Prostatic reservoirs
round to short, ovate. Germarium ovate or elongate. Vagina sinistro-marginal,
sclerotized. Hooks dactylogyrid, shank divided in two portions clearly defined;
14 on posterior margin of haptor. Ventral, dorsal anchor pairs absent. Ventral,
dorsal bars absent. Parasites of nose of species of Osteoglossidae (Osteoglo-
ssiformes) and Pristigasteridae (Clupeiformes).
T. nasalis KRITSKY, VAN EVERY & BOEGER, 1996 from Osteoglossum bicirrhosum
(Osteoglossidae) (Type species) (Figs. 3-52 A-B).
T. paniculum KRITSKY, VAN EVERY & BOEGER, 1996 from Pellona flavipinnis
(Pristigasteridae).
Tereancistrium KRITSKY, THATCHER & KAYTON, 1980
Body fusiform. Tegument smooth. Eyes four, or two; eye granules absent
or present. Pharynx bulbous, one subunit. Ceca confluent. Gonads
overlapping. Copulatory organ composed of MCO, accessory piece. MCO
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 87
coiled. Accessory piece one, non-articulated. Seminal vesicle fusiform.
Prostatic reservoirs round to short, ovate. Germarium ovate or elongate.
Vagina sinistro-marginal, sclerotized or muscular. Hooks dactylogyrid,
shank simple; 14, with ancyrocephaline distribution (4 dorsal, 10 ventral).
Ventral, dorsal anchor pairs present. Ventral anchor with point, shaft, roots
well defined; accessory sclerite associated with base present. Dorsal
anchor with shaft, point, base composed of two roots. Ventral bar rod-
shaped; anterior margin smooth or with slightly projected margin, with or
without medial cleft. Dorsal bar slightly V-shaped, or strongly V-shaped;
anterior projection absent; posterior projection present or absent. Parasites
of gills of species of Characiformes.
T. kerri KRITSKY, THATCHER & KAYTON, 1980 from Brycon melanopterus (Charac-
idae) (Type species) (Figs. 3-53 A-B).
T. ornatus KRITSKY, THATCHER & KAYTON, 1980 from Prochilodus reticulatus
(Curimatidae).
T. parvus KRITSKY, THATCHER & KAYTON, 1980 from Leporinus fasciatus (Anos-
tomidae).
Trinibaculum KRITSKY, THATCHER & KAYTON, 1980
Body short, robust. Tegument smooth. Eyes four; eye granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads tandem;
germarium anterior to testis. Copulatory organ composed of MCO, accesso-
ry piece. MCO straight or slightly curved. Accessory piece articulated
directly to MCO. Seminal vesicle fusiform. Prostatic reservoirs round to
short, ovate. Germarium ovate or elongate. Vagina dextro-ventral, sclero-
tized. Hooks dactylogyrid, shank simple; 14, with ancyrocephaline distribu-
tion (4 dorsal, 10 ventral). Ventral, dorsal anchor pairs present. Ventral
anchor with point, shaft, roots well defined. Dorsal anchor with shaft, point,
base composed of two roots. Ventral bar slightly V-shaped; anterior,
posterior projections absent. Dorsal bar double, rod-shaped; anterior,
posterior projections absent. Parasites of gills of species of Characiformes.
Type and only species: T. brazilensis KRITSKY, THATCHER & KAYTON, 1980
from Brycon melanopterus (Fig. 3-54).
Trinidactylus HANEK, MOLNAR & FERNANDO, 1974
Body fusiform. Tegument smooth. Annulations on body absent. Eyes
four, eye granules absent or present. Pharynx bulbous, one subunit.
Gonads tandem; germarium anterior to testis. Testis single. Copulatory
organ composed of MCO, accessory piece. MCO coiled, loose coils, with
non-inflated proximal portion. Accessory piece one, non-articulated.
Seminal vesicle unknown. Prostatic reservoirs unknown. Germarium ovate
or elongate, solid. Vagina single, ventral. Vaginal bar, accessory vaginal
sclerite absent. Hooks dactylogyrid. Hook shank simple. Hooks 14, with
ancyrocephaline distribution (4 dorsal,10 ventral). Hooks not on pedun-
cles. Hook pair 2 on the haptor, close to hooks pairs 3, 4; hook pair 5
similar to other pairs. Ventral, dorsal anchor present. Ventral anchor rod-
88 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
shaped; ventral anchor filament delicate, often inconspicuous. Accessory
sclerite associated with base of ventral anchor absent. Dorsal anchor
dactylogyrid, with shaft, point and base composed of two roots. Fold on
inner superficial root of dorsal anchor absent. Ventral bar rod-shaped.,
with smooth surface on anterior margins. Groove along length of ventral
bar absent. Ventral bar without posterior median projection. Dorsal bar
absent. Parasite of species of Cichlidae (Perciformes).
Type and only species: T. cichlasomatis HANEK, MOLNAR & FERNANDO, 1974
from Cichlasoma bimaculatum (Fig. 3-55).
Trinigyrus HANEK, MOLNAR & FERNANDO, 1974
Body fusiform. Tegument smooth. Eyes absent; eye granules absent.
Pharynx bulbous, one subunit. Ceca confluent. Gonads overlapping.
Copulatory organ composed of MCO, accessory piece. MCO sinuous, or
straight, or slightly curved. Accessory piece one, non-articulated. Seminal
vesicle fusiform. Prostatic reservoirs round to short, ovate. Germarium
ovate or elongate. Vagina dextro-marginal, sclerotized or muscular. Hooks
dactylogyrid, shank divided in two portions clearly defined; 14, with
ancyrocephaline distribution (4 dorsal, 10 ventral). Ventral anchor with
point, shaft, roots not defined. Dorsal anchor absent. Ventral bar with
tapering extremities, rod-shaped, anterior absent; posterior projections
present; groove along entire length of bar present. Dorsal bar absent.
Parasites of gills of species of Loricariidae (Siluriformes).
T. acuminatus KRITSKY, BOEGER & THATCHER, 1986 from Acanthicus hystrix
(Figs. 3-56 A-E).
T. hypostomatis HANEK, MOLNAR & FERNANDO, 1974 from Hypostomus robinii
(Type species).
T. mourei BOEGER & JÉGU, 1994 from Hypostomus marginatus.
T. tentaculoides KRITSKY, BOEGER & THATCHER, 1986 from Hypoptopoma thora-
cathum.
Unibarra SURIANO & INCORVAIA, 1995
Body fusiform. Tegument smooth. Eyes absent; eye granules absent.
Pharynx bulbous, one subunit. Ceca confluent. Gonads tandem; germari-
um anterior to testis. Copulatory organ composed of MCO, accessory
piece. MCO straight or slightly curved. Seminal vesicle fusiform. Prostatic
reservoirs round to short, ovate. Germarium ovate or elongate. Vagina
ventral, sclerotized. Hooks dactylogyrid, entire shank inflated, conferring a
robust morphology to hook; 14, with ancyrocephaline distribution (4
dorsal, 10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor
point, shaft, roots not defined. Dorsal anchor with shaft, point, base not
clearly separated in roots. Ventral bar rod-shaped; anterior projection
absent; posterior projection present. Dorsal bar absent. Parasites of gills
of species of Pimelodidae (Siluriformes).
Type and only species: U. paranoplatensis SURIANO & INCORVAIA, 1995 from
Pimelodus clarias maculatus, Paulicea luetkeni (Fig. 3-57)
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 89
Unilatus MIZELLE & KRITSKY, 1967
Synonym: Diaccessorius
Body fusiform. Tegument smooth. Eyes absent; eye granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads tandem;
germarium anterior to testis. Copulatory organ composed of MCO, accessory
piece. MCO coiled, with tight coils, cork-screw like. Accessory piece one, non-
articulated. Seminal vesicle fusiform. Prostatic reservoirs round to short,
ovate. Germarium ovate or elongate. Vagina ventral or sinistro-marginal,
sclerotized or muscular. Hooks dactylogyrid, shank divided in two portions
clearly defined or shank simple; 14, 8 dorsal, 6 ventral. Two pairs of dorsal
anchors, anterior, posterior. Posterior pair of anchors with point, shaft, roots
not defined. Anterior pair of anchors with shaft, point, base composed of two
roots. Posterior bar slightly V-shaped or rod-shaped; anterior projection
absent; posterior projection absent or present. Anterior bar slightly U-shaped
or strongly V-shaped; anterior projection absent; posterior projections present
or absent. Parasites of gills of species of Loricariidae (Siluriformes).
U. anoculus (PRICE, 1968) from Hypostomus bolivianus.
U. brevispinus SURIANO, 1985 from Pterigoplichthys multiradiatus.
U. brittani MIZELLE, KRITSKY & CRANE, 1968 from Hypostomus sp., Plecostomus sp.
U. dissimilis SURIANO, 1985 from Hemiancistris sp.
U. longispinus SURIANO, 1985 from Pterigopliichthys multiradiatus.
U. scaphirhynchae SURIANO, 1985 from Hemiancistrus scaphirhynchae.
U. unilatus MIZELLE & KRITSKY, 1967 from Hypostomus robinii, Plecostomus sp.
(Type species) (Figs. 3-58 A-E).
Urocleidoides sensu stricto MIZELLE & PRICE, 1964
Body fusiform. Tegument smooth. Eyes four, or two, or absent; eye granules
absent or present. Pharynx bulbous, one subunit. Ceca confluent. Gonads
overlapping. Copulatory organ composed of MCO, accessory piece. MCO
coiled. Accessory piece one, non-articulated, or articulated directly to MCO,
or articulated to MCO by copulatory ligament. Seminal vesicle fusiform.
Prostatic reservoirs round to short, ovate. Germarium ovate or elongate.
Vagina dextral or sinistro-marginal; sclerotized or muscular; vaginal accesso-
ry sclerite present. Hooks dactylogyrid, shank divided in two portions clearly
defined, or shank simple; 14, with ancyrocephaline distribution (4 dorsal, 10
ventral). Ventral, dorsal anchor pairs present. Ventral anchor with point,
shaft, roots well defined. Dorsal anchor with shaft, point, base composed of
two roots. Ventral bar slightly V-shaped, or slightly U-shaped, or rod-shaped;
anterior, posterior projections absent. Dorsal bar slightly V-shaped, or
slightly U-shaped; anterior, posterior projections absent. Parasites of species
of Cyprinodontiformes and Characiformes.
U. anops KRITSKY & THATCHER, 1974 from Characidium caucanum (Characidae,
Characiformes).
U. curimatae MOLNAR, HANEK & FERNANDO, 1974 from Curimata argentea
(Curimatidae, Characiformes).
90 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
U. eremitus KRITSKY, THATCHER & BOEGER, 1986 from Hoplias malabaricus
(Erythrinidae, Characiformes).
U. paradoxus KRITSKY, THATCHER & BOEGER, 1986 from Rhytiodus microlepis
(Anostomidae, Characiformes) (Figs. 3-59 A-D).
U. reticulatus MIZELLE & PRICE, 1964 from Lebistes reticulata (Poeciliidae,
Cyprinodontiformes) (Type species).
U. vaginoclaustrum JOGUNOORI, KRITSKY & VENKATANARASAIAH, 2004 from
Xiphophorus helleri (Poeciliidae, Cyprinodontiformes).
Vancleaveus KRITSKY, THATCHER & BOEGER, 1986
Body fusiform. Tegument smooth. Eyes absent; eye granules absent or
present. Pharynx bulbous, one subunit. Ceca confluent. Gonads overlap-
ping. Copulatory organ composed of MCO, accessory piece. MCO J-
shaped. Accessory piece one, non-articulated. Seminal vesicle fusiform,
with thick walls, very long, extending from level of base of MCO to initial
portion of germarium. Prostatic reservoirs very long, often looping
posteriorly. Germarium ovate or elongate. Vagina ventral or dextro-
ventral, sclerotized. Hooks dactylogyrid, entire shank inflated, conferring a
robust morphology to hook; 14, with ancyrocephaline distribution (4
dorsal, 10 ventral). Ventral, dorsal anchor pairs present. Ventral anchor
with point, shaft, roots well defined. Dorsal anchor with shaft, point, base
composed of two roots; fold on inner superficial root of dorsal anchor
present. Ventral bar slightly V-shaped or rod-shaped; anterior projection
present; dorsal projection absent. Dorsal bar rod-shaped; anterior projec-
tion absent or present; posterior projection absent. Parasites of gills of
species of Siluriformes, most commonly on Pimelodidae.
V. cicinnus KRITSKY, THATCHER & BOEGER, 1986 from Pimelodus spp., Phracto-
cephalus hemiliopterus (Pimelodidae).V. fungulus KRITSKY, THATCHER & BOEGER, 1986 from Pseudoplatystoma sp.,
Pseudoplatystoma fasciatum (Pimelodidae).
V. janauacaensis KRITSKY, THATCHER & BOEGER, 1986 from Pterodoras granulosus
(Doradidae) (Type species) (Figs. 3-60 A-B).
V. platyrhynchi KRITSKY, THATCHER & BOEGER, 1986 from Hemisorubim platyrhyn-
chos (Pimelodidae).
Genera of Dactylogyridae, Ancyrocephalinae not well known or of questionable status.
The diagnosis and/or species composition of the genera listed below is
complicated by inadequate species descriptions, lack of evident diagnostic
features, or represent catchall taxa that require extensive revision.
Amphocleithrium PRICE & ROMERO, 1969
A. paraguayensis PRICE & ROMERO, 1969 from Pseudoplatystoma sp., Pseudoplatysto-
ma coruscans (Pimelodidae, Siluriformes).
Cleidodiscus MUELLER, 1934
C. microcirrus PRICE & SCHLUETER, 1967 from Hemiodus semitaeniatus (Hemi-
odontidae, Characiformes).
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 91
Palombitrema PRICE, C.E. & W.A. BUSSING, 1968
Syn: Androspira SURIANO, 1981
P. heteroancistrium (PRICE & BUSSING, 1968) from Astyanax bimaculatus (Charac-
idae, Characiformes).
P. chascomusense (SURIANO, 1981) from Curimata gilberti (Curimatidae, Characi-
formes).
P. triangulum (SURIANO, 1981) from Curitimata gilberti (Curimatidae, Characi-
formes).
Salsuginus BEVERLEY-BURTON, 1984
Salsuginus neotropicalis MENDOZA-FRANCO & VIDAL-MARTINEZ, 2001 from
Belonesox belizanus (Atheriniformes, Poeciliidae).
Urocleidoides sensu lato
U. amazonensis MIZELLE & KRITSKY, 1969 from Phractocephalus hemiliopterus
(Pimelodidae, Siluriformes).
U. astyanacis GIOIA, CORDEIRO & ARTIGAS, 1988 from Astyanax scabripinnis,
Astyanax fasciatus (Characidae, Characiformes).
U. carapus MIZELLE, KRITSKY & CRANE, 1968 from Gymnotus carapo (Gym-
notidae, Gymnotiformes).
U. catus MIZELLE & KRITSKY, 1969 from Phractocephalus hemiliopterus (Pimelo-
didae, Siluriformes).
U. corydori MOLNAR, HANEK & FERNANDO, 1974 from Corydoras aeneus (Callich-
thyidae, Siluriformes).
U. costaricensis (PRICE & BUSSING, 1967) from Curimata argentea (Curimatidae,
Characiformes), Astyanax bimaculatus (Characidae, Characiformes) Asty-
anax fasciatus (Characidae, Characiformes).
U. gymnotus MIZELLE, KRITSKY & CRANE, 1968 from Gymnotus carapo (Gym-
notidae, Gymnotiformes).
U. lebedevi KRITSKY & THATCHER, 1976 from Pimelodus grosskopfi (Pimelodidae,
Siluriformes).
U. margolisi MOLNAR, HANEK & FERNANDO, 1974 from Corydoras aeneus (Calli-
chthyidae, Siluriformes).
U. megorchis MIZELLE & KRITSKY, 1969 from Sorubim lima (Pimelodidae,
Siluriformes).
U. strombicirrus (PRICE & BUSSING, 1968) from Astyanax fasciatus (Characidae,
Characiformes).
U. trinidadensis MOLNAR, HANEK & FERNANDO, 1974 from Astyanax bimaculatus
(Characidae, Characiformes).
U. virescens MIZELLE, KRITSKY & CRANE, 1968 from Eigenmannia virescens
(Sternopygidae, Gymnotiformes).
92 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
VIII. Plates of Monogenoidea (Figs. 3-1 to 3-64)
Abreviation used:
ap – accessory piece
ascl – accessory sclerite
bo – buccal organ
ca – caecum
cg – cephalic gland
cl – copulatory ligament
db – deep bar
dr – deep root
e – embryo
eg – egg
fh – FH loop
ge – germarium
he – heel
ho – head organ
hs – haptoral sucker
mco – male copulatory organ
mg – Mehlis gland
ph – pharynx
pr – prostatic reservoir
pt – point
sb – superficial bar
sf – shaft
sk – shank
sl – spinelet
sp – spine
sr – seminal receptacle
sr – superficial root
sv – seminal vesicle
te – testis
to – toe
va – vagina
vi – vitellaria
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 93
3-1. Paraheteronchocotyle amazonensis: A. entire; B. large sucker sclerite; C. small sucker sclerite; 3-2.
Paranaella luquei: A. entire; B. clamp; 3-3. Potamotrygonocotyle tsalickisi: A. entire; B. anchor; 3-4. Accessorius
peruensis: A. entire; B. accessory sclerite; C. male copulatory organ; D. marginal hook; E. ventral bar-
shield complex; F. anchor; hooks are numbered according to the system proposed by MIZELLE (1936).
All scales in micrometers (µm), except 3-2A.
3-1A
3-1B
3-2B
3-1C
3-2A
3-4B
3-3B
3-4C
3-4D
3-4F
3-4E 3-4A3-3A
dr
sf
sr
pt
ph
mco
sv
e
ge
ca
3
4
5
6
7
2
1
8
50
50
50
30
50
50
te
500
150
50
bo
hs
250
1 m
m
94 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
3-5. Anacanthocotyle anacanthocotyle: A. entire; B. marginal hook; C. male copulatory organ; 3-6.
Gyrodactylus geophagensis: A. entire; B. marginal hook; C. male copulatory organ; D. anchor; E. anchor-
superficial bar complex; 3-7. Hyperopletes malmbergi: A. entire; B. male copulatory organ; C. marginal
hook; D. anchor-superficial bar complex; 3-8. Nothogyrodactylus plaesiophallus: A. entire; B. accessory
copulatory sclerites; C. anchor; D. marginal hook; E. anchor-superficial bar complex. All scales in
micrometers (µm).
3-6B
eg
mg
ge
ho
cg
db
af
sb
to
sk
he
sp
sl
fh
sfpt
sv
3-5B 3-5C
3-6C
3-6D
3-5A 3-6E 3-6A
3-8B
3-7B
3-8C 3-8D
3-7C
3-7D
3-8E 3-8A
3-7A
420
20
2020
15 100
40
3
50
25
25
25
200
25
200
25
50
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 95
3-9. Oogyrodactylus farlowellae: A. entire; B. male copulatory organ; C. marginal hook; D. anchor; 3-10.
Phanerothecium caballeroi: A. entire; B. male copulatory organ; C. marginal hook; D. anchor; E. anchor-
superficial bar complex; 3-11. Scleroductus sp.: A. entire (no publish data); B. superficial bar-shield
complex; C-D. male copulatory organ seen from different angle; E. marginal hook; F. anchor; 3-12.
Diplectanum decorum: A. entire (composite); B. vagina; C. copulatory complex; D. ventral anchor; E.
ventral bar; F. dorsal bar. All scales in micrometers (µm).
3-10B
3-10C
3-9A 3-9D
3-10D
3-10E 3-10A
3-11A
3-9C
3-11B 3-11C
3-11D
3-11E
3-11F
3-9B
3-12A
3-12B
3-12C 3-12D
3-12E
3-12F
40
sq
100
40
40
25
20
50
20
20
200
20
70
5025
25
70
100
50
96 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
3-13. Ameloblastella chavarrai: A. entire; B. vagina; C. male copulatory organ; D. ventral bar; E. dorsal
bar; 3-14. Amphithecium calycinum: A. entire; B. ventral anchor. C. dorsal anchor; D. male copulatory
organ; E. ventral bar; F. dorsal bar; hooks are numbered according to the system proposed by MIZELLE
(1936); 3-15. Anacanthoroides mizellei: A. entire; B. male copulatory organ; C. hooks; 3-16. Anacanthorus
sciponophallus: A. entire; B-D. hooks; E. male copulatory organ. All scales in micrometers (µm).
3-13A
3-13B
3-13C
3-13D
3-13E
3-14C
3-14A
3-14B
3-14D
3-14E
3-14F
3-16A
3-16B
3-16C
3-16D
3-16E
3-15A
3-15B
3-15C
vi
te
cl
ap
vg
va
vi
ap
mco
cl
mco
1 2
3
4
5
6
1
2
3 4
5
6
7
100
20
20
25
100
100
30
200
25
7
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 97
3-17. Male copulatory organ of Anacanthorus spp.: A. A. bellus; B. A. calophallus; C. A. carinatus; D. A.
cornutus; E. A. dipelecinus; F. A. glyptophallus; G. A. furculus; H. A. euryphallus; I. A. hoplophallus; J. A.
mastigophallus; K. A. pithophallus; L.A. periphallus; M. A. lygophallus; N. A. pelorophallus; O. A. xaniophallus;
P. A. spinatus. All scales = 25 micrometers (µm).
3-17A
3-17B
3-17C 3-17D
3-17E
3-17F
3-17G
3-17I
3-17J
3-17H
3-17L3-17K
3-17M 3-17N 3-17O 3-17P
mco
ap
98 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
3-18. Ancistrohaptor falciferum: A. entire; B. ventral bar; C. male copulatory organ; 3-19. Annulotrematoidesamazonicus: A. entire; B. male copulatory organ; 3-20. Aphanoblastela travassoi: A. entire; B. male
copulatory organ; C. ventral bar; D. dorsal bar; 3-21. Cacatuocotyle paranaensis: A. entire; B. male
copulatory organ. All scales in micrometers (µm).
3-18A
3-18B
3-18C
3-19A
3-19B
3-20A
3-20B
3-20C
3-20D
3-21A
3-21B
sr
25
100
100
25
25
100
100
25
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 99
3-22. Calpidothecioides pygopristi: A. entire; B. ventral bar; 3-23. Calpidothecium crescentis: A. entire; B.
ventral anchor; C. dorsal anchor; 3-24. Cosmetocleithrum gussevi: A. entire; B. ventral bar; C. dorsal bar;
D. male copulatory organ; E. ventral anchor; F. dorsal anchor; 3-25. Curvianchoratus singularis: A.
entire; B-C. dorsal anchor; D. ventral anchor. All scales in micrometers (µm).
3-22A
3-22B
3-23A
3-23B
3-24A
3-24B
3-24C
3-24D
3-24E 3-24F
3-25A
3-25B
3-25C
3-25D
sv
100
25
100
pr
25
30
100
200
30
50
3-23C
100 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
3-26. Dawestrema cycloancistrium: A. entire; B. vagina; C. ventral bar; 3-27. Demidospermus cornicinus: A.
entire; B. vagina; C. ventral bar; D. dorsal bar; E-F. hooks; 3-28. Diaphorocleidus armillatus: A. entire; B.
male copulatory organ; C. ventral bar; 3-29. Enallothecium aegidatum; 3-30. Euryhaliotrema chaoi: A.
entire; B. male copulatory organ. All scales in micrometers (µm).
