Grátis
102 pág.

Pré-visualização | Página 25 de 50
in character- istic helical coils so that the margin of the cone spirals at least twice around the central column, but may spiral up to a half a dozen full turns in some species ; no spines; collar, short, broad; cili- ation with posterior part of the right field covering the spiralling cone and the left field at the base of the cone; sessile; peduncle, low and broad; macro- nucleus, heteromerous, ellipsoid; micronucleus, present; contractile vacuole, possibly present; cyto- proct, present; feeding (?); typically in freshwater habitats, usually on the gills of gammarid amphi- pods ; three genera. – Cavichona Jankowski, 1973 – Serpentichona Jankowski, 1973 – Spirochona Stein, 1852 Order Cryptogemmida Jankowski, 1975 (syns. Endogemmina , Dorsofragmina + Ventro- fragmina ) Size, small; shape, often flattened, leaf-like, and angular; spines common and of several types; collar, reduced; stalk, typically present, of vary- ing length; internal budding, with up to eight tomites produced in a crypt or marsupium; macronucleus, heteromerous, with orthomere directed antapically away from funnel ; in marine habitats, occurring solely on littoral and open ocean crustaceans (i.e. amphipods , copepods , cya- mids , nebaliids ), including crustacean epibionts of whales ; six families. Family ACTINICHONIDAE Jankowski, 1973 Size, small to medium; shape, sac-like, usually flattened; cortex, often thickened; apical end coni- cal, not flattened, sometimes with a fold, and with conspicuous spines in some species; cone rotated 90° to right, relative to body and point of attachment ; collar may be elongate; ciliation with left field considerably reduced; sessile; peduncle, present, rather than stalk, with broad part of body often closely applied to substrate; crypt of vary- ing size; macronucleus, heteromerous, ellipsoid; micronucleus, present; contractile vacuole, absent; cytoproct, absent; feeding (?); in marine habitats, exclusively on nebaliids ; six genera. – Actinichona Jankowski, 1973 – Carinichona Jankowski, 1973 – Crassichona Jankowski, 1973 – Cristichona Jankowski, 1973 – Kentrochonopsis Doflein, 1897 – Rhizochona Jankowski, 1973 Family ECHINICHONIDAE Jankowski, 1973 Size, small to medium; shape, rhombic or spin- dle-like, markedly flattened dorsoventrally; cone flattened, not rotated; cone with smooth wall and small teeth on its margins ; collar distinct, nar- row, low; ciliation with long and narrow right field and very reduced left field ; sessile; stalk, quite long in some species; crypt, very deep and broad ; macronucleus, heteromerous, ellipsoid; micronucleus, present; contractile vacuole, absent; cytoproct, absent; feeding (?); in marine habitats, on nebaliids ; three genera. – Coronochona Jankowski, 1973 – Echinichona Jankowski, 1973 – Eurychona Jankowski, 1973 Family INVERSOCHONIDAE Jankowski, 1973 (syn. Pleochonidae ) Size, small to medium; shape, sometimes elon- gate, flattened dorsoventrally; very heavy, well- developed body spines in some species; apical end very broad, flattened, usually simple, but occasionally with a few spines ; cone flattened, not rotated; collar, distinct; ciliation with left field larger than right field, which may be subdivided into two components ; sessile; peduncle, exceed- ingly short; crypt relatively shallow ; macro- nucleus, heteromerous, elongate; micronucleus, present; contractile vacuole, absent; cytoproct, absent; feeding (?); in marine habitats, on nebali- ids ; five genera. – Ceratochona Jankowski, 1973 – Chonosaurus Jankowski, 1973 – Inversochona Jankowski, 1973 – Kentrochona Rompel, 1894 – Pleochona Jankowski, 1973 Family ISOCHONIDAE Jankowski, 1973 Size, medium; shape, cylindrical, elongate, not flattened; cone, rounded, simple, funnel-shaped, rather small and undistinguished, and in line 386 17. The Ciliate Taxa