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involved in the 
developing opisthe appears to derive directly from 
or appears alongside one or more of the postoral 
somatic kineties (i.e. stomatogenic kinety) of the 
parental form and at a level destined to be slightly 
Glossary 43
posterior to the eventual fission furrow; the primor-
dial field ( anlage ) for the opisthe’s oral apparatus 
thus appears subequatorially on the ventral surface 
at a location far removed from the parental oral 
apparatus; partial or full replacement or restructur-
ing of the parental (now proter ) oral organelles, 
involving oral kinetosomes and kinetosomes 
from the anterior termination of the stomatogenic 
kinety, may occur simultaneously; characteristic 
of some hymenostomes and some spirotrichs ; it 
was formerly known as somatic-meridional stoma-
togenesis; see Amphiparakinetal , Biparakinetal , 
Monoparakinetal , Polyparakinetal , and 
Teloparakinetal (Fig. 2.11Dd, 2.11De). 
Paralabial Organ : enigmatic structure in a crypt 
near one of the adoral syncilia in certain entodini-
omorphids ; composed of pellicular folds and cilia; 
considered a kind of sensory organelle , but this 
function not proven. 
Paralorica (pl. Paraloricae ): complete lorica
reconstructed by a tintinnid during the interphase 
period because the ciliate has abandoned or lost 
its protolorica ; constructed more slowly than the 
protolorica and therefore often having a very dif-
ferent form (e.g., coxliella-form lorica of Favella
species); see Epilorica . 
Paramembranelle : specialized term for each of 
the several adoral polykinetids characteristic of free-
living heterotrichs and spirotrichs ; all its kineto-
somes are linked by similar-appearing connectives 
and its transverse microtubules are limited to the 
kinetosomes of the left (outermost, distal) row of 
its infraciliary base. 
Paramere : DNA-poor karyomere of a heter-
omerous macronucleus ; to be contrasted with the 
orthomere , the other kind of karyomere in that type 
of nucleus (Pm, Fig. 2.12r, 2.12bb). 
Paraphyletic : condition of a taxon being com-
prised of a common ancestor but only some of 
its presumed descendants; see Monophyletic and 
Polyphyletic . 
Parasitic (adj.) : see Parasitism . 
Parasitism : symbiosis in which one member, the 
parasite, lives to various degrees at the expense of 
the other member, the host ; from the point of view 
of the parasite, the association may be facultative or 
obligate; many ciliate species loosely called “para-
sitic” are more likely just exhibiting commensalism ; 
in a general way, often used (e.g., “parasitism,” “par-
asite,” and “parasitic” sensu lato ) as an admittedly 
imprecise synonym of symbiosis , symbiont , and sym-
biotic; hyperparasitism, relatively even rarer among 
ciliates, is the parasitic association of a form with a 
host (protozoan or metazoan) that is itself a parasite 
on or in still another host (e.g., the several apostome 
species that have stages on or in other apostomes , 
which themselves are parasitic on crustaceans; or 
 chonotrichs on “whale-lice” on whales). 
Parasomal Sac : small, unit membrane -lined, pit-
like invagination or diverticulum in the pellicle , 
characteristically alongside, usually to the right of, 
a ciliferous kinetosome ; a site of pinocytosis and 
exocytosis; perhaps the pellicular pore of peritrichs 
is a kind of parasomal sac (PS, Fig. 2.1B). 
Paratene : see Parateny . 
Parateny : condition or presence of recognizable 
repeating kinetid patterns at right angles to the 
longitudinal axis of the ciliate’s body, thus parallel 
to the equator or eventual fission furrow; paratenes 
superficially give the impression that the organ-
ism’s kineties run circumferentially rather than 
longitudinally in the part of the body affected (e.g., 
the anterior end of Dexiotricha , around the oral 
region on Paramecium and Disematostoma ) (Par, 
Figs. 2.3c, 2.3d, 2.3h, 2.4J, 2.4K). 