3-26A
3-26B
3-26C
3-27A
3-27B
3-27C
3-27D
3-27E 3-27F
3-28A
3-28B
3-28C
3-30A3-293-30B
25
25
200
25500
30
50
20
200
50
50
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 101
3-31. Gonocleithrum planacrus: A. entire; B. gonadal bar; C. ventral bar; D. male copulatory organ; 3-32.
Gussevia asota: A. entire; B. dorsal bar; C. ventral anchor; D. male copulatory organ; 3-33. Heterothecium
globatum; 3-34. Heterotylus heterotylus: A. entire; B. ventral bar; C. male copulatory organ; D. ventral
anchor. All scales in micrometers (µm).
3-31A
3-31B
3-31C
3-31D 3-32A
3-32B
3-32C
3-32D
3-33 3-34A
3-34B
3-34C
3-34D
100
20
50
30
10030
100
vag
vgb
102 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
3-35. Jainus sp.: A. entire; B. male copulatory organ; C. hook; D. ventral anchor; 3-36. Kritskyia moraveci:
A. entire; B. hook (ventral view); C. hook; 3-37. Liguadactyloides brinkmanni: A. entire; B. ventral anchor;
C. dorsal anchor; D. hook. All scales in micrometers (µm).
3-35A
3-35B
3-35C
3-35D 3-36A
3-36B
3-36C
3-37A
3-37B 3-37C
3-37D
pr
500
10
1010
10
10
50
200
25
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 103
3-38. Monocleithrium lavergneae; 3-39. Mymarothecium dactylotum: A. entire; B. ventral bar; C. male copu-
latory organ; 3-40. Notothecium mizellei: A. entire; B. dorsal bar; 3-41. Notothecioides llewellyni; 3-42.
Notozothecium penetrarum: A. entire; B. male copulatory organ; C. ventral bar; D. dorsal bar. All scales
in micrometers (µm).
3-39A
3-39B
3-39C
100
3-38 3-40A3-40B
3-41
3-42A
3-42B
3-42C
3-42D
20
50
3040
20
30
300
30
100
104 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
3-43. Odothecium raphidiophallum: A. entire; B. ventral bar; 3-44. Pavanelliella pavanelli; 3-45. Philocorydoras
platensis: A. entire; B. ventral bar; 3-46. Pithanothecium piranhus; 3-47. Protorhinoxenus prochilodi: A. entire;
B. dorsal anchor; C. ventral anchor; D. hook. All scales in micrometers (µm).
3-43A
3-43B
3-44
3-47A
3-47B
3-45A
3-45B
3-47C
3-47D3-46
100
200
100
100
50
50
100
25
25
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 105
3-48. Pseudovancleaveus paranaensis; 3-49. Rhinonastes pseudocapsaloideum: A. entire; B. ventral bar; C. anchor;
D. hook; E. male copulatory organ; 3-50. Rhinoxenus piranhas: A. entire; B. dorsal haptorial spike; C.
ventral anchor; 3-51. Sciadicleithrum iphthimum: A. entire; B-F. ventral bar; B. S. ergensi; C. S. uncinatum;
D. S. geophagi; E. S. umbilicum; F. S. tortrix. All scales in micrometers (µm).
3-49A
3-49B 3-49C
3-49D
3-49E
3-48
3-51A
3-50C
3-50A
3-50B
3-51B
3-51C
3-51D
3-51E
3-51F
100
200
30
15
20
30
50
125
100
30
30
30
106 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
3-52. Telethecium nasalis: A. entire; B. lateral view of specimen showing relationship of body and
copulatory bag (scale not provide); 3-53. Tereancistrium kerri: A. entire; B. ventral anchor and accessory
anchor sclerite; 3-54. Trinibaculum brazilensis; 3-55. Trinidactylus cichlasomatis (haptor); 3-56. Trinigyrus
acuminatus: A. entire; B. anchor; C. bar; D male copulatory organ; E. vagina and distal portion of
seminal receptacle. All scales in micrometers (µm).
3-52A
3-52B
3-53A3-53B
3-56A
3-54
3-55 3-56B
3-56C
3-56D
3-56E
ascl
100
20
100
100
40
30
100
30
30
30
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 107
3-57. Unibarra paranoplatensis; 3-58. Unilatus unilatus: A. anterior bar; B. anterior anchor; C. posterior
bar; D. posterior anchor; E. accessory piece; 3-59. Urocleioides paradoxus: A. entire; B. hook (pairs 1, 5);
C. hook (pairs 2, 3, 4, 6, 7); D. vaginal sclerite; 3-60. Vancleaveus janauacaensis: A. entire; B. dorsal bar.
All scales in micrometers (µm).
3-58A 3-58B
3-58C
3-58D
3-57
3-59A
3-59B
3-59C
3-59D
3-58E
3-60A
3-60B
100
30
30
100
30
400
108 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
3-61. Histological section of gill filament showing haptor of Linguadactyloides with an anchor secured
in the cartilage; 3-62. Linguadactyloides penetrated into gill filament showing epithelial hyperplasia
around point of entry. (Original photographs).
3-62
3-61
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 109
3-63. Linguadactyloides penetrated within gill filament showing missing ephitelium; 3-64. Undescribed
monogenoid penetrated into the gill filament of Oxydoras niger showing tumeroid caused by the
haptor. (Original photographs).
3-63
3-64
CyanMagentaYellowBlack page 109
250 µm
110 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
IX. Cited and general references
AGARWAL, N. & D.C. KRITSKY (1998): Neotropical Monogenoidea. 33. Three new species of
Ancistrohaptor n. g. (Dactylogyridae, Ancyrocephalinae) on Triportheus spp. (Teleostei, Charac-
idae) from Brazil, with checklists of ancyrocephalines recorded from Neotropical characi-
form fishes. - Systematic Parasitology 39(1): 59-69.
AN, L., JARA, C.A. & D.K. CONE (1991): Five species of Gyrodactylus NORDMANN, 1832 (Monogenea)
from freshwater fishes of Peru. - Can. J. Zool. 69: 1199-1201.
BELMONT-JÉGU, E., DOMINGUES, M.V. & M.L. MARTINS (2004): Notozothecium janauachensis n. sp.
(Monogenoidea: Dactylogyridae) from wild and cultured tambaqui, Colossoma macropomum
(Teleostei: Characidae: Serrasalminae) in Brazil. - Zootaxa 736: 1-8.
BOEGER, W.A. & E. BELMONT-JÉGU (1994): Neotropical Monogenoidea. 21. Trinigyrus mourei sp. n.
(Dactylogyridae) from the gills of the Amazonian catfish Hypostomus marginatus (Loricariidae).
- Amazoniana 13(1/2): 13-16.
BOEGER, W.A. & D.C. KRITSKY (1988): Neotropical Monogenea. 12. Dactylogyridae from Serrasal-
mus nattereri (Cypriniformes: Serrasalmidae) and aspects of their morphologic variation and
distribution in the Brazilian Amazon. - Proc. Helminthol. Soc. Wash. 55(2): 188-213.
BOEGER, W.A. & F. POPAZOGLO (1995): Neotropical Monogenoidea. 23. Two new species of
Gyrodactylus from cichlid and characid fishes of Brazil. - Mem. Inst.Oswaldo Cruz 90: 689-694.
BOEGER, W.A., DOMINGUES, M.V. & D.C. KRITSKY (1996): Neotropical Monogenoidea. 32.
Cacatuocotyle paranaensis n. g., n. sp. (Dactylogyridae, Ancyrocephalinae) from Characidium spp.
(Teleostei, Characidae) from the State of Paraná, Brazil. - Systematic Parasitology 37: 1-4.
BOEGER, W.A., DOMINGUES, M.V. & G.C. PAVANELLI (1997): Neotropical Monogenoidea. 24. Rhinoxenus
bulbovaginatus n. sp. (Ancyrocephalinae) from the nasal cavity of Salminus maxillosus (Osteichthyes,
Characidae) from the Rio Paraná, Parana, Brazil. - Mem. Inst. Oswaldo Cruz 90: 695-694.
BOEGER, W.A., HUSAK, W.S. & M.L. MARTINS (1995): Neotropical Monogenoidea. 25. Anacanthorus
penilabiatus n. sp. (Dactylogyridae, Anacanthorinae) from Piaractus mesopotamicus (Osteichthyes,
Serrasalmidae), cultivated in the State of São Paulo, Brazil. - Mem. Inst. Oswaldo Cruz 90: 699-701.
BOEGER, W.A., KRITSKY, D.C. & E. BELMONT-JÉGU (1994): Neotropical Monogenoidea. 20. Two new
species of oviparous Gyrodactylidea (Polyonchoinea) from loricariid catfishes (Siluriformes)
in Brazil and the phylogenetic status of Ooegyrodactylidae HARRIS, 1983. - J. Helminthol. Soc.
Wash. 61: 34-44.
BOEGER, W.A., KRITSKY, D.C. & M. PIE (2003): The context of diversification of the viviparous
Gyrodactylidae (Platyhelminthes: Monogenoidea). - Zoologica Scripta 32(5): 437-448.
BOEGER, W.A., PIASECKI, W. & E. SOBECKA (2002): Neotropical Monogenoidea. 44. Mymarothecium
viatorum sp. n. (Ancyrocephalinae) from the gill of Piaractus brachypomus (Serrasalmidae,
Teleostei) captured in a warm-water canal of a power plant in Szczecin, Poland. - Acta
Ichthyologica et Piscatoria 32(2): 158-161.
BOEGER, W.A., TANAKA, L.K. & G.C. PAVANELLI (2001): Neotropical Monogenoidea. 39. A new
species of Kritskyia (Dactylogyridae, Ancyrocephalinae) from the ureters and urinary bladder
of Serrasalmus marginatus and S. spilopleura (Characiformes, Serrasalmidae) from southern
Brazil with an emended generic diagnosis. - Zoosystema 23: 5-10.
BRANDES, G. (1894): Fridericianella ovicola n.g., n.sp. Ein neuer monogenetischer Trematode. - Abh.
Naturf. Ges. Halle 20, Jubiläums-Festschrift: 303-310.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 111
BYCHOWSKY, B.E. (1957): Monogenetic trematodes, their systematics and phylogeny. - Akad. Nauk.
U.S.S.R., Moscow (translated from Russian by AIBS, Washington, D.C.): 509 pp.
CABLE, J.C., VAN OOOSTERHOUT, C., BARSON, N. & P.D. HARRIS (2005): Gyrodactylus pictae n. sp.
(Monogenea: Gyrodactylidae) from the Trinidadian swamp guppy Poecilia picta REGAN, with a
discussion on species of Gyrodactyls VON NORDMANN, 1832 and their poeciliid hosts. -
Systematic Parasitology 60: 159-164.
COHEN, S.C. & A. KOHN (2005): A new species of Mymarothecium and new host and geographical
records for M. viatorum (Monogenea: Dactylogyridae), parasites of freshwater fishes in Brazil.
- Folia Parasitologica 52: 307-310.
CUGLIANNA, A.N., CORDEIRO, N.S. & J.L. LUQUE (2003): Annulotrematoides bryconi sp. n. (Monogenea:
Dactylogyridae) parasitic on Brycon cephalus (Osteichthyes: Characidae) from Brazil. - Folia
Parasitologica 50: 272-274.
DALLWITZ, M. J. (1974): A flexible computer program for generating identification keys. -Systematic.
Zoology 23: 50–7.
DALLWITZ, M. J. (1980): A general system for coding taxonomic descriptions. -Taxon 29: 41–6.
DOMINGUES, M.V. & W.A. BOEGER (2002): Neotropical Monogenoidea. 40. Protorhinoxenus prochilodi
gen. n., sp. n. (Monogenoidea: Ancyrocephalinae), parasite of Prochilodus scrofa (Characi-
formes: Prochilodontidae) from South Brazil. - Folia Parasitologica 49: 35-38.
DOMINGUES, M.V. & W.A. BOEGER (2005): Neotropical Monogenoidea. 47. Phylogeny and coevolu-
tion of species of Rhinoxenus (Plathyhelminthes, Monogenoidea, Dactylogyridae) and their
characiformes hosts (Teloestei, Ostariophysi) with description of four new species. -Zoosyste-
ma 27(3): 441-467.
FERRAZ, E., SHINN, A.P. & C. SOMMERVILLE (1994): Gyrodactylus gemini n. sp. (Monogenea: Gyrodac-
tylidae), a parasite of Semaprochilodus taeniurus (Steindachner) from the Venezuelan Amazon. -
Systematic Parasitology 29: 217-222.
FRANCA, J.G., ISSAC, A., PAVANELLI, G.C. & R.M. TAKEMOTO (2003): Dactylogyridae (Monogenea) from
the gills of Iheringichthys labrosus (Osteichthyes: Pimelodidae) from the upper Paraná River
floodplain, Brazil, with the proposal of Pseudovancleaveus n. g. - Systematic Parasitology 54: 25-31.
GIOIA, I., CORDEIRO, N.S. & P.T. ARTIGAS (1988): Urocleidoides astyanacis n. sp. (Monogenea:
Ancyrocephalinae) from freshwater Characidians of the genus Astyanax. - Mem. Inst.
Oswaldo Cruz 83: 13-15.
GUIDELLI, G.M., TAKEMOTO, R.M. & G.C. PAVANELLI (2003): A new species of Kritskyia (Dactylogy-
ridae, Ancyrocephalinae), parasite of urinary bladder and ureters of Leporinus lacustris (Characi-
formes, Anostomidae) from Brazil. - Acta Scientiarum. Biological Sciences 25: 279-282.
GUTIÉRREZ, P.A. & D.M. SURIANO (1992): Ancyrocephalids of the genus Demidospermus suriano, 1983
(Monogenea) parasites from siluriform fishes in Argentina, with descriptions of three new
species. - Acta Parasitologica 37: 169-172.
HANEK, G., MOLNAR, K. & C.H. FERNANDO (1974): Three new genera of Dactylogyridae
(Monogenea) from freshwater fishes of Trinidad. - Parasit. 60: 911-913.
HARRIS, P.D. (1983): The morphology and life-cycle of the oviparous Oögyrodactylus farlowellae gen. et
sp. nov. (Monogenea, Gyrodactylidae). - Parasit. 87: 405-420.
HARRIS, P.D, & J. CABLE (2000): Gyrodactylus poeciliae n. sp. and G. milleri n. sp. (Monogenea:
Gyrodactylidae) from Poecilia caucana (STEINDACHNER) in Venezuela. - Systematic Parasitology
47(2): 79-85.
112 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
HARRIS, P.D. & A.M. LYLES (1992): Infections of Gyrodactylus turnbulli on guppies (Poecilia reticulata)
in Trinidad. - J. Parasitol. 78: 912-914.
JARA, C.A. & D.K. CONE (1989): Scleroductus yuncensi gen. et sp. n. (Monogenea) from Pimelodella
yuncensis (Siluriformes: Pimelodidae) in Peru. - Proc. Helminthol. Soc. Wash. 56: 125-127.
JARA, C., AN, L. & D. CONE (1991): Accessorius peruensis gen. et sp. n. (Monogenea: Gyrodactylidea)
from Lebiasina bimaculata (Characidae) in Peru. - J. Helminthol. Soc. Wash. 58: 164-166.
JOGUNOORI, W., KRITSKY, D.C. & J. VENKATANARASAIAH (2004): Neotropical Monogenoidea. 46. Three
new species from the gills of introduced aquarium fishes in India, the proposal of Heterotylus n. g.
and Diaphorocleidus n. g., and the reassignment of some previously described species of Urocleidoides
MIZELLE & PRICE, 1964 (Polyonchoinea: Dactylogyridae). - Systematic Parasitology 58: 115-124.
KOHN, A. (1990): Kritskyia moraveci n. g., n. sp. (Monogenea: Dactylogyridae) from the urinary
bladder and ureters of Rhamdia quelen (Quoy & Gaimard, 1824) (Pisces: Pimelodidae) in
Brazil. - Systematic Parasitology 17: 81-85.
KOHN, A. & I. PAPERNA (1964): Monogenetic trematodes from aquarium fishes. - Rev. Brasil. Biol.
24:145-149.
KOHN, A. & C.P. SANTOS (1989): Brazilian Monogenea. - List of species, hosts and geographical
distribution. - Rev. Brasil. Biol. 49(3): 809-815.
KOHN A., BAPTISTA-FARIAS, M.D. & S.C. COHEN (2000): Paranaella luquei gen. et sp. n. (Monogenea:
Microcotylidae), a new parasite of Brazilian catfishes. - Folia Parasitologica 47: 279-283.
KRITSKY, D.C. & W.A. BOEGER (1991): Neotropical Monogenea. 16. New species of oviparous
Gyrodactylidea with proposal of Nothogyrodactylus gen. n. (Oogyrodactylidae). - J. Helminthol.
Soc. Wash. 58: 7-15.
KRITSKY, D.C. & W.A. BOEGER (1995): Neotropical Monogenoidea. 26. Annulotrematoides amazonicus,
a new genus and species (Dactylogyridae: Ancyrocephalinae), from the gills of Psectrogaster
rutiloides (KNER) (Teleostei: Characiformes: Curimatidae) from the Brazilian Amazon. - Proc.
Biol. Soc. Wash. 108: 528-532.
KRITSKY, D.C.& W.A. BOEGER (1998): Neotropical Monogenoidea. 35. Pavanelliella pavanelli, a new
genus and species (Dactylogyridae: Ancyrocephalinae) from the nasal cavities of siluriform
fishes in Brazil. - J. Helminthol. Soc. Wash. 65: 160-163.
KRITSKY, D.C. & W.A. BOEGER (2002): Neotropical Monogenoidea. 41. New and previously
described species of Dactylogyridae (Platyhelminthes) from the gills of marine and
freshwater perciform fishes (Teleostei) with proposal of a new genus and a hypothesis on
phylogeny. - Zoosystema 24(1): 7-40.
KRITSKY, D.C. & T.H. FRITTS (1970): Monogenetic trematodes from Costa Rica, with the
proposal of Anacanthocotyle gen. n. (Gyrodactylidae: Isancistrinae). - Proc. Helminthol.
Soc. Wash. 37: 63-68.
KRITSKY, D.C. & P.A. GUTIÉRREZ (1998): Neotropical Monogenoidea. 34. Species of Demidospermus
(Dactylogyridae: Ancyrocephalinae) from the gills of pimelodids (Teleostei, Siluriformes) in
Argentina. - J. Helminthol. Soc. Wash. 65: 147-159.
KRITSKY, D.C. & P.D. LEIBY (1972): Dactylogyridae (Monogenea) from the freshwater fish, Astyanax
fasciatus (CUVIER), in Costa Rica, with descriptions of Jainus hexops sp. n. Urocleidoides costaricensis
and U. heteroancistrium combs. n. - Proc. Helminthol. Soc. Wash. 39: 227-230.
KRITSKY, D.C. & V.E. THATCHER (1974a): Monogenetic trematodes (Monophisthocotylea: Dactylo-
gyridae) from freshwater fishes of Colombia, South America. - J. Helminthol. 48: 59-66.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 113
KRITSKY, D.C. & V.E. THATCHER (1974b): New monogenetic trematodes from freshwater fishes of
Western Colombia with the proposal of Anacanthoroides gen. n. (Dactylogyridae). - Proc.
Helminthol. Soc. Wash. 43: 129-134.
KRITSKY, D.C. & V.E. THATCHER (1976): New monogenetic trematodes from freshwater fishes of
Western Colombia with the proposal of Anacanthoroides gen. n. (Dactylogyridae). - Proc.
Helminthol. Soc. Wash. 43: 129-134.
KRITSKY, D.C. & V.E. THATCHER (1977): Phanerothecium gen. nov. and Fundulotrema gen. nov.; two new
genera of viviparous Monogenoidea (Gyrodactylidae) with a description of P. caballeroi sp.
nov. and a key to the subfamilies and genera of the family. - Instituto Biológico de México,
Publ. Espec. 4: 53-60.
KRITSKY, D.C. & V.E. THATCHER (1983): Neotropical Monogenea. 5. Five new species from the aruanã,
Osteoglossum bicirrhosum VANDELLI, a freshwater teleost from Brazil, with the proposal of
Gonocleithrum n. gen. (Dactylogyridae: Ancyrocephalinae). - Proc. Biol. Soc. Wash. 96: 581-597.
KRITSKY, D.C. & V.E. THATCHER (1984): Neotropical Monogenea. 6. Five species of Diplectanum
(Diplectanidae) from freshwater teleosts, Plagioscion spp. (Scianidae), in Brazil. - Proc. Biol.
Soc. Wash. 97: 434-443.
KRITSKY, D.C., BOEGER, W.A. & M. JÉGU (1996 a): Neotropical Monogenoidea. 28. Ancyrocephali-
nae (Dactylogyridae) of piranha and their relatives (Teleostei, Serrasalmidae) from Brazil
and French Guiana: species of Notozothecium BOEGER and KRITSKY, 1988, and Mymarothecium
gen. n. - J. Helminthol. Soc. Wash. 63: 153-175.
KRITSKY, D.C., BOEGER, W.A. & M. JÉGU (1997a): Neotropical Monogenoidea. 29. Ancyrocephalinae
(Dactylogyridae) of piranha and their relatives (Teleostei, Serrasalmidae) from Brazil: species
of Amphithecium BOEGER and KRITSKY, 1988, Heterothecium gen. n. and Pithanothecium gen. n. - J.
Helminthol. Soc. Wash. 64: 25-54.
KRITSKY, D.C., BOEGER, W.A. & M. JÉGU (1997b): Neotropical Monogenoidea. 30. Ancyrocephali-
nae (Dactylogyridae) of piranha and their relatives (Teleostei, Serrasalmidae) from Brazil:
species of Calpidothecium gen. n., Calpidothecioides gen. n., Odothecium gen. n., and Notothecioides
gen. n. - J. Helminthol. Soc. Wash. 64: 208-218.
KRITSKY, D.C., BOEGER, W.A. & M. JÉGU (1998 ): Neotropical Monogenoidea. 31. Ancyrocephalinae
(Dactylogyridae) of piranha and their relatives (Teleostei, Serrasalmidae) from Brazil: species of
Notothecium BOEGER & KRITSKY, 1988, and Enallothecium gen. n. - J. Helminthol. Soc. Wash. 65: 31-49.
KRITSKY, D.C., BOEGER, W.A. & F. POPAZOGLO (1995): Neotropical Monogenoidea. 22. Variation in
Scleroductus species (Gyrodactylidea, Gyrodactylidae) from siluriform fishes of Southeastern
Brazil. - J. Helminthol. Soc. Wash. 62: 53-56.
KRITSKY, D.C., BOEGER, W.A. & V.E. THATCHER (1985): Neotropical Monogenea. 7. Parasites of the
pirarucu, Arapaima gigas (CUVIER), with description of two new species and redescription of
Dawestrema cycloancistrium PRICE & NOWLIN, 1967 (Dactylogyridae, Ancyrocephalinae). - Proc.
Biol. Soc. Wash. 97: 321-331.
KRITSKY, D.C., BOEGER, W.A. & V.E. THATCHER (1986): Neotropical Monogenea. 9. Status of Trinigyrus
HANEK, MOLNAR & FERNANDO, 1974 (Dactylogyridae) with descriptions of two new species
from loricariid catfishes from the Brazilian Amazon. - Proc. Biol. Soc. Wash. 99(3): 392-398.
KRITSKY, D.C., BOEGER, W.A. & V.E. THATCHER (1988): Neotropical Monogenea. 11. Rhinoxenus,
new genus (Dactylogyridae: Ancyrocephalinae) with descriptions of three new species from
the nasal cavities of Amazonian Characoidea. - Proc. Biol. Soc. Wash. 101(1): 87-94.
