Grátis
102 pág.

Pré-visualização | Página 42 de 50
shallow depression; oral polykinetids reduced, with oral polykinetid 1 typically non-ciliated and with relatively inconspicuous oral ciliature on the other two oral polykinetids ; scutica, a trian- gular arrangement of ciliated kinetosomes in the director meridian ; macronucleus, globular to ellipsoid; micronucleus, present; contractile vacuole, present; cytoproct, present; bacterivorous; in marine, freshwater, and occasionally terrestrial habitats; seven genera. – Homalogastra Kahl, 1926 – Pseuduronema Hoare, 1927 – Urocyclon Song & Wilbert, 2000 – Uronema Dujardin, 1841 – Uronemella Song & Wilbert, 2002 * – Uronemopsis Kahl, 1931 – Uropedalium Kahl, 1928 Family UROZONIDAE Grolière, 1975 (syn. Urozonatidae ) Size, very small; shape, ovoid, but well rounded at anterior and posterior ends ; free-swimming; somatic ciliation as a series of short kineties, forming a single equatorial belt of somatic ciliature; caudal cilium, single, long; oral region as deep equatorial cavity with two oral polyki- netids of two rows of kinetosomes, transverse to the longitudinal axis of the oral region ; scu- tica of several kinetosomes in “V” configuration; macronucleus, globular; micronucleus, present; contractile vacuole, present; cytoproct, present; bacterivorous; in freshwater polysaprobic habitats; one genus. – Urozona Schewiakoff, 1889 Incertae sedis in Order Philasterida – Andreula Kahl, 1934 – Bizonula Corliss, 1960 – Cryptostomina Fedele, 1938 – Eurychilum André, 1910 – Lembadionella Kahl, 1933 – Ptyssostoma Hentschel, 1927 – Pusilloburius Corliss, 1979 – Rhinodisculus Mansfeld, 1923 – Sertumia Tucolesco, 1962 Order Pleuronematida Fauré-Fremiet in Corliss, 1956 (syns. Conchophthiriina p.p ., Deuterostomatina p.p ., Pleuronematorina ) Size, very small to medium, with occasional striking exceptions; shape, ovoid; free-swimming, but with some forms restricted to loricae; somatic ciliation, holotrichous, but often more sparse posteriorly, with thigmotactic ciliation often well developed in some taxa; caudal cilia, typically one or more, conspicuous in many species; extru- somes as somatic mucocysts, sometimes of two types, one being rod-like; oral region, often expansive, with paroral often prominent with long cilia, forming a curtain or velum as the organism feeds; paroral infraciliary base with a short a and an elongate b segment and with c segment as a permanent scutica or scuti- covestige; ribbed wall conspicuous, may be in two fields ; cytostome, equatorial or subequatorial in anterior 3/4 of body, rarely leaving room for a director-meridian; stomatogenesis of opisthe oral structures derived from paroral of proter and scutica ; microphagous, predominantly bacte- rivorous, but some species algivorous; in marine, freshwater, and terrestrial habitats, widely distrib- uted as free-living forms, sometimes in sands, but with some species commensalistic in molluscs and other invertebrates, and some species coprozoic; nine families. 17.3 The Ciliate Taxa to Genus 419 Family CALYPTOTRICHIDAE Small & Lynn, 1985 Size, small; shape, elongate ovoid; free-swim- ming, but residing in a tubular lorica ; somatic ciliation, holotrichous, dense; caudal cilium, present; oral region occupying most of ven- tral surface with conspicuous velum, extending around posterior of oral region and onto its left posterior margin, and with oral polykinetid 1 relatively longer and narrower than oral polyki- netid 2 ; cytostome, postequatorial; macronucleus, globular; micronucleus (?); contractile vacuole, present; cytoproct (?); bacterivorous; in brackish and freshwater habitats; one genus. – Calyptotricha Phillips, 1882 Family CONCHOPHTHIRIDAE Kahl in Doflein & Reichenow, 1929 (syn. Conchophthiriidae ) Size, small to medium; shape, generally ellipsoi- dal to broadly reniform, laterally