A maior rede de estudos do Brasil

102 pág.
Cap 17

Pré-visualização | Página 40 de 50

p.p ., 
 Pseudocohnilembina p.p ., Schizocaryumida p.p ., 
 Urozonina p.p ., Thigmophryina p.p .) 
 Size, small to large; shape, ovoid to elongate 
ovoid, often flattened laterally, especially in sym-
biotic forms; somatic ciliation, holotrichous; oral
region, typically in anterior half, with paroral 
dikinetid shorter than other oral structures, typ-
ically by reduction of paroral a and c segments; 
no ribbed wall from paroral towards cytostome 
except in Cinetochilidae and Loxocephalidae
(see NOTE); scutica typically present, often in 
anterior part of distinct director-meridian ; most 
commonly in brackish or marine habitats, includ-
ing sand, with numerous species free-living, but 
some occurring as endocommensals in sea urchins , 
 molluscs , coelenterates , annelids , sipunculids , and 
even the sea horse while others can be facultative 
parasites; 16 families. 
NOTE : Li et al. (2006) have suggested estab-
lishment of the order Loxocephalida based on the 
sequences of the small subunit rRNA genes for 
Dexiotrichides and Cardiostomatella , two of the at 
least 14 genera that they suggest should be included 
in this order. We await additional sequence infor-
mation before recognizing this order, but note that 
Jankowski (1964) has already suggested establish-
ing the Suborder Loxocephalina . 
 Family CINETOCHILIDAE Perty 1852 
 Size, very small to small; shape, ovoid to 
ellipsoid, usually flattened, sometimes look-
ing very much like a baseball catcher’s mitt! ; 
free-swimming; somatic ciliation, sparse, limited 
to ventral surface with one or more long caudal 
cilia; oral area relatively large, midventral, with 
pronounced ribbed wall ; in stomatogenesis, oral 
polykinetids 2 and 3 originating from scutica or 
scuticovestige ; macronucleus, globular to ellip-
soid; micronucleus, present; contractile vacuole, 
present; cytoproct occupying all of director-merid-
ian area on foreshortened ventral surface of some 
species; feeding on bacteria and smaller protists; in 
freshwater and terrestrial habitats, widespread with 
fewer species from brackish or marine habitats; 
seven genera. 
 – Cinetochilum Perty, 1849 
 – Cinetozona Olmo, Tellez, & Esteban, 1998 
 – Platynematum Foissner, Berger, & Kohmann, 
 – Pseudocinetochilum Obolkina, 1995 
 – Pseudoplatynematum Bock, 1952 
 – Sathrophilus Corliss, 1960 
 – Sphenostomella Jankowski, 1980 
 Family COHNILEMBIDAE Kahl, 1933 
 (for Lembidae) 
 Size, medium; shape, slender, finger-shaped, 
tapering to point anteriorly ; free-swimming; 
somatic ciliation, holotrichous, with one or more 
long caudal cilia; oral region extending along 
tapered anterior, with oral polykinetid 1, very 
long relative to the other two oral polykinetids 
and with dense dikinetids of kinety n along-
side it, forming a conspicuous, false “dou-
ble-membrane” ; scutica, composed of several 
kinetosomes in a triangular arrangement with some 
17.3 The Ciliate Taxa to Genus 415
trailing posteriorly as a file in the director merid-
ian, providing the origin of kinetsomes for all oral 
polykinetids; macronucleus, globular to ellipsoid 
to ribbon-like; micronucleus, present; contractile 
vacuole, present; cytoproct, present; bacterivorous; 
in marine and saline terrestrial habitats, including 
Great Salt Lake; one genus. 
 – Cohnilembus Kahl, 1933 
 Family CRYPTOCHILIDAE Berger in Corliss, 
 Size, medium to large; shape, usually laterally 
compressed and tapered, anteriorly and posteri-
orly, commonly with caudal projection bearing 
one or more longer cilia ; free-swimming; somatic 
ciliation, holotrichous, dense; oral region, usually 
posterior to equator with oral polykinetid 2 
relatively well developed ; macronucleus, globu-
lar to ellipsoid; micronucleus, present; contractile 
vacuole, present; cytoproct, present; bacterivorous; 
in marine habitats as endocommensals in the intes-
tines of sea urchins , and a few species in wood-bor-