114 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
KRISKY, D.C., BOEGER, W.A. & L.R. VAN EVERY (1992): Neotropical Monogenoidea. 17. Anacantho-
rus MIZELLE and PRICE (Dactylogyridae, Anacanthorinae) from characoid fishes of Central
Amazon. - J. Helminthol. Soc. Wash. 59: 25-51.
KRITSKY, D.C., LEIBY, P.B. & R.J. KAYTON (1978): A rapid stain technique for the haptoral bars of
Gyrodactylus species (Monogenea). - J. Parasitol. 64(1): 172-174.
KRITSKY, D.C., MENDOZA-FRANCO, E.F. & T. SCHOLZ (2000): Neotropical Monogenoidea. 36.
Dactylogyrids from the gills of Rhamdia guatemalensis (Siluriformes: Pimelodidae) from
cenotes of the Yucatan Peninsula, Mexico, with proposal of Ameloblastella gen. n. and
Aphanoblastella gen. n. (Dactylogyridae: Ancyrocephalinae). - Comparative Parasitology
67: 76-84.
KRITSKY, D.C., THATCHER, V.E. & W.A. BOEGER (1986): Neotropical Monogenea. 8. Revision of
Urocleidoides (Dactylogyridae, Ancyrocephalinae). - Proc. Helminthol. Soc. Wash. 53: 1-37.
KRITSKY, D.C., THATCHER, V.E. & W.A. BOEGER (1987): Neotropical Monogenea. 10. Omothecium,
new genus (Dactylogyridae: Ancyrocephalinae) and two new species from the piranambu,
Pinirampus pirinampu (SPIX), (Siluriformes), in Brazil. - Proc. Biol. Soc. Wash. 100: 8-12.
KRITSKY, D.C., THATCHER, V.E. & W.A. BOEGER (1988): Neotropical Monogenea. 13. Rhinonastes
pseudocapsaloideum n. gen., n. sp. (Dactylogyridae, Ancyrocephalinae), a nasal parasite of
curimata, Prochilodus nigricans AGASSIZ (Cypriniformes, Prochilodontidae), in Brazil. - J.
Parasitol. 74: 695-698.
KRITSKY, D.C., THATCHER, V.E. & W.A. BOEGER (1989): Neotropical Monogenea. 15. Dactylogyridae
from the gills of Brazilian Cichlidae with proposal of Sciadicleithrum gen. n. (Dactylogyridae).
- Proc. Helminthol. Soc. Wash. 56: 128-140.
KRITSKY, D.C., THATCHER, V.E. & R.J. KAYTON (1979): Neotropical Monogenoidea. 2. The
Anacanthorinae PRICE, 1967, with the proposal of four new species of Anacanthorus MIZELLE
& PRICE, 1965, from Amazonian fishes. - Acta Amazonica 9: 355-361.
KRITSKY, D.C., THATCHER, V.E. & R.J. KAYTON (1980): Neotropical Monogenoidea. 3. Five new
species from South America with the proposal of Tereancistrum gen. n. and Trinibaculum gen. n.
(Dactylogyridae: Ancyrocephalinae). - Acta Amazonica 10: 411-417.
KRITSKY, D.C., VAN EVERY, L.R. & W.A. BOEGER (1996 b): Neotropical Monogenoidea. 27. Two new
species of Telethecium gen. n. from the nasal cavities of Central Amazonian fishes and a
redescription of Kritskyia moraveci KOHN, 1990 (Dactylogyridae, Ancyrocephalinae). - J.
Helminthol. Soc. Wash. 63: 35-41.
KRITSKY, D.C., VIDAL-MARTINEZ, V.M. & R. RODRIGUEZ-CANUL (1994): Neotropical Monogenoidea.
19. Dactylogyridae of cichlids (Perciformes) from the Yucatán Peninsula, with descriptions
ofthree new species of Sciadicleithrum KRITSKY, THATCHER & BOEGER, 1989. - J. Helminthol.
Soc. Wash. 61: 26-33.
MALABARBA, L.R. & I.M.L. ROSA (2003): Preface. - Neotropical Ichthyology 1: 1.
MAYES, M.A., BROOKS, D.R. & T.B. THORSON (1981): Potamotrygonocotyle tsalickisi, new genus and
species (Monogenea: Monocotylidae) and Paraheteronchocotyle amazonensis, new genus and
species (Monogenea: Hexabothriidae) from Potamotrygon circularis GARMAN (Chondrichthyes:
Potamotrygonidae) in Northwestern Brazil. - Proc. Biol. Soc. Wash. 94: 1205-1210.
MENDOZA-FRANCO, E.F. & V.M. VIDAL-MARTINEZ (2001): Salsuginus neotropicalis n. sp. (Monogenea:
Ancyrocephalinae) from the pike killifish Belonesox belizanus (Atheriniformes: Poeciliidae) from
Southeastern Mexico. - Systematic Parasitology 48: 41-45.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 115
MENDOZA-FRANCO, E.F., SCHOLZ, T. & V.M. VIDAL-MARTÍNEZ (1997): Sciadicleithrum meeki sp. n.
(Monogenea: Ancyrocephalinae) from the gills of Cichlasoma meeki (Pisces: Cichlidae) from
cenotes (= sinkholes) of the Yucatan Peninsula, México. - Folia Parasitológica 44: 205-208.
MIZELLE, J.D. (1936): New species of trematodes from the gills of Illinois fishes. American Midland
Naturalist 17: 785-806.
MIZELLE, J.D. & D.C. KRITSKY (1967): Unilatus gen. n., a unique Neotropical genus of Monogenea.
- J. Parasitol. 53: 1113-1114.
MIZELLE, J.D. & D.C. KRITSKY (1969a): Studies on monogenetic trematodes. XXXIX. Exotic species
of Monophisthocotylea with the proposal of Archidiplectanum gen. n. and Longihaptor gen. n. -
American Midland Naturalist 81: 370-386.
MIZELLE, J.D. & D.C. KRITSKY (1969b): Studies on monogenetic trematodes. XL. New species from
marine and freshwater fishes. - American Midland Naturalist 82: 417-428.
MIZELLE, J.D., KRITSKY, D.C. & J.W. CRANE (1968): Studies on monogenetic trematodes. XXXVIII.
Ancyrocephalinae from South America with the proposal of Jainus gen. n. - American
Midland Naturalist 80: 186-198.
MIZELLE, J.D. & C.E. PRICE (1964): Studies on monogenetic trematodes. XXVII. Dactylogyrid
species with the proposal of Urocleidoides gen. n. - J. Parasitol. 50: 579-584.
MIZELLE, J.D. & C.E. PRICE (1965). Studies on monogenetic trematodes. XXVII. Gill parasites of
the piranha with the proposal of Anacanthorus gen. n. - J. Parasitol. 51: 30-36.
MOLNAR, K., HANEK, G. & C.H. FERNANDO (1974): Ancyrocephalids (Monogenea) from freshwater
fishes of Trinidad. - J. Parasitol. 60: 914-920.
NASIR, P. (1983): Occurrence and significance of the monogenean Cycloplectanum americanum (PRICE,
1937) OLIVER, 1968, on a freshwater host. - J. Parasitol. 69: 957-962.
POPAZOGLO, F. & W.A. BOEGER (2000): Neotropical Monogenoidea. 37. Redescription of Gyrodacty-
lus superbus (SZIDAT, 1973) comb. n. and description of two new species of Gyrodactylus
(Gyrodactylidea: Gyrodactylidae) from Corydoras paleatus and C. ehrhardti (Teleostei: Siluri-
formes: Callichthyidae) of Southern Brazil. - Folia Parasitologica 47: 105-110.
PRICE, C.E. (1966): Urocleidus cavanaughi, a new monogenetic trematode from the gills of the
keyhole cichlid, Aequidens maroni (STEINDACHNER). - Bulletin of the Georgia Academy of
Science 24: 117-120.
PRICE, C.E. (1968): Diaccessorius, a new genus of Monogenea from the gills of an Amazon river
teleost. - Acta Biológica Venezuelica 6: 84-89.
PRICE, C.E. & W.A. BUSSING (1967): Monogenean parasites of Costa Rican fishes. Part I. Descriptions
of two new species of Cleidodiscus MUELLER, 1934. - Revista Parasitológica 28: 81-86.
PRICE, C.E. & W.A. BUSSING (1968): Monogenean parasites of Costa Rican fishes. Part II. Proposal
of Palombitrema heteroancistrium n. gen., n. sp. - Proc. Helminthol. Soc. Wash. 35: 54-57.
PRICE, C.E. & T.E. MCMAHON (1966): Monocleithrium, a new genus of Monogenea from an Amazon
River teleost. - Revista Parasitológica 27: 221-226.
PRICE, C.E. & W.J. NOWLIN (1967): Proposal of Dawestrema cycloancistrium n. gen., n.sp. (Trematoda:
Monogenea) from an Amazon River host. - Revista Parasitológica 28: 1-9.
PRICE, C.E. & N.G. ROMERO (1969): First account of a monogenetic trematode from Paraguay:
Amphocleithrium paraguayensis n. gen., n. sp. - Zoologische Jahrbücher 96: 449-452.
PRICE, C.E. & E.A. SCHLUETER (1967): Two new monogenetic trematodes from South America. - J.
Tennessee Acad. Sci. 42: 23-25.
116 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
PRICE, E.W. (1938): The monogenetic trematodes of Latin America. - Livro Jubilar do Prof. LAURO
TRAVASSOS, Rio de Janeiro (Brazil) 3: 407-413.
SURIANO, D.M. (1980): Notodiplocerus singularis gen. et sp. nov. (Monogenea: Ancyrocephalinae)
parásito de las branquias de Pseudocurimata gilberti (Pisces: Tetragonopteridae) de la Laguna de
Chascomus, República Argentina. - Neotropica 26: 131-143.
SURIANO, D.M. (1981): Andospira n. g., n. sp. (Monogenea, Ancyrocephalinae) a branchial parasite of
Pseudocurimata gilberti from Lake Chascomus, Argentina. - Neotropica 27: 67-78.
SURIANO, D.M. (1983): Demidospermus anus gen. nov. sp. nov. (Monogenea: Ancyrocephalinae)
parasita branquial de Loricaria (L) anus VALENCIENNES, 1840 (Pisces: Loricariidae) de la Laguna
de Chascomus, Provincia de Buenos Aires, Republica Argentina. - Neotropica 29: 169-172.
SURIANO, D.M. (1985): El género Unilatus MIZELLE y KRITSKY, 1967 (Monogenea: Ancyrocephal-
idae) parásito de Siluriformes (Pisces: Loricariidae) del Rio Negro, Manaus, Brasil. -
Neotropica 31: 163-175.
SURIANO, D.M. (1986a): Philocorydoras platensis gen. n. et. sp. n. (Monogenea: Ancyrocephalidae) from
Corydoras paleatus (Jenyns) (Pisces: Callichthyidae) in Laguna Chascomús - República Argenti-
na. - Helminthologia 23: 249-256.
SURIANO, D.M. (1986b): The genus Urocleidoides MIZELLE and PRICE, 1964 (Monogenea: Ancyroceph-
alidae). Anatomy and systematic position. Urocleidoides mastigatus sp. n. and U. travassosi (PRICE,
1934) MOLNAR, HANEK and FERNANDO, 1974 from Rhamdia sapo (VALENCIENNES, 1840)
EIGENMANN, 1888 and Pimelodella laticeps EIGENMANN, 1917 (Pisces: Siluriformes) in Laguna
Chascomus, República Argentina. - Physis (Buenos Aires), Secc. B, 44: 73-80.
SURIANO, D.M. & I.S. INCORVAIA (1995): Ancyrocephalid (Monogenea) parasites from siluriform
fishes from the paranean-platean ichthyogeographical province in Argentina. - Acta Parasito-
logica 40: 113-124.
SZIDAT, L. (1973): Morphologie und Verhalten von Paragyrodactylus superbus n. g., n. sp., Erreger eines
Fischsterben in Argentinien. - Angew. Parasit. 14: 1-10.
TAKEMOTO, R.M., LIZAURA, R. & G.C. PAVANELLI (2002): A new species of Kritskyia (Dactylogyridae,
Ancyrocephalinae) parasite of urinary bladder of Prochilodus lineatus (Prochilodontidae,
Characiformes) from the floodplain of the high Paraná river, Brazil. - Mem. Inst. Oswaldo
Cruz 97(3): 313-315.
THATCHER, V.E. & D.C. KRITSKY (1983): Neotropical Monogenoidea. 4. Linguadactyloides brinkmanni
gen. et sp. n. (Dactylogyridae: Linguadactyloidinae subfa. nov.) with observations on its
pathology in a Brazilian freshwater fish, Colossoma macropomum (CUVIER). - Proc. Helminthol.
Soc. Wash. 50: 305-311.
TURNBULL, E.R. (1956): Gyrodactylus bullatarudis n. sp. from Lebistes reticulatus PETERS with a study of
its life cycle. - Canadian Journal of Zoology 34: 583-594.
VAN EVERY, L.R. & D.C. KRITSKY (1992): Neotropical Monogenoidea. 18. Anacanthorus MIZELLE and
PRICE 1965 (Dactylogyridae, Anacanthorinae) of piranha (Characoidea, Serrasalmidae) from
the central Amazon, their phylogeny, and aspects of host-parasite coevolution. - J. Helm-
inthol. Soc. Wash. 59: 52-75.
VIDAL-MARTÍNEZ, V.M., SCHOLZ, T. & M.L. AGUIRRE-MACEDO (2001): Dactylogyridae of cichlid
fishes from Nicaragua, Central America, with descriptions of Gussevia herotilapiae sp. n. and
three new species of Sciadicleithrum (Monogenea: Ancyrocephalinae). - Comparative Parasitol-
ogy 68(1): 76-86.ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 117
4
TREMATODA (DIGENEA)
I. Definition and morphology
The digenetic trematodes are endoparasitic platyhelminths having complex life-cycles. All
are hermaphroditic with the exception of some blood inhabiting forms (Schistosoma-
tidae) and some tissue invaders found in marine fishes (Didymozoidae). All trematode
species reported so far from Neotropical freshwater fishes have functional male and
female organ systems in each individual. Many fish trematodes are less than one
millimeter in length, but most of those treated here would fall into the 2 to 20 millimeter
size range. Although considered to be “flatworms”, not all species are dorso-ventrally
flattened. Some are indeed flat and leaf-like but others are cylindrical, spherical or
pyriform. The body is usually provided with oral and ventral suckers and the external
surface (tegument) may be spined.
The female reproductive system consists of: an ovary; oviduct; yolk glands (vitellar-
ia); oötype; Mehlis’s gland; Laurer’s canal and seminal receptacle (sometimes absent).
Some species also have the distal end of the uterus modified into a muscular tube for
reception of the male copulatory organ (cirrus). This functional vagina in trematodes is
called a metraterm.
The male system includes: testes (usually two but there may be from one to many
testes present according to the species); vas deferens; seminal vesicle and a cirrus and
cirrus sac (which are sometimes absent). The number, size, form and position of the
reproductive organs are important in the classification and identification of these worms.
The nature of the digestive system is also important in the systematics of trematodes.
This system usually consists of: a mouth and oral sucker; prepharynx; pharynx; esophagus
and two intestinal branches called ceca or crura. The digestive system is normally incomplete
in that the intestinal branches end blindly. There are some species, however, in which the
crura open to the exterior through anal pores or open into the excretory bladder.
II. Life-cycle and transmission
Spermatozoa produced in the testes reach the seminal vesicle by way of tubules (vasa
efferentia and vas deferens). As in the case in most hermaphroditic invertebrates,
copulation consists of a mutual exchange of sperm cells with each individual inserting the
118 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
male organ (cirrus) into the female pore (uterine pore or metraterm) of the other. The
male cells make their way the length of the uterus and are stored in the seminal receptacle,
to be used as needed.
Female cells from the ovary pass one at a time down the oviduct to a muscular
organ called the oötype. There the ovum is fertilized by a sperm from the seminal
receptacle and surrounded by yolk cells from the vitelline glands. Shell material is
provided by the yolk glands as well in the form of a liquid which quickly hardens
around the gamete and yolk cells. Mehlis’ gland, which surrounds the oötype, is thought
to produce a catalytic agent to harden the shell. The finished capsule (egg) is slowly
carried down the length of the uterus and eventually expelled into the environment
through the uterine pore (common genital pore).
Adult trematodes live in the digestive tract, hollow organs, circulatory system or
subcutaneous connective tissue of vertebrates. Copulation and egg production
(sexual reproduction) is carried out in these hosts. The eggs are carried to the exterior
environment with the feces or urine of the host and they usually hatch shortly after
reaching water. Some fish trematodes, especially Paramphistomidae, are ovovivipa-
rous and in these forms, the egg shell is reabsorbed in the uterus and larvae are
liberated from the uterine pore. The first larval stage (miracidium) is ciliated and
swims actively in search of an appropriate species of snail. These larvae cannot feed
so they die in a few hours if they do not reach a suitable host. Upon finding a snail,
the miracidium penetrates the body wall by means of its anterior penetration glands
and makes its way to the digestive gland (hepatopancreas). There it loses its cilia, and
most internal structure and assumes a sac-like form (sporocyst). Within the sporocyst,
the third larval stages (rediae) are produced from germinative cells. Several of these
larvae are produced within the sporocyst which eventually ruptures to free them
within the snail’s digestive gland. The rediae in turn produce larvae called cercariae.
These leave the rediae through birth pores and abandon the snail to seek a second
intermediary host, or to encyst on vegetation. Cercariae do not feed although they
normally have a mouth and digestive system. They have enough stored energy to
swim actively for several hours after which they die if they do not find a suitable host
or a site for encystment. Most cercariae have a posterior tail-like projection to
facilitate swimming. During encystment, the tail is lost and the resultant infective
larva is termed a metacercaria. In some cases cercariae may invade the definitive host
directly. This is the normal means of transmission of blood inhabiting species
(Sanguinicolidae) and of tissue forms (Didymozoidae).
Although little work has been done on the life-cycles of Neotropical fish trematodes,
it is possible to deduce what the mode of transmission must be based on studies done
elsewhere. With the exception of the two families mentioned above, all fish trematodes
enter the host as encysted metacercariae in the food. The families Acanthostomidae,
Allocreadiidae, Fellodistomidae, Heterophyidae and Opisthorchiidae are transmitted to
piscivorous species in the tissues of smaller fishes. Angiodictyidae, Haploporidae,
Paramphistomidae and Zonocotylidae reach their fish hosts in aquatic plants. Echinosto-
matidae are probably transmitted to fish that devour the snail intermediate host, and
Bucephalidae to those that eat bivalve mollusks.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 119
III. Pathology
The pathogenicity of trematodes to their fish hosts varies in accordance with a number of
factors which can be summarized as follows:
1) A trematode that penetrates tissues will be more pathogenic than one that lives in
the intestinal lumen or the interiors of other hollow organs.
2) A trematode that is large in relation to the host or organ invaded will be more
pathogenic than a small trematode would be in the same host or organ.
3) Pathology in the host is usually proportional to the number of trematodes present
(intensity of infection).
4) Trematodes that migrate within the host cause more damage than those remain in
one location.
5) Trematode eggs passing through tissues (Sanguinicolidae) can cause more host
reaction that the adults producing the eggs.
6) Host reaction to tissue invading trematodes is initially an inflammatory one, with
infiltration of lymphocytes, and is followed by the fibrous encapsulation of the
invader. Once the encapsulation process is finished, danger to the host ends.
7) Host reaction to trematodes in the intestinal lumen is also of the inflammatory
type, but is generally limited to the point of fixation of the worms.
8) Trematodes within tubules (such as the bile and pancreatic ducts) can cause
distension of the lumen and hyperplasia of the walls and decrease their flow.
Trematode cercariae that invade the skin of fishes and become encysted there can
become visible to the naked eye if the fish host concentrates pigment cells around them.
This condition is wide-spread and is known as “black-spot disease”. In Amazonian fish,
we have observed this phenomenon in Hoplias malabaricus and Semaprochilodus insignis and it
no doubt occurs in other species as well. Although the presence of these metacercariae in
the skin does not seem to impairthe health of the fish, the black spots are sometime so
numerous that they make the fish unappealing to the consumer. In the Neotropics, the
black spots are usually caused by Acanthostomidae or Heterophyidae which mature in
crocodilians, piscivorous birds or predatory fish. A somewhat similar condition is known
internationally as “yellow-spot disease”. The yellow spots are caused by the yellow
coloration of the metarcercariae of the family Clinostomidae. In the Amazon, we have
found the genera Clinostomum and Odhneriotrema to be responsible. The former matures in
birds and the latter in crocodilians.
Another sort of “yellow-spot disease” is found in the Amazonian fish, Plagioscion
squamosissimus, which is a freshwater relative of the Atlantic weakfish. This condition is
caused by adults of Brasicystis bennetti THATCHER, 1979, of the family Didymozoidae (Figs.
4-3 & 4-47). These worms live in the subcutaneous tissues with their slender anterior ends
projecting through small holes that they maintain open. As they mature, their entire
bodies become packed with thousands of small egg capsules which have a yellowish hue.
These masses of eggs can be seen through the skin as yellowish spots or blotches which
are as much as two centimeters in diameter. The most common site for penetration is the
inner surface of the gill covers, but the worms can also be found in the gill filaments, fins,
eyes and generally distributed throughout the skin of the body. Some fish become so
120 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
heavily infected as to have an overall yellowish appearance. Local fishermen in the
Brazilian Amazon have a special name for such fish and many regard them as a different
species. In some parts of the Amazon, prevalence rates reach 10 % but the worms do not
seem to inconvenience the fish.
Another world wide problem in fish caused by larval trematodes is known as
“eye fluke disease”. Infected fish can be seen to have larvae moving about within the
eye. There is usually no inflammatory reaction, but the presence of the worms
impedes the vision of the fish. These larvae are less well developed than metacercar-
iae and do not become encysted. They are known as mesocercariae or diplostomula
and usually belong to the genera Diplostomum or Alaria of the superfamily Strigeoidea.
Diplostomula are much flattened and have the general appearance of the sole of a
tennis shoe (Figs. 4-48 & 4-49).
Mesocercariae of species that infect fishes can be found in any organ, but they tend
to concentrate in the eyes and optic nerves. In these sites, they can blind the fish and make
it easy prey for piscivorous birds. Thus, the parasite actively participates in the completion
of its life-cycle and the passage from the second intermediate to the definitive host. Such
larvae have been reported from the human eye (ASHTON et al. 1969). In human beings,
these migrating larvae can cause extensive tissue destruction, anaphylactic shock and
death if present in large numbers (FREEMAN et al. 1976).
THATCHER & VARELLA (1980) found that larval trematodes were involved with
branchial carcinoma in an Amazonian fish, Chaetobranchus semifasciatus. In this fish a large
primary neoplasm (27 x 18 x 12 mm) and a small satellite tumor (3 mm in diameter) were
found attached to the first branchial arch (Fig. 4-51). These were both dense tumors
covered by a smooth epithelium and containing blood vessels, collagen fibers, pigment
cells and irregular masses of cartilage. In these two tumors, there were no trematode
larvae, but in each of 19 additional tumorous growths in the gill filaments there was a
single metacercaria of Ascocotyle sp. (Figs. 4-52 & 4-53). In four of these tumoroids, the gill
filaments showed repetitious growth with parts of filaments projecting in varios
directions (Fig. 4-54).