compressed; free- swimming; somatic ciliation, holotrichous, dense; caudal cilia, may be present, sometimes long; thigmotactic ciliature on right anterior as field of structurally differentiated ciliated somatic dikinetids; oral region, nearly equatorial, as relatively small cavity into which vestibular kineties may extend on its right or left side; oral polykinetids reduced, obliquely oriented along left anterior wall of oral cavity; germinal row of stomatogenic kinetosomes deep in oral cavity ; macronucleus, globular to ellipsoid, rarely nodular; micronucleus, present; contractile vacuole, present; cytoproct, present; bacterivorous and detritivorous; in freshwater habitats as endocommensals in the mantle cavity (on gills) of bivalve molluscs ; two genera. – Conchophthirus Stein, 1861 – Conchoscutum Raabe, 1947 Family CTEDOCTEMATIDAE Small & Lynn, 1985 Size, small; shape, ovoid; free-swimming; somatic ciliation, holotrichous, sparse, typically of ciliated dikinetids; caudal cilia, prominent; oral region, midventral with cytostome posterior to equator; velum of paroral segments a , b , and c , comb-like, as an open “C”, not extending to the left of the cytostome ; ribbed wall, conspicuous ; oral polykinetid 3 at right angle to longitudinal axis of oral region ; macronucleus, globular to ellipsoid, rarely nodular; micronucleus, present; contractile vacuole, present; cytoproct, present; bacterivorous; in marine habitats; five genera. – Compsosomella Small & Lynn, 1985 – Ctedoctema Stokes, 1884 – Hippocomos Czapik & Jordan, 1977 – Paractedectema Small & Lynn, 1985 – Paractedoctema Song & Wilbert, 2000 Family CYCLIDIIDAE Ehrenberg, 1838 Size, very small to small; shape, ovoid to elongate- ovoid, often with glabrous anterior and posterior zones; free-swimming; somatic ciliation, hol- otrichous, sparse, but denser in the anterior half of the body in some genera; caudal cilium, distinctive, one to several ; oral region, not promi- nent, with cytostome variable in position and oral ciliature not conspicuous; paroral dikinetid, often inconspicuous, typically with its postcytostomal curve not extending anterior and left of cyto- stome ; oral polykinetids, often highly fragmented; macronucleus, globular to ellipsoid; micronucleus, large, often located in anterior third of body; contractile vacuole, present; cytoproct, present; bacterivorous; in marine, brackish, freshwater, and terrestrial habitats, widely distributed with intersti- tial, anaerobic, and coprozoic species; ten genera. – Apocyclidium Foissner, Agatha, & Berger, 2002 * – Caspionella Jankowski, 1980 – Cristigera Roux, 1899 – Cyclidium O.F. Müller, 1773 – Echinocyclidium Jankowski, 1980 – Isocyclidium Esteban, Finlay, & Embley, 1993 – Mesogymnus Berger in Corliss, 1979 [ nomen nudum ] – Paracyclidium Grolière, de Puytorac, & Grain, 1980 – Protocyclidium Alekperov, 1993 – Pseudocyclidium Small & Lynn, 1985 Family DRAGESCOIDAE Jankowski, 1980 Size, small; shape, ovoid, flattened; free- swimming; somatic ciliation, uneven, with 420 17. The Ciliate Taxa Including Families and Genera several close-set thigmotactic kineties along right-ventral anterolateral margin; oral region, midventral, with single oral polykinetid, which runs adjacent to the inside curve of the paroral and which is presumably a fusion of three oral polykinetids ; macronucleus, ellipsoid; micronu- cleus, present; contractile vacuole, present; cyto- proct, present; bacterivorous(?); in marine habitats as ectosymbionts on certain strongylocentrid echi- noids ; one genus. – Dragescoa Jankowski, 1974 Family HISTIOBALANTIIDAE de Puytorac & Corliss in Corliss, 1979 (syns. Sulciferiidae , Sulcigeridae ) Size, medium to large; shape, elliptical in out- line, with right side slightly concave and anterior end a little narrower than posterior; free-swim- ming; somatic ciliation, holotrichous,