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µm; free-swimming or sessile; pellicular 
alveoli; with simple or compound cilia in at least 
one stage of the life cycle ; complex cortical infra-
ciliature, divided into somatic and oral regions; cor-
tical micro tubular or microfibrillar structures 
associated with the kinetosome including a later-
ally- or anteriorly-directed kinetodesmal fibril at 
kineto somal triplets 5–7, a tangential or radial 
transverse microtubular ribbon at triplets 3–5, 
and a postciliary microtubular ribbon at triplet 
9 ; parasomal sac often adjacent to the base of the 
somatic cilium; extrusomes, common, with somatic 
extrusomes as mucocysts and oral extrusomes as 
toxicysts; oral region, generally monostomic, but 
some groups mouthless or polystomic; stomatogen-
esis, apokinetal, parakinetal, buccokinetal or teloki-
netal; fission homothetogenic and often perkinetal, 
isotomic or anisotomic, and occasionally multiple; 
nuclear dualism with one or more presumed 
diploid micronuclei and one to several amplip-
loid (rarely diploid or oligoploid) macronuclei , 
with acentric mitosis; sexual reproduction by 
conjugation, which may be temporary or total, 
with gametic nuclei formed by meiotic division 
of micronucleus ; contractile vacuole, typically 
present; cytoproct, often present; typically hetero-
trophic, feeding modes ranging from osmotrophy 
to phagotrophy, and some mixotrophy; broadly dis-
tributed in diverse aquatic and terrestrial habitats; 
ecto- or endosymbionts common; two subphyla. 
 Subphylum POSTCILIODESMATOPHORA 
Gerassimova & Seravin, 1976 
 (syns. Ciliostomatophora p.p ., Heterotricha 
+ Kinetofragminophora p.p ., Homotricha p.p ., 
 Polyhymenophora p.p ., Tubulicorticata p.p .) 
 Size, generally large; shape, typically elongate, 
highly contractile; sessile and free-swimming; cor-
tical alveoli, poorly developed; somatic ciliation 
with dikinetids that have postciliodesmata, a 
special arrangement of overlapping postciliary 
microtubular ribbons ; parasomal sacs, absent; 
somatic extrusomes as mucocysts, rhabdocysts, 
and/or pigmentocysts; oral structures, highly vari-
able, from prostomatous to a highly differentiated 
adoral zone of polykinetids; during stomatogen-
esis, the oral apparatus of the proter usually under-
going regression and redevelopment prior to and/or 
during cytokinesis; fission almost always isotomic; 
conjugation, temporary and isogamontic; diverse 
feeding habits; species widely distributed; rarely 
symbiotic; two classes. 
 Class KARYORELICTEA Corliss, 1974 
 (syns. Antostomatina p.p ., Epitrichina , Infero-
trichina , Karyorelictida , Karyorelictina , Loxodina , 
 Primociliatida - Karyorelictina , Rhynchophorina ) 
 Size, generally, large; shape, long, vermiform, 
fragile, flattened, often contractile; free-swimming 
and highly thigmotactic; many genera having a 
more-or-less conspicuous non-ciliated or sparsely 
ciliated surface region (= glabrous zone or stripe), 
and all taxa having a bristle-kinety surrounding 
the glabrous zone; somatic kinetids with post-
ciliodesmata whose major microtubular ribbons 
are typically separated by one microtubule ; sto-
matogenesis, parakinetal or buccokinetal; macro-
nuclei, non-dividing, two to many, containing 
approximately, sometimes slightly more than, 
the diploid amount of DNA; macronuclei form 
only by division of micronuclei, then differenti-
ate ; conjugation, temporary; contractile vacuole, 
often apparently absent; in marine and freshwater 
habitats, typically interstitial forms of marine 
sands; three orders. 
NOTE : Foissner (1995a), and see also Foissner 
and Dragesco (1996b), placed the Family 
 KENTROPHORIDAE in the Order Loxodida , 
whose members he defined as having a specialized 
dorsolateral ‘bristle’ kinety and an epipellicular 
mucus and/or scale layer on the left body surface. 
However, members of the Family LOXODIDAE 
do not have the scale layer, while some members 
of the Family TRACHELOCERCIDAE show a 
‘bristle-like’ kinety. Molecular genetic data should 
342 17. The Ciliate Taxa Including Families and Genera
demonstrate the phylogenetic affinity of the ken-
trophorids and help to demonstrate which morpho-
logical features are ancestral and which derived. 