IV. Prevention and treatment
Prevention of trematode infection in fish consists of eliminating intermediate hosts in the
environment. This is easy enough to do in aquaria and small intensive pisciculture
operations but frequently proves to be impossible in larger tanks and ponds. Introducing
snails and aquatic plants collected in nature to aquaria with tropical fish can be hazardous
and should be avoided. For a balanced aquarium, snails and plants grown in aquaria
should be utilized.
If no infected snails are present in an aquatic system, black-spot and yellow-spot
diseases can not occur. Of course, healthy snails can become infected at any time that
vertebrate feces containing trematode eggs enter the system. For example, in outdoor
ponds birds may defecate into the water and initiate an infective cycle. In an aquarium, a
fish carrying adult trematodes can potentially infect all the others if snails are present.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 121
The feeding of wild caught minnows to captive predatory fish should be avoided
since such small fish frequently contain encysted metacercariae. If pieces of fish or
crustaceans are used as food in aquaria or ponds, such material should be deep-frozen for
at least 48 hours before use to kill any metacercariae present.
No treatment is possible for encysted metacercariae but adult trematodes can be
removed from the intestinal tracts of fish with Di-N-Butyl Tin Oxide which can be mixed
with the ration at 0.3 % of body weight administered for from one to five days.
V. Collection and study methods
Trematodes are best collected alive from freshly killed fish. To do so, wild caught fish can
be brought in alive and maintained in aquaria until used. If they are deprived of food for
10-24 hours prior to necropsy, their digestive tracts will be nearly clean and the trematodes
will be easier to see. This is especially important for bottom feeders that ingest sand since
some trematodes are about the same size as sand grains. If it is not possible to transport
the fish alive, they may be brought in on ice and kept in the refrigerator. Trematodes will
often remain alive for several hours in cool fish. The hosts should not be deep-frozen,
however, as this will not only kill the worms but damage them as well. Living trematodes
are easier to find than dead ones for the simple reason that they move.
Since many fish trematodes are less than one millimeter in length, some skill and care
are required to find them in the host viscera. All hollow organs (stomach, intestine, swim
bladder, heart, etc.) should be opened with scissors and washed in finger bowls by
enthusiastic agitation. After removing the washed organs from the bowls, the dirty water
should be slowly decanted and gradually replaced by clean water. This process of hand
sedimentation should be repeated until the water in the bowl is clear and the floating
debris has been eliminated. In this way, it is possible to concentrate the live worms in the
bottom of the dish where they can be found by careful examination with a dissecting
microscope.
Trematodes should be killed in a relaxed position before fixation and this can best be
accomplished by the application of gentle heat. A rapid method is to place one, or several
specimens, on a slide in water with a coverglass in place and pass a lighted match several
times underneath. When the worms no longer show movement, they can be fixed in place
with AFA fixative (85 parts of 85 % alcohol: 10 parts of commercial formaldehyde: 5
parts of glacial acetic acid). To do this, it is necessary to place drops of AFA on one side
of the coverglass while withdrawing the water from the other side with filter paper. If
large numbers of trematodes must be fixed in a limited time, they can be placed in water
and left in an embedding oven for 10-15 minutes. After they no longer move, they can be
transferred directly to AFA or fixed on slides with a little coverglass pressure.
After fixation in AFA for several hours, permanentpreparations for study should be
prepared by means of the following procedure:
1. Wash the specimens in running water for 30 minutes to remove the fixative.
2. Place the worms in a staining solution containing 3 drops of Mayer’s Carmalum
stock solution to each 10 cm3 of water. Leave them in this stain until they are wine
122 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
colored throughout (the time varies from 10 minutes to 10 hours depending on
the size of the worms).
3. Pass the worms to a destaining solution (35 % alcohol to which hydrochloric acid
has been added in the ratio of 6 drops per liter). Leave them in destain until the
bodies are seen as pale pink and the organs are still wine or red (the time will vary
from a few seconds to several hours depending on size).
4. After destaining, dehydrate the worms gradually by serial passage through alcohol
at 50, 70, 85, 95 and 100 %. They should be left for a minimum of 10 minutes in
each alcohol. It is advisable to leave them for 30 minutes or more in the absolute
alcohol to insure complete dehydration.
5. After dehydration, the worms should be passed to a clearing agent such as methyl
salicylate or xylol.
6. The worms should clear completely in a few minutes and they can then be
mounted directly in Canada balsam, Clarite, Piccolyte or other similar mounting
media.
Mayer’s Carmalum stock solution can be mixed in the following way:
Mix 1 g of carminic acid stain, 10 g of alum and 200 cm3 of distilled water in a
beaker and boil for 30 minutes. Afterwards, filter the stain and store in the
refrigerator.
If carminic acid stain is unavailable, it can be made in the laboratory as follows:
1. Mix 10 g of carmine stain with 100 cm3 of glacial acetic acid in a beaker.
2. Heat the beaker to the boiling point and then let it cool.
3. Filter the liquid and save the material that sticks to the filter paper.
4. Scrape the material off of the filter paper and heat it in a beaker to dry it. This will
evaporate the excess acetic acid. The material should be warmed carefully while
stirring. This drying will eventually produce a dry dark red powder without the
odor of acetic acid. This resultant powder is carminic acid stain and can be used
as above to make Mayer’s Carmalum.
VI. Identification and keys
Trematodes have few hard parts other than the circumoral spines found in certain genera.
Identification is therefore based mainly on the number, size, form and position of the
suckers, pharynx and internal organs. It is necessary to distinguish the ovary, testes,
viteline glands and cirrus sac and note their position in the body and in relation to each
other. One must also be able to tell the difference between a cirrus sac and a
hermaphroditic sac. In a well stained specimen, it will be possible to see the uterus
entering the proximal end of the hermaphroditic sac. There may be visible eggs within the
sac as well. If the structure is a cirrus sac, the uterus will be seen to have an opening to the
exterior in common with it. Figures 4-1 to 4-3 will serve as guides to the identification of
trematode organs.
A
BLA
 V
ol. 1 – Thatcher: A
m
azon Fish Parasites 123
Key to the Neotropical freshwater fish trematodes
I. Anterior attachment organ a rhynchus; mouth ventral; gut saccular .............................................................................................. Bucephalidae
A. Rhynchus oval, without projections ................................................................................................................................Bellumcorpus (Fig. 4-4)
B. Rhynchus with cap, opening subterminal ................................................................................................................................... Pararhipidocotyle
C. Rhynchus plug or funnel-shaped.
1. Mouth in anterior third of body; gut long ............................................................................................................ Paurorhynchus (Fig. 4-5)
2. Mouth in middle third of body; gut short .............................................................................................................Prosorhynchus (Fig. 4-6)
D. Rhynchus sucker-like ................................................................................................................................ Glandulorhynchus (Figs. 4-91 & 4-92)
II. Anterior attachment organ a sucker (when present); mouth anterior, terminal or subterminal; gut divided into two crura.
A. Oral sucker absent; parasites of circulatory system.................. Sanguinicolidae ...................................................Sanguinicola (Fig. 4-32)
B. Oral sucker present; ventral sucker (acetabulum) absent.
1. Body divided into slender anterior and swollen posterior portions; parasites of subcutaneous tissues ..........................................
....................................................................................................... Didymozoidae .......................................... Brasicystis (Figs. 4-3 & 4-47)
2. Body undivided; parasites of digestive tract ...................................................................................................................... Angiodictyidae
a. Body without posterior projections; cirrus sac small ......................................................................................... Curumai (Fig. 4-44)
b. Body with posterior projections; cirrus sac absent.
1) Body with 4 posterior projections; esophageal bulb absent ................................................................... Denticauda (Fig. 4-45)
2) Body with 2 posterior projections; esophageal bulb present ..........................................................Pseudoparabaris (Fig. 4-46)
C. Both suckers present; acetabulum at or near posterior extremity ......................................................................................... Paramphistomata
1. Acetabulum subterminal, with or without horizontal ridges on floor.
a. Acetabulum subterminal, with ridges on floor.
1) One testis present ........................................................................................................................................................ Zonocotylidae
a) Vitelline glands compact, subspherical .................................................................................................. Zonocotyle (Fig. 4-41)
b) Vitelline glands compact, V-shaped .................................................................................................. Zonocotyloides (Fig. 4-42)
2) Two testes present .............................................. Cladorchiidae ...................Dadayius (Figs.4-28, 4-65 A-B, 4-73 to 4-76 & 4-84)
b. Acetabulum without ridges on floor.
1) One testis present ................................................................................................................................... Pseudodiplodiscus (Fig. 4-29)
2) Two testes present.
124 A
BLA
 V
ol. 1 – Thatcher: Parásitos de Peces A
m
azónicos
a) Oral diverticula absent; testes tandem..............................................................................................Travassosinia (Fig. 4-27)
b) Oral diverticula absent; testes parallel ..........................................................................................Micramphistoma (Fig. 4-95)
c) Oral diverticula small, within wall of oral sucker.
(1) Anterior extremity with collar-like expansion.
(a) Testes parallel ...................................................................................................................................Kalitrema (Fig. 4-39)
(b) Testes tandem, compact ..................................................................................................... Pronamphistoma (Fig. 4-96)
(c) Testes tandem, lobate .........................................................................................................Anavilhanatrema(Fig. 4-97)
(2) Anterior extremity without collar-like expansion.
(a) Vitellline glands compact ....................................................................................................... Colocladorchis (Fig. 4-40)
(b) Vitelline glands follicular .........................................................................................Pseudocladorchis (Figs. 4-30, 4-62)
d) Oral diverticula large, external to wall of oral sucker.
1) Collar-like expansion present.
a) Testes diagonal, subspherical .................................................................................................. Curimatrema (Fig. 4-64)
b) Testes tandem, lobate ...................................................................................................... Gammamphistoma (Fig. 4-57)
2) Collar-like expansion absent.
a) Tegument papillate ventrally.
(1) Five pairs of muscular puckers present laterally ......Annelamphistoma (Figs. 4-67 A-C, 4-77 to 4-79, 4-89)
(2) One pair of muscular puckers present near oral sucker. ...................................... Inpamphistoma (Figs. 4-66)
b) Tegument smooth.
(1) Testes parallel ................................................................................................................... Betamphistoma (Fig. 4-55)
(2) Testes tandem.
(a) Large genital sucker present ............................................................................... Pacudistoma (Fig. 4-60 A-C)
(b) Acetabulum with papillae ....................................................................................Myleustrema (Fig. 4-59 A-B)
(c) Body rim folded ventrally ........................................................................... Alphamphistoma (Fig. 4-61 A-B)
(d) Acetabulum with posterior notch on rim ................................................... Zetamphistoma (Fig. 4-63 A-B)
(e) Vitellaria extensive; testes large, lobate ...............................................................Deltamphistoma (Fig. 4-56)
(f) Vitellaria less extensive; testes small, spherical .............................................. Doradamphistoma (Fig. 4-99)
D. Both suckers present; acetabulum not near posterior extremity.
1. Nine testes present ........................................................................... Cryptogonimidae ......................................... Iheringtrema (Fig. 4-22)
A
BLA
 V
ol. 1 – Thatcher: A
m
azon Fish Parasites 125
2. One testis present; hermaphroditic bursa present ...............................................................................................................Haploporidae
a. Crura fused together forming single bi-lobed sac ...............................................................................................................Unicoelium
b. Crura short, not reaching level of testis.
1) Acetabulum pre-equatorial ........................................................................................................Chalcinotrema (Figs. 4-26 & 4-33)
2) Acetabulum post-equatorial .................................................................................................................. Lecithobotrioides (Fig. 4-94)
c. Crura longer reaching to level of testis.
1) Vitelline follicles extensive ..................................................................................................................... Lecithobotrioides (Fig. 4-31)
2) Vitelline follicles of limited extent..
(a) Testis elongate .................................................................................................................................Megacoelium (Fig. 4-24 A-B)
(b) Testis subspherical ...................................................................................................... Saccocoelioides (Figs. 4-34, 4-35 & 4-43)
d. Crura long, far surpassing testis posteriorly.
1) Hermaphroditic bursa small .................................................................................................................. Paralecithobotrys (Fig. 4-36)
2) Hermaphroditic bursa large ......................................................................................................................... Rondotrema (Fig. 4-93)
3. One testis present; cirrus sac present .................................................................................................................................... Monorchiidae
a. Cirrus sac nearly half as long as body .............................................................................. Genolopa magnacirrus (Figs. 4-70 & 4-72)
b. Cirrus sac small, barely surpassing acetabulum.
1) Testis near posterior extremity .......................................................................................... Sphericomonorchis spinulosus (Fig. 4-69)
2) Testis far from posterior extremity ..........................................................................Paraproctotrema delicata (Figs. 4-68 & 4-71)
4. Two testes present; cirrus sac present or absent.
a. Ovary posterior to testes.
1) Vitelline glands posterior to ovary.
a) Vitelline glands near posterior extremity ............................................................................................................. Halipegidae
(1) Vitelline glands of large follicles grouped together into two masses ........................................Halipegus (Fig. 4-21)
(2) Vitelline follicles smaller, in two groups .......................................................................................................... Gonocercella
b) Vitelline glands anterior to acetabulum ......................................................................................................... Fellodistomidae
(1) Testes intercecal ....................................................................................................................................Antorchis (Fig. 4-13)
(2) Testes extracecal ....................................................................................................................................... Bacciger (Fig. 4-98)
b. Ovary between testes.
1) Mouth surrounded by papillae .......................................... Cryptogonimidae .............................Palaeocryptogonimus (Fig. 4-23)
126 A
BLA
 V
ol. 1 – Thatcher: Parásitos de Peces A
m
azónicos
2) Mouth simple ........................................................................ Callodistomidae ......................................... Prosthenhystera (Fig. 4-7)
c. Ovary anterior to testes.
1) Oral sucker provided with spines.
a) Vitelline glands lateral to acetabulum ...................... Heterophyidae ....................................................Parspina (Fig. 4-20)
b) Vitelline glands posterior to acetabulum ................. Acanthostomidae ..................................... Acanthostomum (Fig. 4-1)
2) Oral sucker provided with spinous collar ....................... Echinostomatidae ................................... Caballerotrema (Fig. 4-16)
3) Oral sucker with membranous extensions ..................... Allocreadiidae.
a) Oral sucker with lobes ....................................................................................................................... Crepidostomum (Fig. 4-10)
b) Oral sucker with cap-like structure ..................................................................................................... Creptotrema (Fig. 4-11)
4) Oral sucker simple.
a) Vitelline glands consisting of two compact masses in mid-body region .................................................. Gorgoderidae
(1) Vitelline masses elongate ................................................................................................................. Dendrorchis (Fig. 4-19)
(2) Vitelline masses smaller than testes ........................................................................................Amazonadistoma (Fig. 4-2)
(3) Vitelline masses larger than testes .........................................................................................Phyllodistomoides (Fig. 4-25)
b) Vitelline glands consisting of follicles in limited fields posterior to acetabulum.
(1) Testes near posterior extremity; suckers subequal.
(a) Prepharynx long ............................................... Opisthorchiidae .............................................. Witenbergia (Fig. 4-8)
(b) Prepharynx short ............................................. Allocreadiidae ............................................ Procaudotestis (Fig. 4-14)
(2) Testes near posterior extremity; acetabulum much smaller than oral sucker ..............................................................
................................................................................... Opisthorchiidae ................................................ Cladocystis (Fig. 4-9)
(3) Testes in posterior half of body; acetabulum much larger than oral sucker; pharynx large, with finger-like
anterior extensions ................................................. Fellodistomidae ........................................... Kalipharynx (Fig. 4-15)
c) Vitelline glands consisting of follicles which are large and limited to two fields lateral to acetabulum ......................
.......................................................................................... Allocreadiidae .........................................Magnivitellinum (Fig. 4-17)
d) Vitelline glands consisting of follicles that are small and extensive, especially in posterior half of body.
(1) Lateral vitelline fields uniting anteriorly and posteriorly to acetabulum ......................................................................
................................................................................... Allocreadiidae ................................................. Crassicutis (Fig. 4-18)
(2) Lateral vitelline fields not uniting anteriorly ...... Lepocreadidae ................................................Eocreadium (Fig. 4-12)
A
BLA
 V
ol. 1 – Thatcher: A
m
azon Fish Parasites 127
Clave para identificación de Tremátodos, parásitos de peces Neotropicales
I. Organo de fijación anterior, rincodeo; boca ventral; intestino en forma de saco ..................................................................... Bucephalidae
A. Rincodeo oval, sin proyecciones .....................................................................................................................................Bellumcorpus (Fig. 4 -4)
B. Rincodeo con tapa, abertura subterminal .................................................................................................................................. Pararhipidocotyle
C. Rincodeo en forma de tapón o embudo.
1. Boca en el tercio anterior del cuerpo; intestino largo ......................................................................................... Paurorhynchus (Fig. 4-5)
2. Boca en el tercio central del cuerpo; intestino corto ...........................................................................................Prosorhynchus (Fig. 4-6)
D. Rincodeo en forma de ventosa .............................................................................................................. Glandulorhynchus (Figs. 4-91 & 4-92)
II. Organo de fijación anterior, una ventosa (cuando presente); boca anterior, terminal o subterminal; intestino dividido en 2 ramales
A. Ventosa oral ausente; parásitos del sistema circulatorio ................. Sanguinicolidae .............................................Sanguinicola (Fig. 4-32)
B. Ventosa oral presente; ventosa ventral (acetábulo) ausente.
1. Cuerpo dividido en porción anterior delgada y porción posterior hinchada; parásitos de tejidos subcutáneos. ............................
.............................................................................................................. Didymozoidae ................................... Brasicystis (Figs. 4-3 & 4-47)
2. Cuerpo no dividido; parásitos del tracto digestivo ........................................................................................................... Angiodictyidae
a. Cuerpo sin proyecciones posteriores; saco del cirro pequeño ......................................................................... Curumai (Fig. 4-44)
b. Cuerpo con proyecciones posteriores; saco del cirro ausente.
1) Cuerpo con 4 proyecciones posteriores; bulbo esofágico ausente ....................................................... Denticauda (Fig. 4-45)
2) Cuerpo con 2 proyecciones posteriores; bulbo esofágico presente ...............................................Pseudoparabaris (Fig. 4-46)
C. Ambas ventosas presentes; acetábulo en o cerca de la extremidad posterior ............................................................... Paramphistomata
1. Acetábulo subterminal, con o sin surcos horizontales en el piso.
a. Acetábulo subterminal, con surcos en el piso.
1) Un teste presente ........................................................................................................................................................ Zonocotylidae
(a) Glándulas vitelinas compactas, subesféricas ......................................................................................... Zonocotyle (Fig. 4-41)
(b) Glándulas vitelinas compactas, forma de V ................................................................................... Zonocotyloides (Fig. 4-42)
2) Dos testes presentes ...............................................Orchiidae ...................... Dadayius (Figs. 4-28, 4-65 A-B, 4-73 a 4-76 & 4-84)
b. Acetábulo sin surcos en el piso.
1) Um teste presente ................................................................................................................................... Pseudodiplodiscus (Fig. 4-29)
2) Dos testes presentes.
128 A
BLA
 V
ol. 1 – Thatcher: Parásitos de Peces A
m
azónicos
(a) Divertículo oral ausentes; testes uno delante del otro .................................................................. Travassosinia (Fig. 4-27)
(b) Divertículo oral ausentes; testes paralelos ...................................................................................Micramphistoma (Fig. 4-95)
(c) Divertículo oral pequeño, dentro de la pared de la ventosa oral
(1) Extremidad anterior con expansión en forma de collar.
a) Testes paralelos ................................................................................................................................Kalitrema (Fig. 4-39)
b) Testes uno delante del otro, compactos .......................................................................... Pronamphistoma (Fig. 4-96)
c) Testes uno delante del otro, lobulados ...........................................................................Anavilhanatrema (Fig. 4-97)
(2) Extremidad anterior sin expansión en forma de collar
a) Glándulas vitelinas compactas .............................................................................................. Colocladorchis (Fig. 4-40)
b) Glándulas vitelinas foliculares ................................................................................Pseudocladorchis (Figs. 4-30, 4-62)
(d) Divertículos orales grandes, externo a la pared de la ventosa oral.
(1) Expansión en forma de collar presente.
a) Testes diagonal, sub-esférico .................................................................................................. Curimatrema (Fig. 4-64)
b) Testes uno detrás del otro, lobulado ............................................................................ Gammamphistoma (Fig. 4-57)
(2) Expansión en forma de collar ausente.
a) Tegumento con papilas ventrales.
1. Cinco pares de pliegues musculares laterales ............Annelamphistoma (Figs. 4-67 A-C, 4-77 a 4-79, 4-89)
2. Un par de pliegues musculares cerca de la ventosa oral ......................................... Inpamphistoma (Fig. 4-66)
b) Tegumento liso.
1. Testes paralelos ................................................................................................................Betamphistoma (Fig. 4-55)
2. Testes uno detrás del otro.
(a) Ventosa genital grande presente ........................................................................ Pacudistoma (Fig. 4-60 A-C)
(b) Acetábulo con papilas ..........................................................................................Myleustrema (Fig. 4-59 A-B)
(c) Borde del cuerpo doblado ventralmente ................................................. Alphamphistoma (Fig. 4-61 A-B)
(d) Acetábulo con ranura posterior en el borde .............................................. Zetamphistoma (Fig. 4-63 A-B)
(e) Vitelaria extensa; testes grandes, lobulados .......................................................Deltamphistoma (Fig. 4-56)
(f) Vitellaria menos extensa; testes pequeños, esféricos .................................... Doradamphistoma (Fig. 4-99)
D. Ambas ventosas presentes; acetábulo alejado de la extremidad posterior.
1. Nueve testes presentes ..................................................................... Cryptogonimidae ......................................... Iheringtrema (Fig. 4-22)
A
BLA
 V
ol. 1 – Thatcher: A
m
azon Fish Parasites 129
2. Un teste presente; bursa hermafrodita presente ..................................................................................................................Haploporidae
a. Ramales intestinales fusionados formando un único saco bilobado ................................................................................Unicoelium
b. Ramos intestinales cortos, no alcanza el nivel de los testes.
(1) Acetábulo pre-ecuatorial ............................................................................................................Chalcinotrema (Figs. 4-26 & 4-33)
(2) Acetábulo post-ecuatorial ...................................................................................................................... Lecithobotrioides (Fig. 4-94)
c. Ramos intestinales largos alcanzando el nivel de los testes.
(1) Folículos vitelinos extensos ................................................................................................................... Lecithobotrioides (Fig. 4-31)
(2) Folículos vitelinos con extensión limitada.
(a) Teste alargado ..................................................................................................................................Megacoelium (Fig. 4-24 A-B)
(b) Teste sub esférico ....................................................................................................... Saccocoelioides (Figs. 4-34, 4-35 & 4-43)
d. Ramos intestinales largos, pasando con largueza los testes posteriomente.
1) Bursa hermafrodita pequeña ................................................................................................................. Paralecithobotrys (Fig. 4-36)
2) Bursa hermafrodita grande ........................................................................................................................... Rondotrema (Fig. 4-93)
3. Un teste presente, saco del cirro presente ............................................................................................................................ Monorchiidae
a. Saco del cirro aproximadamente la mitad del largo del cuerpo .................................. Genolopa magnacirrus (Figs. 4-70 & 4-72)
b. Cirro pequeño, apenas pasando el acetábulo.