Parental Form : generalized term to denote the 
mature or about-to-divide stage (e.g., trophont-
tomont ) in the life cycle; the form capable of 
producing offspring – one or more – depending on 
the mode of fission invoked; generally, this form 
is itself lost in the process, typically by becoming 
one of the individuals of the reproduced genera-
tion; considerable morphogenesis occurs when 
the parental form persists (e.g., living to produce 
subsequent generations of filial products , as is true 
of budding in many suctorians and chonotrichs) 
and/or even dies a natural death itself in due time. 
Paroral Kinety (pl. Kineties ): see Paroral ; kinety 
should be used only for somatic structures, though 
it is sometimes used in connection with various 
oral organelles. 
Paroral : preferred term, used in a broad sense, 
for the ciliary organelle(s) lying along the right 
side or border of the oral region ; its cilia may be 
44 2. Glossary of Terms and Concepts Useful in Ciliate Systematics
undulatory or membrane-like, behaving as a single 
unit because of their fully or partially coalescent 
nature (see Undulating Membrane ); different 
types – some very likely nonhomologous – are 
recognized by their variation in the pattern and 
organization of their infraciliature (e.g., haploki-
nety or stichodyad of oligohymenophoreans, the 
sticho monad and diplostichomonad arrangements 
in spirotrichs ); other kinds of parorals may show 
additional, if minor, ultrastructural differences, but 
in all cases the topological position and the prob-
able function are at least analogous; analogues, or 
possible homologues, include endoral membrane
(e.g., in Paramecium ), undulating membrane (e.g., 
in tetrahymenines), and zeta membranoid (e.g., in 
scuticociliates) (Pa, Figs. 2.5Aa, 2.5Ac, 2.7a, 2.7b, 
2.7e, 2.7i, 2.7k). 
Paroral Membrane : see Paroral . 
Pavés : “blocks” of ciliary organelles or kinetofrag-
ments , also called pseudomembranelles , character-
istic of the frange of certain nassophoreans ; their 
infraciliary bases are particularly clearly revealed by 
methods of silver impregnation (Pav, Fig. 2.3Ai). 
PBB-complex : see Polar Basal Body-complex . 
Pecilokont : seldom used word once proposed to 
include both “cilium” and “flagellum”. 
Pectinelle : one of a circumferential band of short 
rows of closely apposed cilia oriented at an oblique 
angle to the long axis of the body; sometimes used 
to describe the composition of both the locomotor
fringe of peritrichs and the ciliary girdle of didiniid 
 haptorians . 
Pedicel : term used variously in ciliatology, but 
generally with reference to a very short attachment 
stalk , such as in certain chonotrichs . 
Peduncle : a synonym of a short stalk ; often reserved 
for long, highly visible stalks, such as those, 
not necessarily homologous organelles, found in 
many peritrichs and suctorians ; the adjectival form, 
“peduncular,” is also often used with reference to 
stalk structures (Pdc, Fig. 2.11B, 2.11C). 
Pelagic : pertaining to the open ocean beyond the 
continental slope or the “high seas” as an ecological 
habitat, in contrast to the near-shore or neritic
biotope; eupelagic, for our purposes, is essentially 
a synonym. 
Pellicle : outer “living” zone of the cortex, lying 
beneath any non-living secreted materials; com-
posed of the typical cell or plasma membrane
plus the unit membrane -lined alveoli and, often, 
the closely apposed underlying fibrous epiplasm ; 
sometimes loosely used as synonymous with cor-
tex , but the majority of the infraciliary cortical 
structures and organelles are mostly subpellicular 
in location. 
Pellicular Alveolus (pl. Alveoli ): see Alveolus, 
Pellicular . 
Pellicular Crest : see Pellicular Ridge . 
Pellicular Pore : self-explanatory term, but particu-
larly used in reference to the numerous minute open-
ings in the pellicle on the bell (and perhaps in the 
area of the scopula ) of sessiline peritrichs through 
which are secreted substances involved