ing molluscs ; nine genera. 
 – Biggaria Aescht, 2001 
 – Biggariella Profant in Corliss, 1979 [nomen 
 – Cryptochilum Maupas, 1883 
 – Metoikos Berger & Thompson in Corliss, 1979 
[nomen nudum] 
 – Tanystomium Berger in Corliss, 1979 [nomen 
 – Thigmozoon Santhakumari & Nair, 1973 
 – Velistoma Jankowski, 1980 
 – Yagiua Profant in Corliss, 1979 [nomen 
 Family ENTODISCIDAE Jankowski, 1973 
 Size, medium; shape, ovoid, laterally flattened 
(= disc-like), with narrow, truncated anterior 
end and, in some species, with small caudal pro-
jection bearing single caudal cilium ; free-swim-
ming; somatic ciliation, holotrichous; oral region, 
anterior, inconspicuous, with oral polykinetid 1 
smaller than other two oral polykinetids; macronu-
cleus, globular to ellipsoid; micronucleus, present; 
contractile vacuole, present; cytoproct, present; 
bacterivorous and detritivorous; in marine habitats 
as endocommensals in the intestines of sea urchins 
(Entodiscus ), in the mantle cavity of bivalve mol-
luscs ( Pectenita ) or in the esophagus of sipunculids 
(Cryptochilidium ); four genera. 
 – Cryptochilidium Schouteden, 1906 
 – Entodiscoides Song, Warren, & Wilbert, 1996 
 – Entodiscus Madsen, 1931 
 – Pectenita Jankowski, 1973 
 Family ENTORHIPIDIIDAE Madsen, 1931 
 Size, medium to large; shape, flattened laterally, 
with a prominent suture on the broad anterior 
end and with the posterior end tapered to tail ; 
somatic ciliation, holotrichous, dense, with single 
caudal cilium; oral region, an anterior, small, 
inconspicuous cavity, overhung by the frontal 
lobe of the body, containing a short paroral 
and three small oral polykinetids ; macronucleus, 
ellipsoid to elongate ellipsoid; micronucleus, may 
be multiple; contractile vacuole, present; cytoproct, 
present; bacterivorous and detritivorous; in marine 
habitats as endocommensals in the intestines of sea 
urchins ; one genus. 
 – Entorhipidium Lynch, 1929 
 Family LOXOCEPHALIDAE Jankowski, 1964 
 (syn. Cardiostomatellidae ) 
 Size, small to large; shape, elongate-ovoid, 
with naked apical end in some genera, and darkly-
appearing cytoplasm due to mineral inclusions; 
free-swimming; somatic ciliation, holotrichous; 
somatic kineties with pronounced parateny near 
anterior end, appearing as perizonal kineties 
especially to the right of the oral region ; caudal 
cilium, one or more; oral region, a small ante-
rior cavity, with rectangular oral polykinetids 
arranged in a Tetrahymena -like pattern, and a 
pronounced ribbed wall extending from a short 
paroral ; postoral suture, conspicuous, replacing 
the director-meridian in some species; in stoma-
togenesis, all oral polykinetids originating from 
scutica or scuticovestige; macronucleus, globular to 
ellipsoid, rarely as multiple nodules; micronucleus, 
may be multiple; contractile vacuole, present, often 
at level of macronucleus; cytoproct, present, large 
and band-like; microphagous, typically on bacte-
ria; in freshwater and occasionally brackish water 
416 17. The Ciliate Taxa Including Families and Genera
and terrestrial habitats, preferring polysaprobic or 
sapropelic environments; eight genera. 
 – Balanonema Kahl, 1931 
 – Cardiostomatella Corliss, 1960 
 – Dexiotricha Stokes, 1885 
 – Dexiotrichides Kahl, 1931 
 – Loxocephalus Eberhard, 1862 
 – Paradexiotricha Grolière, 1975 
 – Paraloxocephalus Small & Lynn, 1985 
 – Paratetrahymena Thompson, 1963 
 Family ORCHITOPHRYIDAE Cépède, 1910 
 (syn. Paranophryidae ) 
 Size, small to medium; shape, ovoid; free-
swimming; somatic ciliation, holotrichous; cau-
dal cilium, often present; oral region in anterior 
1/3–1/2 body; paroral c segment (= scuticoves-
tige) aligned along midventral postoral region ; 
macronucleus, globular to ellipsoid; micronu-
cleus, present; contractile vacuole, present; cyto-
proct, present; bacterivorous and histophagous; in 
marine habitats, especially significant as faculta-

Crie agora seu perfil grátis para visualizar sem restrições.