1) Teste cerca de la extremidad posterior ............................................................................ Sphericomonorchis spinulosus (Fig. 4-69)
2) Teste alejado de la extremidad posterior ................................................................ Paraproctotrema delicata (Figs. 4-68 & 4-71)
4. Dos testes presentes; saco del cirro presente o ausente.
a. Ovario posterior a los testes.
1) Glándulas vitelinas posteriores al ovario.
a) Glándulas vitelinas cerca de la extremidad posterior .................................................................................................. Halipegidae
(1) Glándulas vitelinas de grandes folículos agrupadas en dos masas ............................................Halipegus (Fig. 4-21)
(2) Folículos vitelinos más pequeños, en dos grupos .......................................................................................... Gonocercella
b) Glándulas vitelinas anteriores al acetábulo ................................................................................................... Fellodistomidae
(1) Testes intercecales .................................................................................................................................. Antorchis (Fig.4-13)
(2) Testes extracecales ................................................................................................................................... Bacciger (Fig. 4-98)
b. Ovario entre los testes.
1) Boca rodeada por papilas ................................................... Cryptogonimidae .............................Palaeocryptogonimus (Fig. 4-23)
130 A
BLA
 V
ol. 1 – Thatcher: Parásitos de Peces A
m
azónicos
2) Boca simple ........................................................................... Callodistomidae ......................................... Prosthenhystera (Fig. 4-7)
c. Ovario anterior a los testes.
1) Ventosa oral provista con espinas.
a) Glándulas vitelinas laterales al acetábulo ................ Heterophyidae ....................................................Parspina (Fig. 4-20)
b) Glándulas vitelinas posteriores al acetábulo ........... Acanthostomidae ..................................... Acanthostomum (Fig. 4-1)
2) Ventosa oral provista de collar espinoso ........................ Echinostomatidae ................................... Caballerotrema (Fig. 4-16)
3) Ventosa oral con extensiones membranosas ................. Allocreadiidae.
a) Ventosa oral con lóbulos .................................................................................................................. Crepidostomum (Fig. 4-10)
b) Ventosa oral con estructura parecida a gorra .................................................................................... Creptotrema (Fig. 4-11)
4) Ventosa oral simple.
a) Glándulas vitelinas consisten de dos masas compactas en región central ................................................ Gorgoderidae
(1) Masas vitelinas alongadas ................................................................................................................ Dendrorchis (Fig. 4-19)
(2) Masas vitellinas menores que los testes .................................................................................Amazonadistoma (Fig. 4-2)
(3) Masas vitelinas mayores que los testes ................................................................................. Phyllodistomoides (Fig. 4-25)
b) Glándulas vitelinas consisten de folículos en áreas limitadas posteriores al acetábulo.
(1) Testes cerca de la extremidad posterior. Ventosas desiguales.
(a) Prefaringe larga ................................................ Opisthorchiidae .............................................. Witenbergia (Fig. 4-8)
(b) Prefaringe corta ................................................ Allocreadiidae ............................................ Procaudotestis (Fig. 4-14)
(2) Testes cerca de la extremidad posterior; acetábulo mucho más pequeño que la ventosa oral ................................
................................................................................... Opisthorchiidae ................................................ Cladocystis (Fig. 4-9)
(3) Testes en la mitad posterior del cuerpo; acetábulo más largo que la ventosa oral; faringe grande, con extensiones
anteriores similares a dedos .................................. Fellodistomidae ........................................... Kalipharynx (Fig. 4-15)
c) Glándulas vitelinas consisten de folículos grandes y limitados a dos áreas laterales al acetábulo ........................................................................................................................... Allocreadiidae .........................................Magnivitellinum (Fig. 4-17)
d) Glándulas vitelinas consisten de folículos pequeños y extensos, especialmente en la mitad posterior del cuerpo.
(1) Áreas laterales vitelinas unidas anterior y posteriormente al acetábulo ........................................................................
................................................................................... Allocreadiidae ................................................. Crassicutis (Fig. 4-18)
(2) Áreas laterales vitelinas no unidas anteriormente .... Lepocreadidae ................................................Eocreadium (Fig. 4-12)
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 131
VII. Checklist of Trematoda (Digenea) from Neotropical freshwater fishes
Measurements are given in millimeters except for the circumoral spines and eggs which
are in micrometers (µm). Abreviations used are: A = acetabulum; B = body size; CS =
cirrus sac; E = esophagus; EB = esophagus bulb; FB = forebody; G = gut; GS = genital
sac; HB = hindbody; HC = head collar; HS = hermaphroditic sac; Mir = miracidia; OS =
oral sucker; Ph = pharynx; Rhy = rhynchus.
Acanthostomidae POCHE, 1926
Body long and cylindrical. Oral sucker well developed; circumoral spines
normally present; pharynx present. Acetabulum small. Cirrus sac absent.
Ovary anterior to two testes. Excretory vesicle Y-shaped. Intestinal tract
of marine and freshwater fish and reptiles.
Acanthostostomum LOOSS, 1899
Oral sucker terminal, funnel-shaped; circumoral spines present; prephar-
ynx long; esophagus short; intestinal crura open through anal pores. Testes
near posterior extremity. Genital pore preacetabular. Intestinal tract of fish
and aquatic reptiles.
A. gnerii SZIDAT, 1954: Rhamdia quelen and R. rogersi: Costa Rica & Argentina.
(Fig. 4-1). B = 1.6-2.0; 21-23 circumoral spines; OS = 0.25 x 0.20; Ph =
0.12 x 0.10; Vitelline glands large, 7-9 per side; Egg = 29-37 x 14-16 µm.
Allocreadiidae (LOOSS, 1902) STOSSICH, 1903
Oral sucker subterminal, sometimes with projections. Acetabulum simple,
pre-equatorial. Prepharynx, pharynx and esophagus usually present; ceca
usually long. Cirrus sac present or absent. Testes tandem, postequatorial.
Ovary pretesticular. Genital pore median or submedian. Excretory vesicle
short. Intestine of fish, amphibia and aquatic reptiles.
Crassicutis MANTER, 1936
Body elongate, flattened; tegument thickened. Oral sucker large; esophagus
short; ceca long. Acetabulum smaller than oral sucker. Cirrus sac absent. Genital
pore median, just anterior to acetabulum. Ovary submedian. Seminal receptacle
present. Uterus with few large eggs, Intestine of freshwater and marine fish.
C. chuscoi (PEARSE, 1920) PETERS, 1957: Aequidens pulcher: South America. B =
0.56 x 0.29.
C. cichlasomae MANTER, 1936: Cichlasoma mayorum: México (Yucatan), Costa Rica
and Cuba (Fig. 4-18). B = 0.88-1.3 x 0.48-0.83; Egg = 110-114 x 64-66 µm.
C. opisthoseminis BRAVO-HOLLIS & ARROYO, 1961: Cichlasoma sp.: Costa Rica. B
= 3.3 x 1.6; Egg = 120 x 82 µm.
C. wallini (PEARSE, 1920) PETERS, 1957: Crenicichla geayi: Venezuela. B = 1.55 x
0.74; Egg = 118-130 x 66-71 µm.
Crepidostomum BRAUN, 1900.
Oral sucker with 6 lobes; prepharynx present; ceca long. Cirrus sac
elongate. Ovary submedian; seminal receptacle present. Intestinal tract of
freshwater fishes and reptiles.
132 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
C. macrorchis SZIDAT, 1954: Roeboides bonariensis: Argentina. (Fig. 4-10). B = 1.5
x 0.5; OS = 0.18 x 0.20; A = 0.15; Ph = 0.07 x 0.05; Egg = 55 x 29 µm.
C. platense SZIDAT, 1954: Pimelodus clarias and Iheringichthys labrosus: Argentina. B
= 0.8 x 0.2; OS = 0.12; A = 0.12; Egg = 75 x 39 µm.
Creptotrema TRAVASSOS, ARTIGAS & PEREIRA, 1928.
Oral sucker large, with two dorsal lobes. Pharynx present; esophagus short;
ceca long. Acetabulum similar in size to oral sucker; pre-equatorial. Cirrus
sac long. Genital pore medial, near bifurcation. Ovary between testes and
acetabulum. Vitelline follicles large; lateral, extending from pharynx to
posterior extremity. Eggs few, large. Excretory vesicle tubular. Intestine of
freshwater fish.
C. creptotrema TRAVASSOS, ARTIGAS & PEREIRA, 1928: Leporinus elongatus: Brazil.
(Fig. 4-11). B = 0.47 x 0.54 x 0.24-0.28; OS = 0.11-0.13; A = 0.16; Ph =
0.04; Egg = 72-78 x 44-50 µm.
C. díspar TEXEIRA DE FREITAS, 1941: Triportheus paranensis: Brazil. B = 1.8 x
0.67; OS = 0.19-0.23; A = 0.26 x 0.27; Ph = 0.06; Egg = 80 x 46 µm.
Magnivitellinum KLOSS, 1966.
Oral sucker small; esophagus and ceca short. Acetabulum subequal to oral
sucker. Testes diagonal; in middle third of body. Cirrus sac small, curved.
Genital pore median, preacetabular. Ovary between testes and acetabulum.
Vitelline follicles large; extending length of ceca. Intestine of freshwater fish.
M.simplex KLOSS, 1966: Astyanax bimaculatus: Brazil. (Fig. 4-17). B = 2.7-3.5 x
0.74-1.1; OS = 0.20-0.27; A = 0.23-0.30; Ph = 0.086-0.11; Egg = 36-47 x
21-23 µm.
Procaudotestis SZIDAT, 1954
Body tapering posteriorly. Oral sucker larger than acetabulum. Genital
pore median, preacetabular. Cirrus absent; seminal vesicle large. Repro-
ductive organs in posterior half of body; ovary pretesticular; vitellaria
follicular, lateral. Excretory vesicle tubular. Intestine of freshwater fish.
P. uruguayensis SZIDAT, 1954: Loricaria vetula: Uruguay (Fig. 4-14). B = 2.2 x 0.65; OS
= 0.25 x 0.30; A = 0.22 x 0.25; Ph = 0.11 x 0.10; Egg = 80 x 92 x 40-44 µm.
Angiodictyidae LOOSS, 1902.
Oral sucker with or without lumenal diverticula; esophagus and esophageal
bulb present; ceca long. Cirrus sac usually absent. Genital pore median,
near anterior extremity. Ovary post-testicular. Lymphatic ( = circulatory)
system present in association with ceca. Excretory system reticulate. Eggs
large. Intestine of fish and turtles.
Curumai TRAVASSOS, 1961
Body flattened; without posterior projections. Oral sucker small; pharynx
absent; esophagus short; ceca long. Acetabulum absent. Cirrus sac small,
near bifurcation. Testes large, irregular, diagonal; pre-equatorial. Genital
pore anterior to bifurcation. Ovary spherical, post-testicular. Vitelline
follicles forming “V” from cecal ends to posterior testis. Excretory pore
subterminal. Intestine of fish.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 133
C. curumai TRAVASSOS, 1961: Myleus sp.: Brazil (Fig. 4-44). B = 6.5-8.0 x 1.0-2.0;
OS = 0.15-0.19 x 0.12-0.16; E = 0.43-0.78; Egg = 100-104 x 64-68 µm.
Denticauda FUKUI, 1929
Body with 4 projections and median notch posteriorly. Oral sucker simple;
esophageal bulb absent; ceca medium long. Testes tandem. Cirrus sac
absent. Genital sucker present; pore postbifurcal. Ovary median, post-
testicular. Excretory pore in median notch. Intestine of fish.
D. quadrangulata (DADAY, 1907): Colossoma bidens: Brazil. (Fig. 4-45). B = 1.7 x
0.65; OS = 0.13-0.14; Egg = 60 x 50 µm.
Pseudoparabaris YAMAGUTI, 1958
Body with posterior median notch. Oral sucker simple, terminal; esoph-
ageal bulb present; ceca medium long. Testes tandem, lobate. Seminal
vesicle long; cirrus sac absent. Genital pore at level of bifurcation. Ovary
median; vitelline follicles forming “V” with apex near ovary. Intestine of
freshwater fish.
P. parabaris (TRAVASSOS, 1922): Colossoma bidens: Brazil. (Fig. 4-46). B = 10.5 x
4.0; OS = 0.20; Ph = 0.29 x 0.27; Egg = 134 x 78µm.
Bucephalidae POCHE, 1907
Anterior attachment organ a rhynchus. Oral sucker and acetabulum
absent. Pharynx and esophagus present; mouth ventral; gut saccular or
tubular. Cirrus sac near posterior extremity; genital pore terminal or
subterminal. Vitelline follicles usually anterior. Position of testes and ovary
variable. Intestine of fish and amphibians.
BellumcorpusKOHN, 1962
Body elongate; rhynchus oval, without projections. Pharynx small, in
middle of body; gut large, directed posteriorly. Testes entire or indented,
diagonal, post-equatorial. Cirrus sac small; genital pore terminal. Ovary
opposite posterior testis; vitelline follicles in 4 – 5 lateral groups. Excretory
vesicle long, tubular. Stomach of freshwater fish.
B. major KOHN, 1962: Salminus hilarii: Brazil. (Fig. 4-4). B = 3.54-7.36 x 1.08-
2.25; Rhy = 0.42-0.63 x 0.18-0.28; Ph = 0.19-0.31 x 0.18-0.28; G = 1.37-
2.74 x 0.42-1.08; CS = 0.58-1.66 x 0.22 0.33; Egg = 22-26 x 18 µm.
Glandulorhynchus THATCHER, 1999
Body stout, flattened, unspined; rhynchus sucker-like, provided with
numerous glands. Pharynx small, near equator or posterior thereto; gut
saccular, mostly posterior to pharynx. Testes two, spherical, diagonal,
posterior to pharynx; cirrus sac small, at posterior extremity; genital pore
subterminal. Ovary spherical, anterior to pharynx; vitellaria in grape-like
clusters extending anterolaterally in anterior half of body; uterus tubular
forming massive uterine reservoir on side of body; eggs small, numerous.
Intestinal parasites of freshwater fishes. Type species: Glandulorhynchus
turgidus THATCHER, 1999
G. turgidus THATCHER, 1999: Hydrolycus sp.: Rondonia State, Brazil. (Figs. 4-91
& 4-92). B = 5.0-7.3 x 2.5-3.5; Rhy = 0.56-0.81 x 0.54-0.81; Ph = 0.21-0.31
134 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
x 0.25- 0.35; G = 0.60-1.9 x 0.46-0.62; CS = 1.2-1.5 x 0.27-0.42; Egg = 18-
20 x 9-11 µm.
Pararhipidocotyle KOHN, 1970
Body elongate, spinous. Rhynchus with cap; opening subterminal. Mouth
in middle of body; gut directed posteriorly. Testes parallel or diagonal, in
middle third of body. Cirrus sac elongate; genital pore ventral. Ovary post-
testicular. Vitelline follicles prececal. Excretory pore terminal. Intestine of
freshwater fish.
P. jeffersoni KOHN, 1970: Salminus maxillosus: Brazil. B = 0.90-1.04 x 0.22-0.29;
Rhy = 0.11-0.17 x 0.11-0.16; Ph = 0.054-0.063 x 0.57-0.060; E = 0.045-
0.075; G = 0.13-0.14 x 0.078-0.087; CS = 0.27-0.32 x 0.06-0.07; Egg = 30-
40 x 15-21 µm.
Paurorhynchus DICKERMAN, 1954
Body subcylindrical. Rhynchus small, funnel-shaped. Mouth in anterior
third; gut long, directed posteriorly. Testes large, lobate, diagonal, post-
equatorial. Cirrus sac small; genital atrium small; pore ventral. Ovary
lobate; opposite anterior testis. Vitellaria laterial, acinous. Excretory vesicle
long. Gall bladder of freshwater fish.
P. schubarti KOHN, 1963: Salminus maxillosus: Brazil. (Fig. 4-5). B = 7.73 x 2.8;
Rhy = 0.50 x 0.29; Ph = 0.29-0.32; G = 2.13-0.67; CS = 2.4-0.33; Egg =
not found.
Prosorhynchus ODHNER, 1905
Body rounded to elongate; spinous. Rhynchus plug or funnel-shaped,
without projections. Mouth in middle third; gut short. Testes tandem or
diagonal, in middle third or more posterior. Genital pore ventral or
terminal. Intestine of freshwater and marine fish.
P. costai TRAVASSOS, ARTIGAS & PEREIRA, 1928: Acestrorhamphus sp., Astyanax
fasciatus and Salminus hilarii: Brazil (Fig. 4-6). B = 1.0 x 0.2; Rhy = 0.13 x
0.12; Ph = 0.046; G = 0.15; Egg = 42-46 x 15 µm.
P. piranhus THATCHER, 1999: Serrasalmus rhombeus: Rondonia State, Brazil. (Fig.
4-90). B = 0.78-1.1 x 0.42-0.75; Rhy = 66-119 x 88-132 µm; Ph = 66-83 x
66-83 µm; G = 88-198 x 73-110 µm; CS = 0.18-0.49 x 0.07-0.11; Egg =
44-55 x 22-31 µm.
Callodistomidae POCHE, 1926
Body rounded or elongate. Oral sucker, pharynx and acetabulum present.
Ceca of variable length. Cirrus sac and genital pore preacetabular. Two
testes and ovary present; of variable position. Vitellaria lateral. Uterus
extensive; eggs small, numerous. Intestine and other organs of fish.
Prosthenhystera TRAVASSOS, 1920
Body elliptical to oval. Oral sucker and pharynx small; esophagus short;
ceca long. Acetabulum small, pre-equatorial. Testes parallel; in middle
third. Cirrus sac elliptical, postbifurcal. Genital pore just postbifurcal.
Ovary between acetabulum and left testis. Vitellaria in lateral groups. Gall
bladder of freshwater fish.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 135
P. obesa (DIESING, 1850) Salminus, Leporinus, Boulengerella, Acestrorhamphus,
Galeocharax, Pseudopimelodus, Pimelodus and Astyanax: Mexico, Colombia &
Brazil. (Fig. 4-7). B = 14 x 8; OS = 1.0-1.2; A = 0.95-1.3; Ph = 0.34; E =
1.3; Egg = 63-70 x 35-49 µm.
Cryptogonimidae CIUREA, 1933
Body small, oval or elongate. Oral sucker sometimes provided with
circumoral spines; pharynx present; esophagus short; ceca variable. Ace-
tabulum small, embedded. Testes single or multiple; post-equatorial.
Cirrus sac frequently absent. Ovary usually lobate. Vitellaria variable.
Excretory vesicle V or Y-shaped. Intestine of freshwater and marine fish
and aquatic reptiles.
Iheringtrema TRAVASSOS, 1948
Body small, scaled. Oral sucker large; pharynx present; esophagus short:
ceca thin, medium long. Acetabulum small, within genital atrium; in anterior
quarter. Testes 9 (4 on one side and 5 on the other); in posterior half.
Seminal vesicle long, sigmoid, postacetabular; cirrus sac absent. Genital pore
median; just preacetabular. Ovary of 3 notched lobes; pretesticular. Seminal
receptacle present. Vitellaria extensive. Intestine of fish.
I. iheringi TRAVASSOS, 1948: Pseudopimelodus roosevelti: Brazil. (Fig. 4-22). B = 3.5 x 4.0
x 1.0-1.2; OS = 0,38-0.39; A = 0.17-0.18; Ph = 0.15-0.18; Egg = 38 x 22 µm.
Palaeocryptogonimus SZIDAT, 1954
Body tapered posteriorly; scaled anteriorly. Oral sucker terminal, retractile,
without spines; prepharynx present; pharynx large; esophagus short; ceca
medium long. Acetabulum near anterior extremity; covered by circular
pad. Testes nearly parallel; in midregion. Seminal vesicle tripartite; postac-
etabular. Cirrus sac absent. Genital pore between acetabulum and circular
pad. Ovary median, pretesticular. Vitellaria of large follicles; lateral in
acetabular region. Seminal receptacle present. Excretory vesicle. Y-shaped,
pore terminal. Stomach and intestine of fish.
P. claviformis SZIDAT, 1954; Rhinodoras dorbignyi: Argentina. (Fig. 4-23). B = 1.25
x 0.45; OS = 0.12; Ph = 0.09 x 0.06; Egg = not found.
Didymozoidae POCHE, 1907
Hemaphroditic or partly gonochoristic. Usually encysted in pairs in tissue.
Body form variable; frequently thread-like, or with slender forebody and
expanded hindbody. Pharynx and acetabulum present or absent. Repro-
ductive organs usually elongate, tubular, winding. Uterus extensive; eggs
small, numerous. Excretory vesicle long, pore terminal. Tissues of marine,
and rarely freshwater fish.
Brasicystis THATCHER, 1979
Hermaphroditic; encysted in pairs in subcutaneous tissue. Body divided
into slender forebody and expanded hindbody; hindbody laterally flat-
tened, flexed ventrally in anterior part and curved ventro-laterally in
posterior part. Oral sucker, pharynx and esophagus present; ceca long.
Acetabulum absent. Testis single, slender, extends to posterior extremity.
136 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
Seminal vesicle present; cirrus sac absent. Genital pore lateral to oral
sucker. Ovary long, tubular; shorter than testis. Vitelline gland single,
tubular, extends to posterior extremity on dorsal side. Uterus extensive,
eggs small. Subcutaneous cysts in freshwater fish.
B. bennetti THATCHER, 1979: Plagioscion squamosissimus: Brazil (Figs. 4-3 & 4-47).
FB = 1.2-2.8 x 0.10-0.22; HB = 9.5-16 x 1.0-1.2; OS = 0.04-0.06 x 0.02-
0.03; Ph = 0.03-0.05; Egg = 14-16 x 8-9 µm.
Echinostomatidae POCHE, 1926
Body elongate, normally with head collar bearing 1-2 rows of spines;
tegument spined or scaled. Oral sucker, prepharynx and esophagus
present; ceca long. Acetabulum large; in anterior or middle third. Testes
tandem or diagonal. Genital pore median; preacetabular. Ovary pretesticu-
lar; seminal receptacle absent.Vitelline follicles lateral and posterior. Eggs
large. Excretory vesicle Y-shaped. Intestine of reptiles, birds, mammals
and rarely fish.
Caballerotrema PRUDHOE, 1960, THATCHER, 1980
Body long, cylindrical. Head collar wide and flattened, with single row of
spines; ventral lobe (on each side) with 4 spines in 2 pairs. Oral sucker
small, with membranous extension antero-dorsally and laterally; esophagus
long. Acetabulum large, anterior. Cirrus sac large; extending posterior to
acetabulum; external seminal vesicle present. Gonads in midbody. Vitelline
follicles dorsolateral from preovarian region to cecal ends. Intestine of
freshwater fish.
C. arapaimense THATCHER, 1980: Arapaima gigas: Brazil (Amazonia). (Fig. 4-16).
B = 3,8-8.3 x 0.62-0.77; HC = 0.83-1.02; large spines = 84-200 x 27-48
µm; small spines = 67-139 x 18-36 µm ; OS = 0.14-0.30; E = 0.31-0.36; Ph
= 0.26-0.36 x 0.11-0.27; A = 0.33-0.87 x 0.29-0.56; CS = 0.47-0.82 x 0.22-
0.42; Egg = 72-83 x 28-58 µm.
C. aruanense THATCHER, 1980: Osteoglossum bicirrhosum: Brazil (Amazônia). B =
5,8-9.1 x 0.39-0.62; HC = 0.63-0.88; large spines = 72-98 x 24-32 µm;
small spines = 47-65 x 28 µm ; OS = 0.11-0.16; E = 0.30-0.42; Ph = 0.18-
0.22 x 0.12-0.16; A = 0.36-0.45 x 0.31-0.42; CS = 0.74-1.2 x 0.21-0.25; Egg
= 70-97 x 43-60 µm.
