Morphology and infraciliature of two new marine ciliates, Paracyrtophoron tropicum nov. gen., nov. spec. and Aegyria rostellum nov. spec. (Ciliophora, Cyrtophorida), isolated from tropical waters in southern China

The morphology and infraciliature of two new marine cyrtophorid ciliates, Paracyrtophoron tropicum nov. gen., nov. spec. and Aegyria rostellum nov. spec., isolated from tropical waters in southern China, were investigated using live observation and protargol impregnation methods. Paracyrtophoron nov. gen. differs from the closely related Cyrtophoron by lack of fragment kinety at anterior ends of right somatic kineties and thigmotactic cilia in posterior portion of ventral surface, while from the well-defined Chlamydodon by lack of the cross-striped band around the periphery of the somatic field. Paracyrtophoron tropicum nov. spec., the type of the new genus, can be recognized by the combination of the following characters: cell size about 150-175×70-90μm in vivo; elliptical to kidney-shaped in outline, dorsoventrally flattened about 2.5:1; conspicuous cortical granules; one canal-like depression extending from postoral area to subcaudal region of cell; ca. 90 somatic kineties; 12-16 nematodesmal rods; one or two terminal fragments on dorsal side. Aegyria rostellum is characterized by the following features: size about 90-150×40-70μm in vivo, triangular or ear-shaped body with broad anterior end, having a rostriform structure and pigment spots, 56-63 somatic kineties, one preoral kinety, three or four circumoral kineties, and 32-42 nematodesmal rods. Based on previous and current studies, the definition for the genus Aegyria is updated: body dorsoventrally flattened; oral ciliature consisting of one preoral and several circumoral kineties; podite located in posterior ventral region and surrounded by somatic kineties; no obvious gap between right and left somatic kineties; postoral and left somatic kineties progressively shortened posteriorly from right to left. Additionally, two new combinations were proposed.     

Kyaroikeus cetarius N. G., N. Sp.: A Parasitic Ciliate from the Respiratory Tract of Odonticete Cetacea

ABSTRACT. Examination of mucus discharged from the blowholes of live odonticete Cetacea and material collected from nasal orifices of dead hosts routinely revealed infestations of a large spindle-shaped ciliate. Kyaroikeus cetarius n. g., n. sp. These ciliates had a prominent posterior podite and were holotrichously ciliated except for a conspicuous bipolar stripe extending along the left margin of the cell. Most specimens were free-swimming and moved slowly through freshly collected mucus, but some individuals were attached to host cells or cellular debris by a transparent thread secreted from the podite. The oral architecture of protargol-impregnated K. cetarius consisted of one preoral and two circumoral kinetics set within a deep oral cavity continuous with an extensive, posteriorly directed cytopharynx. Somatic kineties were composed entirely of monokinetids and formed an expansive right ciliary field covering most of the cell surface, a reduced left ciliary field adjacent to the oral cavity, and a group of four kinetal fragments located mid-ventrally within a shallow pocket. Subkinetal microtubules were associated with the kineties of the right and left fields, and the non-ciliated stripe was underlain by a series of longitudinal fibers. The ciliate's large, heteromeric macronucleus was centrally positioned and clearly evident in living or stained specimens, while the ellipsoid micronucleus was located adjacent to the cytopharynx and often inconspicuous. K. cetarius has several morphological attributes typical of phyllopharyngian ciliates (e.g., adhesive organelle, heteromeric macronucleus, somatic kineties of monokinetids, subkinetal microtubules), and, except for its nearly holotrichous ciliation, most closely resembles dysteriine ciliates.     

The apertospathulidae, a new family of haptorid ciliates (protozoa, ciliophora)

We studied the morphology of three rare haptorid ciliates, using live observation and silver impregnation: Apertospathula verruculifera n. sp., Longispatha elegans n. gen., n. sp., and Rhinothrix porculus (Penard, 1922) n. gen., n. comb. Simple ethanol fixation (50-70%, v/v) is recommended to reveal the ciliary pattern of "difficult" ciliates, such as R. porculus, by protargol impregnation. The three genera investigated have a distinct feature in common, viz., a lasso-shaped oral bulge and circumoral kinety, where the right half is slightly to distinctly longer than the left and the circumoral kinety is open ventrally. Thus, they are united in a new spathidiid family, the Apertospathulidae n. fam., which probably evolved from a Bryophyllum-like ancestor by partial reduction of the oral bulge and circumoral kinety. Apertospathula verruculifera has a wart-like process, the palpus dorsalis, at the anterior end of the dorsal brush. The right branch of the circumoral kinety is only slightly longer than the left one. Longispatha elegans has a straight oral bulge and circumoral kinety, the right branch of which extends to the posterior end of the body while the left branch ends in the anterior third of the body. Rhinothrix porculus, a curious ciliate with a snout-like dorsal elongation of the oral bulge, the palpus oralis, has a highly characteristic ciliary pattern: the oral pattern is as in Longispatha, but the bulge and circumoral kinety extend spirally to the posterior end of the body while the somatic kineties course meridionally. This is achieved by inserting some shortened kineties in the curves of the oral bulge.     

