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 (syns. Apohymenida p.p ., Dishymenida p.p ., 
 Tetrahymenina , Tetrahymenorina ) 
424 17. The Ciliate Taxa Including Families and Genera
 Size, small to medium; shape, typically ovoid; 
somatic ciliation, holotrichous, with the first ante-
rior somatic kinetid in each kinety as a dikinetid; 
oral region, inconspicuous, except in species that 
undergo microstome-to-macrostome transforma-
tion; oral structures with right oral b segment 
of paroral (haplokinety, undulating membrane) 
and three left oral polykinetids (membranelles) 
in oral cavity ; stomatogenesis, monoparaki-
netal, typically involving the rightmost postoral 
somatic kinety ; microphagous forms, primarily 
bacterivorous, but some histophagous and several 
polymorphic forms with carnivorous macrostome 
stage; complex life cycle in histophagous and 
parasitic species; in freshwater habitats, sometimes 
terrestrial, and others as facultative or obligate 
parasites associated mainly with invertebrate hosts, 
but occasionally also vertebrate hosts, often fishes 
but one report from a mammal; five families with 
one family incertae sedis . 
 Family CURIMOSTOMATIDAE Jankowski, 1968 
 (syn. Curinostomatidae ) 
 Size, small; shape, pyriform to ovoid; free-swim-
ming; somatic ciliation, holotrichous, with the 
silverline system similar to that of Tetrahymena
(Family Tetrahymenidae) ; oral region, absent, 
hence astomatous ; macronucleus, globular; micro-
nucleus, present; contractile vacuole, present; cyto-
proct, present; osmotrophic (?); in freshwater and 
terrestrial habitats as obligate parasites of mol-
luscs and turbellarians ; two genera. 
NOTE : Rasmussen and Orias (1975) have 
described an astomatous mutant of Tetrahymena 
thermophila . It is entirely possible that the genera 
in this family represent such “natural” mutants, and 
thus should not be separated at this level from gen-
era in the Family Tetrahymenidae . Gene sequence 
data should easily test this hypothesis. 
 – Curimostoma Kozloff, 1954 
 – Dogielella Poljansky, 1925 
 Family GLAUCOMIDAE Corliss, 1971 
 (syns. Bromeliophryidae , Bursostom[at]idae , Espe-
joiidae , Frontoniidae p.p ., Tetrahymenidae p.p .) 
 Size, small to medium; shape, ovoid to ellipsoid; 
free-swimming; somatic ciliation, holotrichous, 
with right ventral kineties curving left, but rarely 
twisting abruptly anteriorly to run parallel to 
the anterior suture (except in Glaucomella ) ; oral
cavity, relatively large, with at least posterior 
portion of paroral, non-ciliated, and completely 
resorbed in Bursostoma , and with either or both 
oral polykinetids 2 and 3 having >3 kinetosomal 
rows ; a small group of kinetosomes, the so-called 
X group, typically anterior to the enlarged oral 
polykinetid 2 ; macronucleus, globular to ellipsoid, 
sometimes reniform; micronucleus, present; con-
tractile vacuole, present; cytoproct, present; micro-
phagous, but several species carnivorous on other 
ciliates, with some undergoing a microstome-to-
macrostome transformation to become carnivores; 
resting cysts in some species; in freshwater, and 
occasionally terrestrial, habitats; 12 genera and 
three genera incertae sedis . 
 – Bromeliophrya Foissner, 2003 *
 – Bursostoma Vörösváry, 1950 
 – Chasmatostoma Engelmann, 1862 (subj. syn. 