C. brasiliense PRUDHOE, 1960, THATCHER, 1980: Arapaima gigas: Brazil (Amazo-
nia). B = 4.6-11.3 x 0.51-0.74; HC = 0.60-1.0; large spines = 67-90 x 26-47
µm; small spines = 34-60 x 14-35 µm ; OS = 0.11-0.19; E = 0.25-0.45; Ph
= 0.19-0.30 x 0.09-0.14; A = 0.29-0.41 x 0.25-0.40; CS = 0.38-0.64 x 0.26-
0.35; Egg = 80-84 x 48-56 µm.
Fellodistomidae NICOLL, 1913
Body shape variable. Oral sucker, pharynx and esophagus present; ceca of
variable length, sometimes forming ring. Acetabulum medium to large.
Testis or testes in posterior half. Cirrus and genital pore usually preacetab-
ular. Ovary variable, usually pretesticular. Vitellaria lateral, variable in
form. Intestine of marine and freshwater fish.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 137
Antorchis LINTON, 1911
Body fusiform spinous. Oral sucker large, cup-shaped with notched
ventral lip; pharynx small; esophagus long; ceca short. Acetabulum in
middle third. Testes parallel, anterolateral to acetabulum. Cirrus sac and
genital pore preacetabular. Ovary dorsal or posterior to acetabulum.
Vitelline follicles pretesticular, extracecal. Uterus occupying hindbody.
Excretory vesicle V or Y-shaped. Intestine of freshwater and marine fish.
A. lintoni TRAVASSOS, ARTIGAS & PEREIRA, 1928: Astyanax fasciatus: Brazil. (Fig.
4-13). B = 0.9 x 0.4; OS = 0.15; A = 0.15; Ph = 0.06; Egg = 30 x 15 µm.
Bacciger NICOLL, 1914
Body rounded to oval, spinous. Oral sucker ventro-terminal; pharynx well
developed; esophagus short; ceca reaching to or slightly beyond testes.
Acetabulum equatorial or pre-equatorial. Testes spherical or ovoid, sym-
metrical or subsymmetrical at postacetabular level. Cirrus sac pyriform to
oval or elliptical, preacetabular, enclosing saccular seminal vesicle, prostat-
ic complex and ejaculatory duct. Genital pore median, postbifurcal. Ovary
rounded or weakly lobate, inter or post-testicular; seminal receptacle and
Laurer’s canal present; vitelline follicles in symmetrical groups outside
ceca; uterine coil occupying most of hindbody; Eggs small, numerous.
Intestinal parasites of marine and freshwater teleosts.
B. pellonae THATCHER, 1992: Pellona castelnaeana: Guaporé River, Rondônia
State, Brazil. (Fig. 4-98). B = 0.60-0.74 x 0.35-0.49; A = 50-94 µm; OS =
72-88 x 82-105 µm; CS = 82-116 x 5-82 µm; Eggs = 28-44 x 19-28 µm.
Kalipharynx BOEGER & THATCHER, 1984
Body elongate, tapering posteriorly, tegument spinous. Oral sucker subter-
minal, large, but with weak musculature; pharynx large, strongly muscled,
with digitiform processes anteriorly; esophagus short; ceca long. Acetabu-
lum large, shallow; pre-equatorial. Testes diagonal, post-acetabular, posto-
varian. Cirrus sac long, thin. Genital pore ventro-lateral; between suckers.
Vitelline follicles lateral, postacetabular. Uterus in posterior half of body;
eggs small, numerous. Excretory pore terminal. Intestine of fish.
K. piramboae BOEGER & THATCHER, 1984: Lepidosiren paradoxa: Brazil. (Fig. 4-
15). B = 1.65-3.25 x 0.73-0.88; OS = 0.13-0.20 x 0.23-0.33; Ph = 0.18-0.25
x 0.25-0.30 (with 6 anterior digitiform processes); A = 0.53-0.83; CS =
0.49-0.94 x 0.06-0.10; Egg = 25-40 x 13-20 µm.
Gorgoderidae LOOSS, 1901
Body narrowed anteriorly, expanded posteriorly; tegument unspined. Oral
sucker present; pharynx often absent; ceca long, may be sinuous, some-
times forming ring. Acetabulum large, projecting. Testes two, or more,
postacetabular, parallel or diagonal. Cirrus sac absent. Genital pore
medium, between bifurcation and acetabulum. Ovary submedian, postace-
tabular. Vitellaria double, compact or lobed, postacetabular. Uterus exten-
sive in hindbody; eggs small. Excretory pore terminal. Instestine or urinary
bladder of fishes, amphibians and reptiles.
138 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
Amazonadistoma THATCHER, 1979
Body cylindrical and tapered anteriorly, rounded and flattened posteriorly;
tegument unspined but with muscular corrugations postero-laterally. Oral
sucker large; esophagus short; ceca long, with diverticula and microvilli;
bifurcation near posterior margin of oral sucker. Acetabulum large, pre-
equatorial. Testes parallel or diagonal, postequatorial. Seminal vesicle
small, sinuous. Genital pore and genital sucker between oral sucker and
acetabulum. Ovary submedian, pretesticular. Vitelline glands, two parallel
masses; pretesticular. Uterus extensive, sinuous; eggs small. Excretory
vesicle long, tubular; pore terminal. Intestine of freshwater fish.
A. negrensis THATCHER, 1979: Gymnorhamphichthys hypostomus: Brazil. (Fig. 4-2). B
= 5.3-6.3 x 2.2-2.6; OS = 0.66-0.76; A = 0.53-0.59; Egg = 30 x 23 µm.
Dendrorchis TRAVASSOS, 1926
Body pyriform, flattened. Oral sucker ventro-terminal; bifurcation nearer
oral sucker than acetabulum; ceca long. Acetabulum similar in size to oral
sucker. Testes diagonal, branched. Cirrus sac small, transverse. Genital
pore submedian, between bifurcation and acetabulum. Ovary submedian
at level of anterior testis; vitelline glands transversely oval, between
acetabulum and ovary. Uterus extensive. Excretory vesicle tubular, pore
terminal. Swimbladder of fish.
D. neivai TRAVASSOS, 1926; Brycon lundi: Brazil. (Fig. 4-19). B = 6-8 x 4-5; OS =
0.6-0.7; A = 0.67-0.9; E = 0.4-0.8; Egg = 35-53 x 30-38 µm.
Phyllodistomoides BROOKS, 1977.
Body pyriform, without spines. Oral sucker subterminal; prepharynx
absent; pharynx present; esophagus and ceca long. Acetabulum pre-
equatorial. Testes compact, intercecal, postacetabular. Ovary submedian,
pretesticular, postacetabular. Vitelline glands lateral to acetabulum. Uterus
extensive. Swimbladder of fish.
P. ducani BROOKS, 1977: Astyanax sp.: Colombia. (Fig. 4-25). B = 1.7 x 0.85; OS
= 0.28-0.34; Ph = 0.96 x 0.11; E = 0.96; A = 0.18 x 0.20; Egg = 46 x 29 µm.
Halipegidae POCHE, 1926
Body rounded or elongate, without ecsoma. Oral sucker subterminal;
pharynx small; esophagus short; ceca long, sometimes forming ring.
Acetabulum large. Testes parallel or diagonal, postacetabular. Seminal
vesicle tubular or saccular; hermaphroditic duct short, usually within sac or
genital cone; genital atrium near bifurcation. Ovary near posterior extrem-
ity; vitelline glands of two masses or several lobes, postovarian. Uterus
extensive; eggs sometimes filamented. Excretory branches united anterior-
ly. Stomach of marine and freshwater fish and amphibians.
Gonocercella MANTER, 1940
Body subcylindrical; tegument transversely annulated. Oral sucker subter-
minal, large with preoral lobe; esophagus short; ceca long. Acetabulum
larger than oral sucker, postequatorial.Testes diagonal, postacetabular;
seminal vesicle coiled, anterior to acetabulum; prostatic vesicle large;
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 139
hermaphroditic duct within genital cone which projects into conical
genital atrium; genital pore median, postbifurcal. Ovary post-testicular;
vitellaria of two compact or lobed masses, postovarian. Egg without
filaments. Stomach of freshwater fish.
G. magnifica SZIDAT, 1954: Hypostomus plecostomus and H. commersoni: Argentina. B =
5 x 2; OS = 0.45; A = 0.66-0.75; Ph = 0.20 x 0.22; Egg = 50-55 x 20-22 µm.
Halipegus LOOS, 1899
Body elongate, unspined. Oral sucker with preoral lobes; pharynx present;
esophagus short; ceca long. Acetabulum large. Testes nearly parallel, postac-
etabular. No cirrus sac and no hermaphroditic bursa; seminal vesicle
saccular. Genital pore postero-ventral to pharynx. Ovary near posterior
extremity; vitelline glands postovarian, of two compact lobes or two groups
of 4 – 5 lobes each. Uterus extensive; eggs with polar filaments. Excretory
branches uniting near anterior extremity. Digestive tract of frogs and fish.
H. dubius KLEIN, 1905: Salminus maxillosus and Cynopotamus humeralis: Brazil.
(Fig. 44-20). B = 3.3-4.0 x 1.1-1.5; OS = 0.36-0.49 x 0.46-0.53; A = 0.54-
0.66 x 0.61-0.66; Egg = 42-52 x 17-22 µm. (filaments = 138-221 µm).
H. genarchella (TRAVASSOS, ARTIGAS & PEREIRA, 1928) Astyanax, Acestrorhamphus,
Cynopotamus, Moenklausia and Roeboides: Brazil. B = 2.1- 4 x 0.78-1.6; OS =
0.36-0.52; A = 0.68-1.0; Ph = 0.13-0.18; Egg = 48-58 x 24 µm. (polar
filaments present).
H. parvus (TRAVASSOS, ARTIGAS & PEREIRA, 1928): Acestrorhamphus and Salminus:
Brazil. B = 2.1-2.6 x 0.52-0.53; OS = 0.42-0.65; A = 0.36-0.39; Ph = 0.1;
Egg = 85 x 57 µm.
H. tropicus (MANTER, 1936): Astyanax, Charax, Leporinus, Luciopimelodus, Loricaria
and Pimelodus: México, Brazil & Argentina. B = 2.27-4.2 x 0.45-0.7; OS = 0.29-
0.43; Ph = 0.12-0.16; A = 0.48-0.58 x 0.52-0.66; Egg = 44-52 x 23-29 µm.
Haploporidae NICOLL, 1914
Body small, rounded or conical; spinous. Oral sucker subterminal;
prepharynx present; esophagus long; ceca usually short or saccular.
Acetabulum in middle third of body. Testis postacetabular; seminal vesicle
internal and external to hermaphroditic sac. Genital pore median, preace-
tabular. Ovary small, median, anterior to testis; vitellaria of paired lobes or
bunches, lateral or posterior to ovary. Uterus extensive; eggs large,
miracidial eyespot frequently visible. Excretory vesicle variable, pore
terminal. Intestine of freshwater and marine fish.
Chalcinotrema TEXEIRA DE FREITAS, 1947
Body elongate, spinous. Oral sucker subterminal; prepharynx present;
esophagus long; ceca short to medium. Acetabulum similar in size to oral
sucker. Testis near posterior extremity; hermaphroditic sac and external
seminal vesicle present. Genital pore submedian, preacetabular. Ovary far
anterior to testis; seminal receptacle present; vitellaria of elongate lobes,
lateral, in posterior half of body. Uterus extensive; eggs numerous.
Excretory vesicle tubular. Intestine of freshwater fish.
140 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
C. lucieni BROOKS 1977: Leporinus muyscorum: Colombia. (Fig. 4-26). B = 4.44-
5.15 x 1.6-1.9; OS = 0.29-0.37 x 0.40-0.47; A = 0.44-0.55; Ph = 0.20-0.24
x 0.19-0.23; E = 0.66-0.88; Egg = 104-120 x 75-89 µm.
C. ruedasueltensis THATCHER, 1978: Astyanax fasciatus: Colombia. (Fig. 4-33). B =
1.4-1.5 x 0.46-0.47; OS = 0.15-0.16; Ph = 0.081-0.082; A = 0.14-0.15; HS
= 0.15-0.16 x 0.075-0.10; Egg = 90-102 x 50-60 µm.
C. salobrensis TEXEIRA DE FREITAS, 1947: Tryportheus paranensis: Brazil. B = 4.2 x
1.4; OS = 0.36; A = 0.35 x 0.32; Ph = 0.26; Egg = 96 x 66 µm.
Lecithobotrioides THATCHER & DOSSMAN, 1974
Body cylindrical, spinous. Acetabulum in anterior half of body. Oral
sucker subterminal; prepharynx short; pharynx smaller than sucker;
esophagus long; ceca medium long. Testis in posterior half of body;
hermaphroditic sac present; external seminal vesicle elongate, curved.
Genital pore preacetabular. Ovary spherical or ovoid, in middle third;
seminal receptacle absent; vitellaria variable, extensive, lateral. Uterus
posterior to genital pore; eggs few, large without miracidial eyespots.
Excretory vesicle saccular, pore terminal. Intestine of freshwater fish.
L. mediacanoensis THATCHER & DOSSMAN, 1974. Prochilodus reticulatus: Colombia.
(Fig. 4-31). B = 2.1-3.7 x 0.63-0.67; OS = 0.21-0.27; Ph = 0.13-0.18; A =
0.22-0.27; HS = 0.37-0.78 x 0.11-0.26; Egg = 74-100 x 45-52 µm.
L. elongatus THATCHER, 1999: Prochilodus nigricans: Guaporé River, Rondonia
State, Brazil. (Fig. 4-94). B = 3.0-3.9 x 0.83-1.0; OS = 0.17-0.22 x 0.19-
0.30; Ph = 0.16-0.17 x 0.17-0.24; A = 0.37-0.39 x 0.37-0.39; HS = 0.26-
0.59 x 0.19-0.30; Egg = 90-118 x 57-73 µm.
Megacoelium SZIDAT, 1954, THATCHER & VARELLA, 1981.
Body elongate, tapered posteriorly, compressed laterally. Tegument with
horizontal rows of spines to posterior extremity; spines usually present
inside both suckers. Oral sucker large, subterminal; prepharynx short;
pharynx large; esophagus short; ceca medium long, laterally compressed.
Acetabulum large, pre-equatorial. Testis elongate, sometimes sinuous,
postequatorial; hermaphroditic sac pyriform or oval, containing hermaph-
roditic cirrus; external seminal vesicle tubular; genital pore median or
submedian. Ovary spherical, median, anterodorsal to testis; uterus exten-
sive; uterine seminal receptacle sometimes present. Eggs numerous, with
short polar projection opposite operculum; with or without miracidial
eyespots. Excretory pore terminal. Stomach of freshwater fish.
M.plecostomi SZIDAT, 1954: Hypostomus plecostomus: Argentina B = 2.7 x 1.7; Egg
= 130-138 x 70 µm.
M.spinicavum THATCHER & VARELLA, 1981: Pterygoplichthys pardalis: Brazil
(Amazônia). (Fig. 4-24 A-B). B = 3.5-4.9 x 1.2-1.7; OS = 0.52-0.58 x 0.48-
0.55; Ph = 0.27-0.37; A = 0.64-0.75 x 0.55-0.79; HS = 0.37-0.64 x 0.2-
0.30; Egg = 95-110 x 50-60 µm.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 141
M.spinispecum THATCHER & VARELLA, 1981: Pterygoplichthys sp.: Brazil. B = 5.4-
7.7 x 2.7-3.0; OS = 0.88-0.95 x 0.81-0.88; Ph = 0.45-0.47; A = 1.2; HS =
0.64-1.0 x 0.33-0.45; Egg = 83-100 x 43-57 µm.
Paralecithobotrys TEXEIRA DE FREITAS, 1947
Body elongate, unspined. Oral sucker subterminal; prepharynx absent;
pharynx present; esophagus and ceca long. Acetabulum slightly larger than
oral sucker, pre-equatorial. Testis in midbody; hermaphroditic sac U-
shaped, preacetabular, genital pore submedian. Ovary immediately pretes-
ticular; vitellaria of few scattered follicles in midbody; uterus extensive;
eggs with miracidial eyespots. Excretory vesicle Y-shaped, pore terminal.
Intestine of freshwater fish.
P. brasiliensis TEXEIRA DE FREITAS, 1947. Lahilliela kneri and Leporinus elongatus.:
Brazil. (Fig. 4-36). B = 2.1-4.7 x 0.74-1.4; OS = 0.25-0.41 x 0.28-0.41; Ph =
0.14-0.22 x 0.10-0.16; A = 0.33-0.55 x 0.36-0.53; Egg = 87-113 x 52-70 µm.
Rondotrema THATCHER, 1999
Body small, stout, tapering towards both extremities, not flattened; tegument
not spinous. Oral sucker large, subterminal; prepharynx short; pharynx large,
spherical; esophagus long; ceca medium long, slender. Acetabulum large,
pre-equaorial. Testis small, single, spherical or irregular, postequatorial;
hermaphroditic sac large, pyriform, containing internal seminal vesicle,
cirrus and distal part of uterus; genital pore medial, immediately preacetab-
ular. Ovary ovoid, pretesticular, lateral to midline; vitellaria of two grape-like
clusters, one on each side, lateral to testis but intercecal; uterus with
descending and ascending loops; eggs large, containing miracidia with eye-
spots. Excretory vesicle tubular, pore terminal. Intestinal parasites of
freshwater fishes. Type species: Rondotrema microvitellarum, THATCHER,1999.
R. microvitellarum THATCHER, 1999; Hemiodus microlepis: Guaporé River, Ron-
donia State, Brazil. (Fig. 4-93). B = 0.63-1.2 x 0.31-0.59; OS = 0.11-0.16 x
0.13-0.21; Ph = 55-79 x 66-92 µm; Ceca = 22-66 µm in diameter; A =
0.11-0.17 x 0.14-0.22; Egg = 42-66 x 22-26 µm.
Saccocoelioides SZIDAT, 1954, THATCHER, 1978
Body fusiform or elongate, tegument spined or not. Oral sucker subtermi-
nal; prepharynx short; pharynx similar in size to oral sucker; esophagus long;
ceca medium or long. Acetabulum nearly equatorial, similar to oral sucker in
size. Testis spherical or oval, postequatorial; hermaphroditic sac larger than
pharynx; internal and external seminal vesicles present; genital pore median
or submedian, between acetabulum and pharynx. Ovary spherical, immedi-
ately pretesticular; vitelline follicles dorso-lateral, usually extending from
acetabulum to posterior margin of testis; uterine coils on both side of body,
from genital pore to testis; eggs with or without miracidial eyespots.
Excretory vesicle Y-shaped, pore terminal. Intestine of freshwater fish.
S. leporinodus THATCHER, 1978: Leporinodus vittatus: Colombia. (Fig. 4-34). B =
8.0-8.6 x 0.37-0.46; OS = 0.093-0.13; Ph = 0.09-0.13; A = 0.10-0.12; HS =
0.093-0.11 x 0.11-0.14; Egg = 62-80 x 29-34 µm.
142 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
S. magniovatus SZIDAT, 1954: Leporinus obtusidens: Argentina. B = 0.7 x 0.36; OS
= 0.11; Ph = 0.09; A = 0.12; Egg = 95-114 x 41-60 µm.
S. magnorchis THATCHER, 1978: Saccodon caucae: Colombia. B = 0.54-0.96 x 0.24-
0.51; OS = 0.075-0.10; Ph = 0.053-0.12; A = 0.094-0.11; HS = 0.067-0.10
x 0.11-0.19; Egg = 68-72 x 26-30 µm.
S. nanii SZIDAT, 1954: Prochilodus lineatus: Argentina. B = 0.72 x 0.24 – 0.30; OS
= 0.1; Ph = 0.055; A = 0.1; Egg = 85 x 38 µm.
S. octavus SZIDAT, 1970: Astyanax fasciatus: Argentina. B = 1.2 x 0.32; OS =
0.11; Ph = 0.08; A = 0.08; Egg = 110-150 x 60 µm.
S. quintus SZIDAT, 1954: Loricaria anus: Argentina. B = 1.12-1.13 x 0.49-0.50;
OS = 0.09; Ph = 0.06; A = 0.13; Egg = not given.
S. rotundus THATCHER & JÉGU, 1996: Mylesinus paraschomburgkii: Trombetas
River, Pará State, Brazil. (Fig. 4-58). B = 0.53-0.90 x 0.34-0.47; A = 0.12-
0.19 x 0.13-0.19; OS = 0.10-0.16 x 0.13-0.18; Ph = 53-115 x 80-103 µm.
HB = 0.14-0.18 x 0.078-0.10; Eggs = 71-109 x 32-42 µm.
S. saccodontis THATCHER, 1978: Saccodon caucae: Colombia. (Fig. 4-35). B = 0.74-
1.2 x 0.31-0.38; OS = 0.80-0.10; Ph = 0.082-0.11; A = 0.11-0.13; HS =
0.082-0.11 x 0.11-0.15; Egg = 64-75 x 29-32 µm.
S. szidati TRAVASSOS, TEXEIRA DE FREITAS & KOHN, 1969: Schizodon fasciatus: Brazil.
B = 1.5 x 0.7; OS = 0.16; Ph = 0.14; A = 0.16; Egg = 110-118 x 48-53 µm.
Unicoelium THATCHER & DOSSMAN, 1975
Body fusiform, spined. Oral sucker subterminal, prepharynx short; phar-
ynx smaller than suckers; ceca united to form bilobed sac, equatorial.
Acetabulum in midbody. Testis large, oval, in posterior third of body;
hermaphroditic sac preacetabular; external seminal vesicle pyriform; geni-
tal pore submedian, posterior to pharynx. Ovary small, spherical, just pre-
testicular; uterine seminal receptacle prominent, looped laterally from
ovary to near pharynx; uterus looped laterally on both sides, from pharynx
to testis; eggs large, with miracidial eyespots visible in distal portion of
uterus. Excretory vesicle Y-shaped. Intestine of freshwater fish.
U. prochilodorum THATCHER & DOSSMAN, 1975: Prochilodus reticulatus: Colombia
(Fig. 4-43). B = 0.96-1.62 x 0.37-0.66; OS = 0.14-0.19; Ph = 0.10-0.15; A =
0.15-0.24; HS = 0.13-0.22 x 0.052-0.15; Egg = 73-74 x 29 x 37 µm.
Heterophyidae ODHNER, 1914
Body small, with scale-like spines. Oral sucker and pharynx present; ceca
of variable length. Acetabulum usually present, median or submedian,
often enclosed in genital atrium. Testes single or double, variable in form
and location; cirrus sac absent; seminal vesicle well developed; genital pore
median or submedian, postbifurcal. Ovary usually pretesticular, seminal
receptacle normally present; vitellaria lateral, uterus extensive, eggs small.
Excretory pore terminal. Intestinal tract of vertebrates.
Parspina PEARSE, 1920
Body small, rounded, spined. Oral sucker terminal, with single circle of
spines, prepharynx and pharynx present, esophagus short; ceca long.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 143
Acetabulum smaller than oral sucker, pre-equatorial. Testes nearly parallel,
postequatorial; genital sac encloses large seminal vesicle and short ejacula-
tory duct; latter unites with distal end of uterus forming short hermaphro-
ditic duct which opens on anterior margin of acetabulum. Ovary spherical,
antero-ventral to testes; seminal receptacle present; vitellaria acinous,
extend along ceca from pharynx to ovary; uterus extensive; eggs small.