Including Families and Genera with main axis of long body ; collar, short; cili- ation with right field not subdivided and left field relatively large; sessile; stalk, sometimes long; crypt of moderate size; macronucleus, heteromer- ous, ellipsoid; micronucleus, present; contractile vacuole, absent; cytoproct, absent; feeding (?); in marine habitats, with very wide distribution on appendages or shell of amphipods , nebaliids , and cyamids , including the “ whale-lice ” found on species of several genera of whales from various oceans; five genera – Cyamichona Jankowski, 1971 – Inermichona Jankowski, 1971 – Isochona Jankowski, 1973 – Thalassochona Jankowski, 1971 – Trichochona Mohr, 1948 Family ISOCHONOPSIDAE Batisse & Crumeyrolle, 1988 Size, small to medium; shape, cylindrical, elon- gate; cone, rounded, funnel-shaped, in line with main axis of long body; cone margin indented by flexible folds that are able to close the opening to the oral region ; collar, short; ciliation with left field and a right field, which is subdivided into an horizontal upper band and an oblique lower band; sessile; peduncle, short; macronucleus, heteromer- ous, ellipsoid; micronucleus, present; contractile vacuole, absent; cytoproct, connected by tube to the cell surface; feeding (?); in marine habitats, on the periopods of copepods ; one genus. – Isochonopsis Batisse & Crumeyrolle, 1988 Family STYLOCHONIDAE Mohr, 1948 Size, small to medium; shape, triangular or rhomboid, leaf-like, markedly flattened dorsoven- trally, spines, may be large, elongate or may be as rows of papillae; cone, flattened, not rotated; conal margin often spiny, with pockets and folds in conal wall ; collar, very short; ciliation with larger right field and a left field that may be reduced to an almost vertical band; sessile; stalk, of varying length, sometimes unusually long; crypt, often very deep ; macronucleus, heteromerous, ellipsoid; micronucleus, present; contractile vacuole, absent; cytoproct, absent; feeding (?); in marine habitats, on nebaliids; ten genera. – Armichona Jankowski, 1973 – Ctenochona Jankowski, 1973 – Dentichona Jankowski, 1973 – Eriochona Jankowski, 1973 – Flectichona Jankowski, 1973 – Oxychonina Corliss, 1979 – Paraoxychona Jankowski, 1973 – Pterochona Jankowski, 1973 – Spinichona Jankowski, 1973 – Stylochona Kent, 1881 Subclass Rhynchodia Chatton & Lwoff, 1939 (syns. Rhynchodea p.p ., Toxistomia p.p .) Size, small to rarely medium; shape, ovoid, somewhat flattened, typically with pointed ante- rior end; free-swimming, but if parasitic, typically attached to host tissue; adult forms, either devoid of somatic ciliature or with it mostly restricted to an anteroventral thigmotactic field; oral region not bounded by oral kinetal structures; oral appa- ratus a suctorial tube supported only by phyl- lae ; oral extrusomes, as toxic (?) acmocysts or haptotrichocysts ; reproduction, isotomic fission or often by budding; larval forms typically with two ciliated fields; macronucleus, homomerous; micronucleus, often large, sometimes multiple; predators of other ciliates, especially suctorians and peritrichs, or parasitic (?) on gills or mouth- parts of diverse invertebrates in marine and fresh- water habitats, but most often on gills of marine bivalve molluscs ; two orders. NOTE : The classic monographs on this group are by Chatton and Lwoff (1949, 1950). Raabe (1970b) provided the last major taxonomic treat- ment. Order Hypocomatida Deroux, 1976 (syns. Hypocomatina , Hypocomida , Hypocomina + Macrostomatina ) Size, small; shape, dorsoventrally flattened; somatic kineties, essentially restricted to the ventral surface with a short anterio-lateral left kinety, a presumed homologue of the dorsal right kinetofragment of cyrtophorines; poste- rior adhesive region bounded by somatic kine- ties in right-ventral pit or fosette ; oral ciliature,