Colpoda ) 
 – Dapedophrya Foissner, 1995 
 – Dichilum Schewiakoff, 1893 
 – Epenardia Corliss, 1971 
 – Espejoia Bürger, 1908 
 – Glaucoma Ehrenberg, 1830 
 – Glaucomella Grolière, 1977 
 – Jaocorlissia Small & Lynn, 1985 
 – Monochilum Schewiakoff, 1893 
 – Physalophrya Kahl, 1931 
Incertae sedis in the Family Glaucomidae 
 – Discozoon Vuxanovici, 1960 
 – Pinchatia Shibuya, 1931 
 – Pleurochilidium Stein, 1860 
 Family SPIROZONIDAE Kahl, 1926 
 Size, small; shape, elongate ovoid; free-swim-
ming; somatic ciliation, holotrichous, with 
somatic kineties on left side and dorsal left 
twisting slightly; caudal cilia, forming a poste-
rior ring ; oral structures with paraoral having 
isolated dikinetids at its anterior end (= an a
segment?) and oral polykinetid 1 with its first 
kinetosomal row as long as oral polykinetid 
2, but its kinetosomal rows 2 and 3 shorter ; 
macronucleus, globular to ellipsoid; micronucleus, 
present; contractile vacuole, present; cytoproct (?); 
17.3 The Ciliate Taxa to Genus 425
feeding on bacteria, flagellates, and microalgae; 
in freshwater saprobic habitats, very rare; two 
 – Spirozona Kahl, 1926 
 – Stegochilum Schewiakoff, 1893 
 Family TETRAHYMENIDAE Corliss, 1952 
 (syns. Deltopylidae , Frontoniidae p.p ., Leuco-
phry[i]dae ) 
 Size, small; shape, pyriform to elongate-ovoid to 
cylindrical; free-swimming; somatic ciliation, hol-
otrichous, with one and up to nine postoral kineties; 
caudal cilium in some species; oral structures with 
paroral dikinetid ciliated along its entire length, 
not covered by pellicular structures, and three 
oral polykinetids, each of equal number of rows 
of kinetosomes, although not always of the same 
length ; macronucleus, globular to ellipsoid to rib-
bon-like, rarely nodular; micronucleus, present, but 
some amicronucleate “species” recognized; con-
tractile vacuole, present; cytoproct, present; bac-
terivorous, but with some species of Tetrahymena
exhibiting microstome-to-macrostome transforma-
tion; cysts, both resting and reproductive, in some 
species; in freshwater or terrestrial habitats as free-
living forms, but others as facultative and obligate 
parasites in variety of hosts, such as slugs , snails , 
 clams , enchytraeid worms , midges , mosquitoes , 
 tadpoles , and fishes , and one species found in the 
urinary tract of a dog ; four genera. 
NOTE : Foissner, Strüder-Kypke, van der Staay, 
Moon-van der Staay, & Hackstein (2003) have 
described some unusual tetrahymenids from bro-
meliad “tanks” and assigned these to the genus 
Lambornella and suggest that there may be several 
other undescribed genera. However, these all group 
well within the clade of the genus Tetrahymena
using the small subunit rRNA gene sequences. 
Thus, it is likely that Lambornella and these other 
“undescribed genera” can be considered junior 
synonyms of the genus Tetrahymena . What they 
represent is the developmental plasticity of the 
oral features of this clade as has been demon-
strated by investigations of developmental mutants 
of Tetrahymena (Frankel, 1991 and references 
 – Deltopylum Fauré-Fremiet & Mugard, 1946 
 – Lambornella Keilin, 1921 
 – Paraglaucoma Kahl, 1926 
 – Tetrahymena Furgason, 1940 
 Family TURANIELLIDAE Didier, 1971 
 Size, small to large; shape, elongate-ovoid, 
sometimes tapering posteriorly; free-swimming; 
somatic ciliation, holotrichous, with right ven-
tral kineties curving left, twisting anterior of the 
oral region, sometimes abruptly, to run paral-
lel to the anterior suture ; one or more somatic 
kineties interrupted by left edge of oral cavity ; 
oral structures, in anterior half of cell, with 
paroral dikinetid, whose anterior part is ciliated 
and whose posterior part is of non-ciliated kine-
tosomes lying beneath finger-like extensions of 
the ribbed wall pellicle, and three elongate oral 
polykinetids ; macronucleus, globular to elongate 
ellipsoid; micronucleus, present; contractile vacu-
ole, present; cytoproct, present; bacterivorous, but 
with dimorphic life cycle in Turaniella , which has 
a macrostome form carnivorous on other ciliates; in 
freshwater habitats; four genera. 
 – Colpidium Stein, 1860 
 – Dexiostoma Jankowski, 1967 
 – Paracolpidium Ganner & Foissner, 1989 
 – Turaniella Corliss, 1960 
Incertae sedis in Order Tetrahymenida 
 Family TRICHOSPIRIDAE Kahl, 1926 
 Size, small; shape, ovoid; free-swimming; 
somatic ciliation, holotrichous, except for a 
special band of cilia associated with a pellicular 
ridge that spirals dextrally posteriorly, end-
ing in a transverse ring of cilia;

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