Excretory vesicle Y-shaped, pore terminal. Intestine of freshwater fish.
P. argentinensis SZIDAT, 1954: Pimelodus clarias: Argentina (Fig. 4-21). B = 0.86-
0.94 x 0.42; OS = 0.18 x 0.15 (with circle of 26 spines); Ph = 0.08 x 0.06;
Egg = 31 x 30 µm.
Lepocreadiidae NICOLL, 1935
Body variable, often oculate. Oral sucker occasionally provided with lobes;
prepharynx usually present; pharynx and esophagus present; ceca long.
Acetabulum pre-equatorial. Testes postequatorial; cirrus sac present;
genital pore variable in position. Ovary median or submedian, pretesticu-
lar; seminal receptacle present; vitellaria extensive. Excretory pore termi-
nal. Digestive tract of marine and freshwater fish.
Eocreadium SZIDAT, 1954
Body spatulate, with rounded ends; unspined. Oral sucker subterminal;
prepharynx and esophagus short; ceca long. Acetabulum smaller than oral
sucker, pre-equatorial. Testes parallel, in middle third; cirrus sac slender,
dorsal to acetabulum; external seminal vesicle present; genital pore just
anterior to acetabulum. Ovary trilobed, submedian, pretesticular; vitelline
follicles small, extensive; eggs large, few. Excretory vesicle tubular, pore
terminal. Stomach of freshwater fish.
E. intermedium SZIDAT, 1954: Hypostomus plecostomus: Argentina. (Fig. 4-12). B =
2.8-3.0 x 1.0; OS = 0.25-0.30; Ph = 0.15-0.18; A= 0.20-0.22; Egg = 110-
120 x 60-68 µm.
Monorchiidae ODHNER, 1911.
Body small, spinous. Oral sucker and acetabulum usually small. Pharynx
present; ceca usually long. Testes usually single, occasionally double
frequently located in hindbody. Cirrus sac well developed; metraterm well
developed, spinous. Parasites of marine and sometimes freshwater fishes
Genolopa LINTON, 1910
Body fusiform, spinous. Oral sucker funnel-shaped; pharynx well devel-
oped; esophagus short; ceca not reaching posterior extremity. Acetabulum
pre-equatorial. Testis single, postacetabular. Cirrus sac large, extending
posterior to acetabulum; genital atrium spined, opening between intestinal
bifurcation and acetabulum. Ovary compact or lobed, pretesticular;
vitellaria forming lateral bunches; uterus filling hindbody; metraterm
spined distally. Excretory vesicle small, with terminal pore. Parasites of
marine and freshwater teleosts.
G. magnacirrus THATCHER, 1996: Boulengerella lucia: Jamarí River, Rondonia
State, Brazil. (Figs. 4-70 & 4-72). B = 0.57-1.4 x 0.17-0.36; OS = 0.07-0.12
144 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
x 0.07-0.14; Ph = 0.06-0.09 x 0.05-0.09; A = 0.78-0.12 in diameter; CS =
0.30-0.56 x 0.05-0.15; Eggs = 16-23 x 8-10 µm.
Paraproctotrema YAMAGUTI, 1934
Body spindle-shaped, spinous. Oral sucker subterminal; pharynx large;
esophagus longer than pharynx; ceca not reaching posterior extremity.
Acetabulum larger than oral sucker, pre-equatorial. Testis single, postequa-
torial. Cirrus sac extending posterior to acetabulum. Genital atrium
spined, opening anterior to acetabulum. Ovary lobed, postero-lateral to
acetabulum. Vitellaria of large compact follicles on each side in ovariotes-
ticularzone. Metraterm spinous. Eggs numerous, small. Parasitic in marine
and freshwater teleosts.
P. delicata THATCHER, 1996: Boulengerella lucia: Jamarí River, Rondonia State,
Brazil. (Figs. 4-68 & 4-71). B = 0.79-1.7 x 0.21-0.28; OS = 0.07-0.10; Ph =
0.046-0.074 x 0.04-0.069; A = 0.09-0.11 in diameter; CS = 0.18-0.30 x
0.041-0.078; Eggs numerous, small, 16-18 x 7-9 µm.
Sphericomonorchis THATCHER, 1996
Body small, ovoid, slightly flattened, spinous. Oral sucker subterminal;
prepharynx short; pharynx spherical; esophagus short; ceca long, stout.
Acetabulum pre-equatorial. Testis single, large, spherical, near posterior
extremity; cirrus sac large, elongate, containing spinous cirrus, seminal
vesicle and prostatic cells; genital pore medial, between intestinal bifurca-
tion and acetabulum. Ovary subspherical or irregularly lobate, immediately
pretesticular, lateral to midline; vitellaria of two bunches of large follicles,
lateral to acetabulum; metraterm elongate, saccular, spinous; uterus occu-
pying space between testis and acetabulum. Eggs small, numerous.
Excretory vesicle tubular, pore terminal. Intestinal parasites of freshwater
fish. Type species: Sphericomonorchis spinulosus THATCHER, 1996.
S. spinulosus THATCHER, 1996: Crenicichla johanna: Jamari River, Rondonia State,
Brazil. (Fig. 4-69). B = 0.66-1.2 x 0.17-0.46; OS = 0.08-0.11 x 0.093-0.13;
Ph = 0.033-0.066 x 0.038-0.066; A = 0.11-0.15 x 0.11-0.14; CS = 0.19-0.22
x 0.038-0.066; Eggs = 16-24 x 10-14 µm.
Opisthorchiidae BRAUN, 1901
Body small to elongate. Oral sucker small; pharynx present; ceca medium
to long. Acetabulum small, embedded, pre-equatorial. Testes variable in
form and position; cirrus sac absent; seminal vesicle tubular, genital pore
just preacetabular. Ovary submedian, usually pretesticular; seminal recep-
tacle present; vitellaria variable; uterus extensive. Excretory vesicle Y-
shaped. Gall bladder, bile ducts or intestine of vertebrates.
Cladocystis POCHE, 1926
Body flattened, elliptical. Oral sucker small; prepharynx and pharynx
present; esophagus short; ceca medium to long. Acetabulum small, pre-
equatorial. Testes large, indented, side by side near posterior extremity;
seminal vesicle tubular, sinuous, cirrus sac absent; genital pore preacetabu-
lar. Ovary median, trilobed; seminal receptacle postovarian; vitellaria
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 145
lateral; from seminal vesicle to testes; uterus extensive. Excretory branches
extend to oral sucker. Intestine of birds, rarely fishes.
C. intestinalis VAZ, 1931: Salminus maxillosus: Brazil. (Fig. 4-9). B = 1.5-2.5 x
0.4-0.6; OS = 0.13-0.14; Ph = 0.082 x 0.04; Egg = 33-37 x 16 x 18 µm.
Witenbergia VAZ, 1932
Body elongated, expanded posteriorly. Oral sucker cap-shaped; prephar-
ynx long; pharynx elongate; esophagus long; ceca short. Acetabulum
postequatorial. Testes diagonal; near posterior extremity; cirrus sac absent;
seminal vesicle long, sinuous; genital pore preacetabular. Ovary median,
pretesticular, seminal receptacle preovarian; vitelline follicles lateral, ex-
tend from acetabulum to posterior extremity; uterus extensive, eggs small.
Intestine of fish.
W.witenbergi VAZ, 1932: Pseudoplatystoma tigrium: Brazil. (Fig. 4-8). B = 2-3.3 x
0.2-0.44; OS = 0.14-0.16 x 0.12-0.13; Ph = 0.11 x 0.05; A = 0.13-0.16; Egg
= 41-45 x 17 x 18 µm.
Paramphistomata SZIDAT, 1936. (The classification of the amphistomes used here follows
that of SEY, 1991).
Cladorchiidae SOUTHWELL & KIRSHNER, 1932
Body elongate, oval, pear shaped, thick, rarely flattened. Acetabulum
terminal or ventro-terminal. Pharynx muscular, with dorsolateral appendag-
es; esophagus with or without muscular bulb; ceca of variable length. Testes
two, inter or extracecal; cirrus sac present. Ovary post-testicular; genital pore
near intestinal bifurcation; uterine coils mainly post-testicular; vitellaria
follicular or compact, lateral. Eggs large, with or without miracidia. Intestinal
parasites of fish, amphibians, reptiles and rarely mammals.
Alphamphistoma THATCHER & JÉGU, 1996
Body elongate, narrow, deeply concave ventrally, with lateral margins folded
in. Pharynx small, with external diverticula; esophagus without muscular
bulb; ceca slender, shorter than body. Acetabulum subterminal, without
posterior indentation on rim. Testes lobate, tandem, in anterior half of
body; cirrus sac in anterior one-third of body; genital pore immediately
post-bifurcal. Ovary spherical, on mid-line, in posterior one-third of body;
vitellaria follicular, anterolateral to ovary, not reaching level of posterior
testis; uterus intercecal, eggs numerous. Intestinal parasites of freshwater
fish. Type species: Alphamphistoma canoeforma THATCHER & JÉGU, 1996.
A. canoeforma THATCHER & JÉGU, 1996: Mylesinus paraschomburgkii: Uatumã,
Pitinga, Capucapu, Trombetas, Jari and Araguari Rivers, Amazonas and
Pará States, Brazil. (Figs. 4-61 A-B & 4-88). B = 3.4-5.9 x 1.5-2.9; A = 0.67-
1.2 x 0.71-1.2; Ph = 0.26-0.52 x 0.23-0.40; CS = 0.26-0.51 x 0.10-0.33;
Eggs = 103 -129 x 51-69 µm.
Anavilhanatrema THATCHER, 1992
Body large, cylindrical, slightly flattened and with a collar-like anterior
expansion. Pharynx small, terminal, with external diverticula; esophagus
long, without muscular bulb; ceca of moderate diameter, terminating
146 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
near acetabulum. Acetabulum small to medium size, subterminal. Testes
large, lobate, tandem, pre-equatorial; cirrus sac small, ovoid, containing
sinuous tubular seminal vesicle; genital pore at level of bifurcation.
Ovary lobate, lateral to midline, near acetabulum; vitallaria follicular,
dorso-lateral to ceca, extensive, from cecal ends to posterior testis;
uterus largely intercecal, uterine seminal receptacle present near ovary;
eggs numerous. Circulatory sysem present. Excretory vesicle saccular;
pore dorsal. Intestinal parasites of freshwater fish. Type species: Anavil-
hanatrema robuusta THATCHER, 1992.
A. robusta THATCHER, 1992: Pristobrycon striolatus: Anavilhanas Islands, Rio
Negro, Amazonas State, Brazil. (Figs. 4-86 & 4-97). B = 4.6-12.0 x 1.9-3.7;
A = 0.71-1.6 long and 0.82-1.5 wide; Ph = 0.65 x 0.62; CS = 0.63 x 0.45;
Eggs = 84-112 x 42-70 µm.
Annelamphistoma THATCHER, SEY & JÉGU, 1996:
Body subcylindrical, flattened dorsally, convex ventrally, tapering anteriorly,
with five pairs of muscular puckers dorsally and one lateral expansion on
either side of acetabulum; tegument smooth dorsally and papillate ventrally.
Acetabulum hemispherical, subterminal. Pharynx with large external diver-
ticula, mouth terminal; esophagus short, bulb small; ceca long, slender.
Testes two, large, weakly lobate, inter and extracecal, tandem, in middle third
of body; cirrus sac large, ovoid; genital atrium and small genital sucker
present; genital pore median, immediately postbifurcal. Ovary spherical to
ovoid, submedian, near level of cecal ends; vitellaria chain-like, anterolateral
to ovary and ventral to ceca, extending anteriorly to near posterior testis;
uterus largely intercecal, eggs large. Lymphatic system present. Excretory
vesicle saccular, pore dorsal. Intestinal parasites of freshwater fish. Type
species: Annelamphistoma elegans THATCHER, SEY & JÉGU, 1996.
A. elegans THATCHER, SEY & JÉGU, 1996: Myleus (Myloplus)rubripinnis and M. (M.)
asterias. Jatapu River, Amazonas State & Guaporé River, Rondonia State,
Brazil. (Figs. 4-67 A-C, 4-77, 4-79 & 4-89). B = 2.5-3.1 x 0.75-1.3; A =
0.36-0.53 x 0.42-0.50; Ph = 0.31-0.56 x 0.18-0.22; CS = 0.14-0.19 x 0.08-
0.17; Eggs = 116-138 x 50-60 µm.
Betamphistoma THATCHER & JÉGU, 1996
Body small, flattened, tapered anteriorly. Acetabulum terminal, with
posterior indentation on inner rim. Pharynx with external diverticula;
esophagus without bulb; ceca slender, shorter than body. Testes lobate,
parallel, equatorial ; cirrus sac with heavymuscular walls; genital pore
postbifurcal; small spherical genital atrium present. Ovary small, subspher-
ical, on mid-liine between cecal ends; vitellaria of few small follicles, lateral
to ovary; uterus intercecal, eggs numerous. Intestinal parasites of freshwa-
ter fish. Type species: Betamphistoma jariense THATCHER & JÉGU, 1996.
B. jariense THATCHER & JÉGU, 1996: Mylesinus paraschomburgkii: Jari River, Pará State,
Brazil. (Fig. 4-55). B = 2.8-4.1 x 1.1-1.6; A = 0.34-0.57 x 0.60-0.76; Ph = 0.26-
0.34 x 0.16-0.24; CS =0.22-0.37 x 0.15-0.38; Eggs = 85-103 x 30-40 µm.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 147
Colocladorchis THATCHER, 1979
Body slightly flattened, tapered anteriorly, rounded posteriorly; tegument
unspined. Oral sucker terminal, spherical, with small internal diverticula;
esophagus long, with muscular bulb; ceca thick, short, terminate near
equator. Acetabulum large, postero-ventral. Testes weakly lobate, parallel,
ventro-lateral to ceca in midbody; cirrus sac small, median, genital pore
median, near bifurcation. Ovary spherical, median, between testes, vitelline
gland of two irregular masses, postero-dorsal to testes; uterus occupying
space between ovary and acetabulum, contains eggs proximally and
miracidia distally (ovoviviparous). Circulatory system present. Excretory
vesicle sacular, pore dorsal. Intestine of freshwater fish.
C. ventrastomis THATCHER, 1979: Prochilodus reticulatus: Colombia. (Fig. 4-40). B
= 0.71-1.53 x 0.40-0.89; OS = 0.1-0.19; A = 0.30-0.58; CS = 0.072-0.12 x
0.06-0.096; Egg = 60-66 x 36-49 µm; Miracidium = 85-142 x 53-95 µm.
Curimatrema THATCHER, 2000.
Body small, pyriform, with anterior expansion and large subterminal
acetabulum. Pharynx large, with prominent external diverticula. Esopha-
gus short; ceca reaching acetabulum. Testes spherical, diagonal, equatorial
or pre-equatorial; cirrus sac absent; large genital sucker present near
intestinal bifurcation. Ovary spherical, post-testicular, lateral to mid-line;
vitelline glands comprising few follicles on either side near cecal ends; eggs
large, few in number. Intestinal parasites of freshwater fishes. Type
species: Curimatrema microscopica THATCHER, 2000.
C. microscopica THATCHER, 2000: Curimata vittata: Porto Novo, Rondônia State,
Brazil. (Fig. 4-64). B = 0.61-0.77 x 0.35-0.39; A = 0.24-0.26 in diameter; Ph
= 0.15-0.18 x 0.11 -0.17; Eggs = 88-120 x 44-77.
Dadayius FUKUI, 1929
Body elongate, conical. Acetabulum massive, ventroterminal, with trans-
verse tegumental ridges on interior bottom surface. Pharynx with external
diverticula; mouth terminal; esophagus slender, with bulb; ceca reaching
acetabulum. Testes rounded to oval, not lobate; cirrus sac absent; genital
sucker present; genital pore at level of bifurcation. Ovary subspherical,
anterior or dorsal to acetabulum; vitelline follicles lateral, between ovary
and posterior testis; uterus intercecal; eggs large. Intestinal parasites of
South American freshwater fishes. Type species: Dadayius marenzelleri
(DADAY, 1907) FUKUI, 1929.
D. marenzelleri (DADAY, 1907): Mylossoma sp.: Brazil. (Fig. 4-28). B = 4-6 x 2-3;
OS = 0.5-0.8 x 0.4-0.60; Diverticula = 0.25-0.30; A = 1.2-2; E = 0.7; EB =
0.22; GS 0.37; Egg = 140-145 x 60-80 µm.
D. pacuensis THATCHER, SEY & JÉGU, 1996: Myleus (Myloplus) rubripinnis and M.
(M.) asterias: Jatapu River, Amazonas State & Guaporé River, Rondonia
State, Brazil. (Figs. 4-65 A-B, 4-73, 4-76 & 4-84). B = 1.5-3.0 x 1.1-1.9; A =
1.1-1.4 x 1.0-1.5; Ph = 0.30-0.60 x 0.34-0.43; GS = 0.31-0.43 x 0.34-0.69;
Eggs 69-86 x 26-43 µm.
148 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
Dadaytrema TRAVASSOS, 1931, THATCHER, 1979.
Body elongate, cylindrical. Oral sucker pyriform, with posterior diverticu-
la; mouth terminal, surrounded by small papillae and with several rings of
papillae posterior to mouth; esophagus long, with small bulb; ceca long
sinuous. Acetabulum subterminal, with papillate floor and posteromedian
notch in rim. Testes deeply lobed, pre-equatorial, intercecal, but invading
cecal areas, genital sac containing seminal vesicle; cirrus absent; genital
pore median, post-bifurcal, contained in shallow sucker. Ovary spherical,
median, near acetabulum; vitelline follicles small, few, lateral to ovary and
dorsal to cecal ends; uterus intercecal, filling space between ovary and
testes, with eggs proximally and miracidia distally (ovoviviparous). Circula-
tory system of longitudinal tubes with sinuses near suckers. Excretory
vesicle saccular, pore dorsal. Intestine of freshwater fish.
D. elongata VAZ, 1932: Myleus sp.: Brazil. B = 3-4.5 x 0.95-1.7; OS = 0.1x 0.7;
Diverticula = 0.2-0.35 x 0.1; A = 0.5-0.7; Egg = 115-153 x 49-70 µm.
D. oxycephala (DIESING, 1836) TRAVASSOS, 1931, THATCHER, 1979: Colossoma
bidens: Brazil (Fig. 4-37). B = 3.0-5.0 x 1.1-1.3; OS = 0.15-0.25 x 0.09-0.18;
Diverticula = 0.18-0.22 x 0.14-0.18; A = 0.56-0.90; GS = 0.18-0.40 x 0.11-
0.27; Egg = 90 x 60 µm. Miracidium = 140-190 x 85-96 µm.
Dadaytremoides THATCHER, 1979
Body flattened, widest at equator, tapering towards extremities, unspined.
Oral sucker large, rounded, with large diverticula; esophagus long, bulb
prominent; ceca thick, long. Acetabulum subterminal. Testes weakly
lobate, diagonal, in midbody; genital pore postbifurcal, with small sucker.
Ovary spherical, median, between cecal ends; vitelline follicles few, dorsal
to cecal terminations; uterus filling space between ovary and testes; with
eggs proximally and miracidia distally (ovoviviparous). Circulatory system
with longitudinal stems and sinuses near suckers. Excretory vesicle
saccular, pore dorsal. Intestine of freshwater fish.
D. grandistomis THATCHER, 1979: Astyanax fasciatus and Chaetostomus leucomelas:
Colombia: (Fig. 4-38). B = 1.9-4.0 x 0.75-1.3; OS = 0.22-0.64; Diverticula
= 0.14-0.22 x 0.09-0.14; A = 0.35-0.54; GS = 0.14-0.23 x 0.09-0.16; Egg =
72-90 x 36-45 µm; Miracidia = 95-110 x 41-62 µm.
Deltamphistoma THATCHER & JÉGU, 1996
Body cylindrical, slightly flattened. Acetabulum small, subterminal. Phar-
ynx with external diverticula; esophagus with muscular bulb; ceca shorter
than body, usually not reaching ovary. Testes large, overlapping ceca,
bluntly lobate, tandem, pre-equatorial; cirrus thin-walled; genital pore
post-bifurcal, small atrium present. Ovary subspherical, lateral to mid-line,
in posterior one-fourth of body; vitelline follicles on either side of body,
near ceca, extend from ovary to posterior testis; uterus intercecal, eggs
numerous. Intestinal parasites of freshwater fish. Type species: Deltamphis-
toma pitingaense THATCHER & JÉGU, 1996.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 149
D. pitingaense THATCHER & JÉGU, 1996: Mylesinus paraschomburgkii: Uatumã,
Pitinga and Capucapu Rivers, Amazonas State, Brazil. (Fig. 4-56). B = 3.1-
4.1 x 1.0-1.5; A = 0.43-0.57 x 0.52-0.60; Ph = 0.26-0.34 x 0.21-0.26; CS =
0.22-0.39 x 0.13-0.34; Eggs = 95-120 x 34-52 µm.
Doradamphistoma THATCHER, 1999
Body elongate, flattened, sides nearly parallel, extremities bluntly rounded.
pharynx large, with prominent external diverticula; esophagus long, bulb
present; ceca reaching to near acetabulum. Acetabulum small, subterminal.
Testes diagonal, equatorial or pre-equatorial; cirrus sac small, subspherical;
genital pore postbifurcal. Ovary ovoid, postequatorial; vitellaria consisting
of few large follicles lateral to ovary and extracecal; uterus extensive, with
ascending and descending loops; eggs numerous; ovoviviparous. Excretory
vesicle saccular, pore dorsal. Intestinal parasites of Amazonian catfishes.
Type species: Doradamphistoma bacuensis THATCHER, 1999.
D. bacuensis THATCHER, 1999: Megalodoras irwini: Amazon River, near Manaus,
Amazonas State, Brazil. (Fig. 4-81 & 4-99). B = 6.0-9.6 x 1.8-3.1; Ph = 0.83-
1.3 x 0.62-0.83; CS = 0.20-0.26 x 0.20-0.26; Eggs =132-191 x 88-110 µm.
GamamphistomaTHATCHER & JÉGU, 1996
Body small, little flattened, with collar-like expansion anteriorly. Pharynx
with external diverticula; esophagus short, with muscular bulb; ceca long.
Acetabulum large, with posterior notch on inner rim. Testes large, lobate,
tandem, pre-equatorial; cirrus sac ovoid, thin-walled; genital pore at level
of intestinal bifurcation, small genital atrium present. Ovary spherical, on
mid-line near acetabulum; vitellaria follicular, lateral to ovary, of limited
extent; uterus intercecal. Eggs numerous. Intestinal parasites of freshwater
fish. Type species: Gamamphistoma collaris THATCHER & JÉGU, 1996.
G. collaris THATCHER & JÉGU, 1996: Mylesinus paraschomburgkii: Uatumã, Pitinga
and Capucapu Rivers, Amazonas State & Jari River, Pará State, Brazil. (Fig.
4-57). B = 1.2-2.2 x 0.6-0.9 ; A = 0.39-0.58 x 0.48-0.60; Ph = 0.19-0.26 x
0.14 -0.24; CS = 0.13-0.22 x 0.08-0.17; Eggs = 97-127 x 46-92 µm.