 Order Protostomatida Small & Lynn, 1985 
 (syns. Kentrophorida p.p ., Symbiophagina p.p ., 
 Thysanophorida p.p ., Trachelocercida , Trachelo-
cercina ) 
 Shape, long to very long, highly contractile; 
ventral (= right?) somatic surface densely cili-
ated, dorsal (= left?) somatic surface glabrous 
(= non-ciliated) and of varying width; border 
between somatic surfaces ringed by a ‘bristle’ or 
‘bristle-like’ kinety that may extend from the left 
margin around the posterior end and anteriorly 
along the right margin, possibly with circumoral 
kinetids inserted in the anterior right region ; 
oral region, apical or ventral; in marine or estuarine 
interstitial habitats; two families. 
 Family KENTROPHORIDAE Jankowski, 1980 
 Size, large; shape, flattened, vermiform, often 
C-shaped in cross-section; free-swimming; ventral 
(= right?) surface densely ciliated, covered by kine-
ties of ciliated dikinetids; dorsal (= left?) surface 
only bordered by ‘bristle’ kinety and covered 
by mucous material colonized by symbiotic sul-
phur bacteria ; extrusomes as somatic secretory 
ampullae (= mucocysts?); oral region, apical, and 
oral ciliature, if present, highly reduced to rem-
nants of kinetids; cytostome, not permanent; nuclei 
in clusters, typically more than 10, commonly with 
four macro nuclei surrounding one micronucleus; 
contractile vacuole (?); cytoproct (?); feeding pri-
marily by ingesting ‘its’ symbiotic bacteria through 
the naked ventral surface; in marine interstitial 
habitats; one genus. 
 – Kentrophoros Sauerbrey, 1928 
 Family TRACHELOCERCIDAE Kent, 1881 
 (syn. Prototrachelocercidae , Sultanophryidae ) 
 Size, large; shape, elongate, contractile, often 
with distinct ‘head and neck’; free-swimming; 
somatic ciliature as files of dikinetids, which 
may cover the body completely or leave a gla-
brous longitudinal zone of varying width on the 
dorsal (= left?) side; glabrous zone, if present, 
bordered by a ‘bristle-like’ kinety; extrusomes 
as small somatic mucocysts; oral area apical, 
surrounded by circumoral ciliature of diki-
netids and accompanied by a brosse of either 
short ciliated rows or an unstructured ciliated 
tuft; cytostome, inconspicuous, not perma-
nent ; nuclei in one or more clusters, with several 
macronuclei surrounding one or two micro-
nuclei; contractile vacuole, absent; cytoproct 
(?); feeding on bacteria and smaller protists; in 
marine interstitial habitats; six genera. 
 – Kovalevaia Foissner, 1997 
 – Prototrachelocerca Foissner, 1996 
 – Sultanophrys Foissner & Al-Rasheid, 1999 
 – Trachelocerca Ehrenberg, 1840 
 – Trachelolophos Foissner & Dragesco, 1996 
 – Tracheloraphis Dragesco, 1960 
 Order Loxodida Jankowski, 1980 
 (syns. Cryptopharyngina , Loxodina ) 
 Size, medium to large; shape, laterally flat-
tened, non-contractile ; free-swimming; somatic 
cilia as files of dikinetids mainly on the right 
surface with the left surface barren except for sin-
gle marginal (= ‘bristle’?) kinety; extrusomes as 
somatic cnidocyst-like organelles in some genera; 
oral region, subapical on the narrow ventral 
surface; oral kinetids as dikinetids surrounding 
the oral area as two perioral kineties and one 
intraoral (= intrabuccal) kinety ; stomatogenesis, 
monoparakinetal or buccokinetal; nuclei in clus-
ters, typically of two macronuclei and one micro-
nucleus; in marine and freshwater (only Loxodes ) 
habitats, typically in anoxic sediments and anoxic 
water columns; two families. 
 Family CRYPTOPHARYNGIDAE Jankowski, 
1980
 Size, small to medium; shape, ovoid, flat, 
margin often serrate; epipellicular ornamen-
tal scales embedded in mucous layer on left 
body surface ; free-swimming; somatic ciliature 
as files

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