Inpamphistoma THATCHER, SEY & JÉGU, 1996
Body elongate, flattened, tapering anteriorly, concave dorsally and convex
ventrally, with one pair of muscular puckers near oral sucker and one
lateral expansion on either side of acetabulum; tegument smooth dorsally
and papillate ventrally. Acetabulum hemispherical, subterminal. Pharynx
terminal, with external diverticula; esophagus short, bulb small; ceca long,
slender. Testes two, large lobate, tandem, largely intercecal, in middle third
of body; cirrus sac ovoid; small genital atrium present; genital pore
median, immediately postbifurcal. Ovary ovoid or weakly lobate, submedi-
an, near level of cecal ends; vitellaria follicular, of limited extent, antero-
lateral to ovary and ventral to ceca; uterus largely intercecal, proximal eggs
small, distal eggs larger. Lymphatic system present. Excretory vesicle
saccular, pore dorsal. Intestinal parasites of freshwater fish. Type species:
Inpamphistoma papillatum THATCHER, SEY & JÉGU, 1996.
150 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
I. papillatum THATCHER, SEY & JÉGU, 1996: Myleus (Myloplus) asterias: Jatapu and
Uatumã Rivers, Amazonas State and Guaporé River, Rondônia State,
Brazil. (Fig. 4-66). B = 1.8-3.8 x 0.85-1.3; A = 0.43-0.81 x 0.46-0.81; Ph =
0.18-0.29 x 0.11-0.21; CS = 0.08-0.26 x 0.03-0.11; Proximal eggs = 55-94 x
33-44 µm; Distal eggs = 121-154 x 66-94.
Kalitrema TRAVASSOS, 1933
Body flattened, unspined, with circular groove at level of esophagus, and
deep indentation at posterior extremity. Oral sucker large, with internal
diverticula; esophagus long, without bulb; ceca medium long. Acetabulum
small, in posterior indentation. Testes small, weakly lobate, parallel, extrace-
cal, in anterior third; cirrus sac absent; small genital sucker present, posterior
to tegumental groove. Ovary small, spherical, median, posterior to cecal
ends; vitelline follicles few, near cecal termination; uterus intercecal, from
genital sucker to beyond ovary; with eggs proximally and miracidia distally
(ovoviviparous). Excretory vesicle spherical, pore dorsal. Intestine of fish.
K. kalitrema TRAVASSOS, 1933: Hypostomus punctatus: Brazil. (Fig. 4-39). B = 7-
8.7 x 2.6-3; OS = 0.36-0.39; Diverticula = 0.13; A = 0.76-0.78; Miracidia =
160-168 x 96-112 µm.
Micramphistoma THATCHER, 1992
Body medium sized, somewhat flattened, with parallel sides, dorsally concave.
Pharynx small, subspherical, without diverticula; esophagus long, without
muscular bulb; ceca slender, medium long. Acetabulum, small, subspherical,
subterminal. Testes spherical to ovoid, nearly parallel, near intestinal bifurca-
tion; male genital sac subovoid, between testes; genital pore immediately
postbifurcal. Ovary spherical, near acetabulum, lateral to midline; vitellaria
consisting of few large follicles, dorso-lateral to ceca, in middle third of body;
uterus largely intercecal; eggs small numerous. Circulatory system present.
Excretory vesicle saccular, pore dorsal. Intestinal parasites of freshwater fish.
Type species: Micramphistoma ministoma THATCHER, 1992.
M.ministoma THATCHER, 1992: Hypopomus sp.: Guaporé River, Rondônia State,
Brazil. (Figs. 4-80 & 4-95). B = 4.5-5.6 x 2.0-2..4; A = 0.50-0.59 x 0.52-
0.60; Ph = 0.43-0.56 x 0.42-0.49; Male genital sac = 0.21-0.38 x 0.27-0.38;
Eggs = 88-110 x 50-60 µm.
Myleustrema THATCHER & JÉGU, 1998
Body elongate, flattened, concave dorsally and convex ventrally, with
circlets of papillae around anterior extremity. Pharynx small, terminal,
with external diverticula; esophagus long, with small bulb; ceca slender,
not reaching acetabulum. Acetabulum small, terminal, with circle of
papillae around aperture. Testes weakly lobate, tandem, equatorial; cirrus
sac ovoid, with heavy muscular walls, contains internal seminal vesicle;
genital pore postbifurcal; small genital atrium present. Ovary subspherical,
near cecal ends in posterior quarter of body; vitellaria of limited extent,
anterolateral to ovary; uterus intercecal; eggs few. Intestinal parasites of
fish. Type species: Myleusnema concavatum THATCHER & JÉGU, 1998.
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 151
M.concavatum THATCHER & JÉGU, 1998; Myleus ternetzi: French Guiana (Fig. 4-
59). B = 2.8-3.2 x 1.0-1.2; Ph = 241-258 x 146-181; A = 172-301 long and
344-430 wide; Eggs = 115-138 x 51-64 µm.
Pacudistoma THATCHER,1992
Body large, cylindrical, little flattened. Pharynx large, terminal, with
prominent internal diverticula; esophagus long, muscular, without bulb,
cec of medium diameter, long. Acetabulum medium sized, subtermi-
nal. Testes large, lobate, tandem, pre-equatorial; cirrus sac small, ovoid,
containing saccular seminal vesicle; genital pore immediately postbifur-
cal, provided with large, muscular genital sucker. Ovary small, spheri-
cal, near acetabulum; vitellaria of small follicles, ventral to ceca,
between ovary and posterior testis; uterus largely intercecal, uterine
seminal receptacle present. Exccretory vesicle saccular, pore dorsal.
Intestinal parasites of freshwater fishes. Type species: Pacudistoma
turgida THATCHER, 1992.
P. turgida THATCHER, 1992; Myleus pacu: Jamari River, Rondônia State, Brazil
(Fig. 4-82). B = 7.1-10.1 x 3.1-3.9; Ph = 1.1-1.4 wide; A = 1.5-1.9 long x
1.4-1.7 wide; Eggs = 98-112 x 56-70 µm.
P. guianensis THATCHER & JÉGU, 1998; Myleus ternetzi: Sinnamary River, French
Guiana (Fig. 4-60). B = 2.8-3.2 x 1.0-1.1; Ph = 241-258 long x 146-181
wide; A = 172-301 long x 344-430 wide; Eggs = 115-138 x 51-64 µm.
Pronamphistoma THATCHER, 1992
Body small, stout, with anterior collar-like expansion. Acetabulum large,
round, subterminal. Pharynx large, terminal, subspherical, with internal
diverticula; esophagus short, bulb ovoid; ceca thick, long, reaching acetab-
ulum. Testes subspherical, entire, in middle third of body; cirrus sac ovoid,
containing saccular seminal vesicle; genital pore postbifurcal. Ovary
spherical, submedian, near acetabulum; vitellaria consisting of follicles in
linear rows that form fan-like configurations on each side of ovary; uterus
short, with few large eggs. Circulatory system present. Excretory vesicle
saccular, pore dorsal. Intestinal parasites of freshwater fishes. Type
species: Pronamphistoma cichlasomae THATCHER, 1992.
P. cichlasomae THATCHER, 1992: Cichlasoma severum: Guaporé River, Rondônia
State, Brazil. (Figs. 4-85 & 4-92). B = 0.69-1.12 x 0.42-0.76; A = 0.26-0.45
x 0.28-0.49; Ph = 55-82 µm in diameter; CS = 55-112 µm in diameter;
Eggs = 82-110 x 45-65 µm.
Pseudocladorchis DADAY, 1907
Body elongate, elliptical. Oral sucker terminal, with papillae around
mouth; esophagus without bulb; ceca long. Acetabulum large, ventro-
terminal, with median notch on posterior inner margin of rim. Testes
nearly parallel, in midbody; cirrus sac present; genital pore near bifurca-
tion. Ovary between cecal ends; vitelline follicles extending along ceca
from testes; uterus intercecal. Excretory vesicle between ovary andacetabulum, pore dorsal. Intestine of freshwater fish.
152 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
P. cylindricus (DIESING, 1836) DADAY, 1907: Mylossoma aureum. Pterodoras granulo-
sus, Colossoma bidens and Pimelodus ornatus: Brazil. (Fig. 4-30). B = 4-10 x 1.5-
3.2; OS = 0.6-1.2 x 0.6-1.3; A = 0.5-2.5; Egg = 90-100 x 60-80 µm.
P. ferrumequinum (DIESING, 1836) STUNKARD, 1925: Pterodoras granulosus and
Doras dorsalis: Brazil. B = 5.5-11.5 x 3.2-5.4; OS = 1.6-2 x 1-1.6; Diverticula
= 0.35-0.45; Egg = 80 x 50 µm.
Pseudodiplodiscus MANTER, 1962
Body small, conical. Oral sucker terminal, with small diverticula; esopha-
gus with bulb; ceca short. Acetabulum large, ventro-terminal. Testis single,
in midbody; cirrus sac small; genital sucker small, near bifurcation. Ovary
irregular, submedian, preacetabular; vitellaria lateral, from cecal ends to
ovary; uterus winding between testis and acetabulum. Excretory vesicle
saccular, pore dorsal. Intestine of freshwater fish.
P. cornu (DIESING, 1939) MANTER, 1962: Doras dorsalis: Brazil. (Fig. 4-29). B =
4-4.3 x 2-2.2; OS = 0.25-0.40; A = 2-2.2; Egg = 130-140 x 60-70 µm.
Travassosinia VAZ, 1932
Body cylindrical. Oral sucker terminal, with papillae around mouth;
esophageal bulb small; ceca medium long. Acetabulum large, ventro-
terminal. Testes tandem, in midbody; genital pore median, postbifurcal.
Ovary median, post-testicular; vitelline follicles lateral along post-testicular
portions of ceca; uterus inter- and extracecal. Excretory pore dorsal.
Intestine of freshwater fish.
T. dilatata (DADAY, 1907) VAZ, 1932: Colossoma bidens and Myleus sp.: Brazil.
(Fig. 4 -27). B = 8-10 x 4-5; OS = 1.2-1.3; Egg = 115-150 x 57-80 µm.
Zetamphistoma THATCHER & JÉGU, 1996
Body small, wide, flattened, convex on both surfaces, thinner peripherally.
Pharynx with external diverticula; esophagus slender, with small bulb; ceca
shorter than body. Acetabulum terminal, with indentation on posterior
inner rim. Testes lobate, tandem, pre-equatorial, intercecal; cirrus sac
ovoid, with thin walls; genital pore post-bifurcal. Ovary subspherical, on
mid-line, near acetabulum; vitellaria of few follicles on either side of
ovary; uterus intercecal, eggs numerous, small proximally, larger distally.
Intestinal parasites of freshwater fish. Type species: Zetamphistoma compacta
THATCHER & JÉGU, 1996.
Z. compacta THATCHER & JÉGU, 1996: Mylesinus paraschomburgkii: Trombetas River,
Pará State, and Araguari River, Amapá State, Brazil. (Figs. 4-63 A-B & 4-83). B
= 2.5-3.9 x 1.5-2.5; A = 0.48-0.64 x 0.61-0.94; Ph = 0.33-0.37 x 0.16-0.26; CS
= 0.13-0.34 x 0.086-0.22; Eggs = 92-115 x 46-58 µm.
Sanguinicolidae GRAFF, 1907
Body flattened, elongate or lanceolate. Oral sucker absent or rudimentary;
pharynx absent; esophagus long; gut X or H shaped. Acetabulum absent.
Testes single, double, branched or follicular; between ovary and bifurca-
tion; cirrus sac present or absent; seminal vesicle usually present; genital
pores dorsal, posterior, submarginal; male pore posterior to female. Ovary
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 153
median, lobed or two-winged; near posterior extremity; vitellaria extensive;
uterus limited; eggs not operculate. Blood-vascular system of fish.
Sanguinicola PLEHN, 1905
Body lanceolate, with marginal striations. Oral sucker absent; esophagus
long; gut X or H shaped, sometimes with five branches. Acetabulum absent.
Testes in two rows, in medium field, between ovary and intestine; cirrus sac
present; genital pores near posterior extremity. Ovary of two symmetrical
wings, in posterior half of body; vitellaria lateral; uterus with only one egg;
egg with lateral projections. Vascular system of freshwater fish.
S. argentinensis, SZIDAT, 1951; Prochilodus platensis: Argentina. B = 1.6-1.7 x 0.37;
Ph = 0.02 x 0.015; E = 0.45; Egg = 37 x 31 µm.
S. coelomicola (SZIDAT, 1951): Iheringichthys labrosus: Argentina. (Fig. 4-32). B =
1.6 x 0. 55; E = 0.5-0.6; Egg = 11-12 x 6-7 µm.
Zonocotylidae PADILHA, 1978
Body elongate, widened posteriorly. Oral sucker terminal; esophagus long;
ceca short, saccular. Acetabulum subterminal, with thin walls and trans-
verse corrugations on floor. Testis single, median, postequatorial; cirrus
sac absent; genital pore median, midway between oral sucker and bifurca-
tion. Ovary spherical or oval, submedian, between testis and acetabulum;
vitellaria of two compact masses, one on either side of testis or ovary;
uterine coils extensive posteriorly, with eggs proximally and miracidia
distally (ovoviviparous). Circulatory system well developed. Excretory
vesicle saccular, pore dorsal. Intestine of freshwater fish.
Zonocotyle TRAVASSOS, 1948, PADILHA, 1978
Body elongate, flattened, widened posteriorly; tegument smooth, thick.
Oral sucker terminal; esophagus long, dilated posteriorly, without bulb;
ceca short, thick, with microvilli on interior walls. Testis irregularly
rounded, median, between cecal ends. Ovary spherical submedian, post-
testicular; vitelline glands of two compact masses, one on either side of
ovary; uterus extensive, with eggs proximally and miracidia distally
(ovoviviparous). Circulatory system of one continuous tube which loops
laterally on both sides, between suckers. Excretory vesicle small, spherical,
pore and vesicle both dorsal to acetabulum. Intestine of freshwater fish.
Z. bicaecata TRAVASSOS, 1948, PADILHA, 1978: Curimata elegans and C. gilberti:
Brazil. (Fig. 4-41). B = 2.65-5.23 x 0.73-1.38; OS = 0.19-0.48 x 0.31-0.55; E
= 0.70-1.56; A = 0.99-1.8 x 0.8-1.7 (with 11-14 ridges on floor);
Miracidium = 140-210 x 50-120 µm.
Zonocotyloides PADILHA, 1978
Similar to Zonocotyle except: body larger; acetabulum relatively smaller;
vitellaria of two compact V-shaped masses, one on either side of testis and
united anterior to that organ. Ovoviviparous. Intestine of freshwater fish.
Z. haroltravassossi PADILHA, 1978: Curimata gilberti: Brazil. (Fig. 4-42). B = 4.75-
7.4 x 1.6-2.1; OS = 0.36-0.50 x 0.47-0.60; E = 1.4-2.3; A = 1.2- 1.87 x 1.3-
1.56 (with 9-10 ridges on floor).
154 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
VIII. Plates of Trematoda (Digenea) (Figs. 4-1 to 4-99)
4-1. Acanthostomum gnerii: entire (ventral; AP = anal pore; CS = circumoral spine; EP = excretory
pore; GP = genital pore; IC = intestinal crus; MO = mouth; OS = oral sucker; OV = ovary; PH =
pharynx; PP = prepharynx; SR = seminal receptacle; SV = seminal vesicle; TE = testis; UE = uterus
with eggs; VG = vitelline gland; VS = ventral sucker (= acetabulum).
4-1
0.5 m
m
MO
CS
OS
PP
PH
IC
GP
VS
UE
SV
VG
OV
SR
TE
AP
EP
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 155
4-2. Amazonadistoma negrensis: entire (ventral); EB = excretory bladder; EP = excretory pore; GS =
genital sucker; IC = intestinal crus with diverticula and microvilli; MG = MEHLIS’ gland; OS = oral
sucker; OV = ovary; SV = seminal vesicle; TE = testis; TR = tegumental ridge; UE = uterus with
eggs; VG = vitelline gland; VS = ventral sucker (= acetabulum).
4-2
1.0 m
m
OS
GS
SV
VS
MG
OV
VG
TE
UE
IC
TR
EB
EP
156 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-3. Brasicystis bennetti: entire (ventral); OV = ovary; SR = seminal receptacle; TE = testis; UE =
uterus with eggs; VG = vitelline gland.
1.5 m
m
4-3
SR
OV
TE
UE
VG
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 157
4-4. Bellumcorpus major; 4-5. Paurorhynchus schubarti; 4-6. Prosorhynchus costai.
4-4
4-5
4-6
158 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-7. Prosthenhystera obesa; 4-8. Witenbergia witenbergia.
4-7
4-8
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 159
4-9. Cladocystis intestinalis; 4-10. Crepidostomum macrorchis; 4-11.Creptotrema creptotrema; 4-12. Eocreadium
internedium.
4-9
4-10
4-11
4-12
160 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-13. Antorchis lintoni; 4-14. Procaudotestis uruguayensis.
4-13
4-14
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 161
4-15. Caballerotrema arapaimense; 4-16. Kalipharynx piramboae; 4-17. Magnivitellium simplex.
4-15
4-16
4-17
162 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-18. Crassicutis cichlasomae.
4-18
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 163
4-19
4-20
4-21
4-19. Dendrorchis neivai; 4-20. Parspina argentinensis; 4-21. Halipegus dubius.
164 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-22. Iheringtrema iheringi; 4-23. Paleocryptogonimus claviformis.
4-22
4-23
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 165
4-24. Megacoelium spinicavum: A. ventral; B. lateral.
4-24 A 4-24 B
166 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-25. Phyllodistomum duncani.
4-25
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 167
4-26. Chalcinotrema lucieni.
4-26
168 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-27. Travassosinia dilatata; 4-28. Dadayius marenzelleri; 4-29. Pseudodiplodiscus cornu; 4-30. Pseudocladorchis
cylindricus.
4-27 4-28
4-29 4-30
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 169
4-31. Lecithobotrioides mediacanoensis; 4-32. Sanguinicola coelomicola.
4-31 4-32
170 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-33. Chalcinotrema ruedasueltensis.
4-33
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 171
4-34. Saccocoelioides leporinodus.
4-34
172 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-35. Saccocoelioides saccodontis.
4-35
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 173
4-36. Paralecithobotrys brasiliensis.
4-36
174 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-37. Dadaytrema oxycephala; 4-38. Dadaytremoides grandistomis.
4-37 4-38
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 175
4-39. Kalitrema kalitrema (scale = 3 mm).
4-39
176 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-40. Colocladorchis ventrastomis.
4-40
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 177
4-41. Zonocotyle bicaecata; 4-42. Zonocotyloides haroltravassosi.
4-41
4-42
178 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-43. Saccocoelioides magnorchis.
4-43
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 179
4-44. Curumai curumai; 4-45. Denticauda quadrangulata; 4-46. Pseudoparabaris parabaris.
4-44
4-45
4-46
180 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-47. Brasicystis bennetti: photo of entire specimen; 4-48. Diplostomula of Strigeoidea; 4-49.
Diplostomula: close up view; 4-50. Encysted metacercaria of Ascocotyle sp. (“black spot”).
4-49 4-50
4-47 4-48
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 181
4-51 to 4-54. Tumors in Chaetobranchus semifasciatus provoked by trematode metacercariae: 4-51. large
tumor and satellite tumor in gills (operculum removed); 4-52. simple tumor in gill filament with
metacercaria in center; 4-53. swollen gill filament containing metacercaria; 4-54. multiple branching
of gill filament.
4-51 4-52
4-53 4-54
182 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-55. Betamphistoma jariense (scale = 1000 µm); 4-56. Deltamphistoma pitangaense (scale = 1000 µm); 4-
57. Gamadistoma collaris (scale = 1000 µm); 4-58. Saccocoelioides rotundus (scale = 250 µm).
4-55
4-56
4-57
4-58
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 183
4-59. Myleustrema concavatum: A. ventral (scale = 1000 µm); B. genital complex (scale = 100 µm).
4-59 A
B
184 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-60. Pacudistoma guianensis from Myleus ternetzi. A-C growth series all to same scale = 1000 µm.
4-60 A
B
C
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 185
4-61. A. Alphamphistoma canoeforma (scale = 1000 µm); B. same - terminal genitalia (scale = 250 µm);
4-62. A. Pseudocladorchis cylindricus (scale 1000 µm); B. same - genitalia lateral (scale = 500 µm); 4-63.
Zetamphistoma compacta (scale = 1000 µm).
4-61 A
B
4-62
4-63 A
B
186 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-64. Curimatrema microscopica (scale = 500 µm).
4-64
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 187
4-65. Dadayius pacuensis: A. ventral (scale = 1000 µm); B. lateral (scale = 1000 µm).
4-65 A
B
188 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-66. Inpamphistoma papillatum (scale = 500 µm).
4-66
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 189
4-67. Annelamphistoma elegans: A. ventral (scale = 500 µm); B. dorsal (scale = 1000 µm); C. lateral
(scale = 1000 µm).
4-67 A
C
B
190 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-68. Paraproctotrema delicata; 4-69. Sphericomonorchis spinulosus; (scales = 200 µm).
4-68
4-69
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 191
4-70. Genolopa magnacirrus; 4-71. Paraproctotrema delicata; 4-72. Genolopa magnacirrus; (scales = 200 µm).
4-70
4-71
4-72
4-70
192 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
Dadayius pacuensis: 4-73. ventral (scale = 1000 µm); 4-74. mouth (scale = 100 µm); 4-75. interior of
acetabulum (scale = 200 µm); 4-76. genital pore (scale = 50 µm); scanning electron micrographs.
4-73
4-74
4-764-75
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 193
Annelamphistoma elegans: 4-77. dorsal (scale = 500 µm); 4-78. papilla around acetabulum (scale = 3
µm); 4-79. papillae around mouth (scale = 3 µm); scanning electron micrographs.
4-77
4-78
4-79
194 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-80. Micramphistoma ministoma (scale = 500 µm); 4-81. Doradamphistoma bacuensis (scale = 1000 µm); 4-
82. Pacudistoma turgida (scale = 1000 µm); 4-83. Zetamphistoma compacta (scale = 1000 µm); 4-84. Dadayius
pacuensis (scale = 500 µm).
4-80 4-81 4-82
4-83 4-84
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 195
4-85. Pronamphistoma cichlasomae (scale = 1000 µm); 4-86. Anavilhanatrema robusta (scale = 500 µm); 4-
87. Dadaytrema oxycephala (scale = 1000 µm); 4- 88. Alphamphistoma canoeforma (scale = 1000 µm); 4-89.
Annelamphistoma elegans (scale = 1000 µm).
4-87
4-86
4-88 4-89
4-85
196 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-90. Prosorhynchus piranhas (scale = 250 µm).
4-90
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 197
Bucephalidae: 4-91 to 4-92. Glandulorhynchus turgidus (scale = 1000 µm); Haploporidae: 4-93. Rondotrema
microvitellarum (scale = 250 µm); 4-94. Lecithobotrioides elongatus (scale = 500 µm).
4-91 4-92
4-93
4-94
198 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-95. Micramphistoma ministoma (scale = 1000 µm).
4-95
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 199
4-96 Pronampistoma cichlasomae: ventral (scale = 250 µm).
4-96
200 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-97. Annavilhanatrema robusta (scale = 2000 µm).
4-97
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 201
4-98. Bacciger pellonae (scale = 200 µm).
4-98
202 ABLA Vol. 1 – Thatcher: Parásitos de Peces Amazónicos
4-99. Doradamphistoma bacuensis; intestine of Megalodoras irwini (scale = 1 mm).
4-99
ABLA Vol. 1 – Thatcher: Amazon Fish Parasites 203
IX. Cited and general references
ASHTON, N., BROWN, N. & D. EASTY (1969): Trematode cataract