Updating the Trachelocercids (Ciliophora, Karyorelictea). I. A Detailed Description of the Infraciliature of Trachelolophos gigas N. G., N. Sp. and T. filum (Dragesco & Dragesco-Kernéis, 1986) N. Comb

ABSTRACT. Trachelolophos gigas n. g., n. sp. and T. filum (Dragesco & Dragesco-Kernéis, 1986) n. comb. (basionym: Tracheloraphis filum) were discovered in the mesopsammon of the French Atlantic coast at Roscoff. Their morphology and infraciliature were studied in live and protargol impregnated specimens. The new genus, Trachelolophos, belongs to the family Trachelocercidae and is unique in having a conspicuous ciliary tuft, which is very likely a highly modified brosse, in the oral cavity. The two species investigated have a very similar infraciliature, differing only in morphometric characteristics and in the nuclear configuration. The entire somatic and oral infraciliature consists of dikinetids which have both basal bodies ciliated or only the anterior or posterior ones, depending on the region of the cell. The right side is densely and uniformly ciliated. Its kineties extend onto the left side to the glabrous stripe, where an anterior and posterior secant system are formed, reducing the number of kineties in the narrowed neck and tail region. The left side bears a narrow glabrous stripe bordered by slightly irregularly arranged dikinetids having rather stiff cilia (bristles), possibly forming an uninterrupted, prolate ellipsoidal (bristle) kinety as indicated by their ciliation. The bristle kinety commences subapically at the right margin of the glabrous stripe, extends posteriorly, then anteriorly at the left, to end up at the right margin again. The dikinetids of the right posterior portion of the bristle kinety have the posterior basal bodies ciliated, whereas the anterior basal bodies are ciliated in its left and right anterior portion. The ends of the bristle kinety meet distinctly subapically at the right margin of the glabrous stripe, as indicated by the diametrically opposed ciliation of the dikinetids. The anterior region (head) of the cell bears a distinct circumoral kinety composed of very regularly arranged dikinetids, associated with nematodesmata forming an oral basket together with the nematodesmal bundles originating from the oralized somatic dikinetids at the anterior end of the somatic kineties. The systematics of trachelocercid ciliates are briefly reviewed and discussed.     

Establishment of a new amphileptid genus, Apoamphileptus nov. gen. (Ciliophora, Litostomatea, Pleurostomatida), with description of a new marine species, Apoamphileptus robertsi nov. spec. from Qingdao, China

A new pleurostomatid genus Apoamphileptus is described, which is diagnosed as: Belonging to the Amphileptidae with spica on right side; on each side of the cell, a single perioral kinety, which encircles the cytostome and does not extend to the posterior end of the cell; somatic kineties of both sides near ventral margin shortened and forming a postoral suture; two to several extra fragments with densely arranged dikinetids located in anterior portion of left side. As the type species, the morphology and infraciliature of Apoamphileptus robertsi nov. spec., isolated from a shrimp-farming pond near Qingdao (Tsingtao), China, have been investigated using living observations and the protargol silver impregnation method. The diagnosis for this new species is: Apoamphileptus 90-180 x 30-60 microm in vivo, body elongate pyriform-shaped and slightly flattened; with one cross-striated band along the cytostome; 2-6 (generally 4) large macronuclear nodules, one micronucleus; 33-43 right somatic kineties; left side 6-8 kineties; two extra anterior fragments on left side; about 13 contractile vacuoles dispersed throughout whole body; extrusomes absent or not recognizable; marine habitat. Some morphologically related morphotypes are discussed and tabulated. Regarding the pattern of infraciliature and other morphological features, the well-described fresh-water species, Amphileptus claparedii Stein, 1867 is believed to be a member of this new genus, hence a new combination is suggested: Apoamphileptus claparedii (Stein, 1867) nov. comb.     

Pelagostrobilidium liui n. sp. (Ciliophora,Choreotrichida) from the Coastal Waters of Northeastern Taiwan and an Improved Description of Pelagostrobilidium minutum Liu et al., 2012

The number of somatic kineties in Pelagostrobilidium ranges from 4 to 6 according to the present state of knowledge. This study investigates Pelagostrobilidium liui n. sp. using live observation, protargol stain, and small subunit rDNA data sequencing. Pelagostrobilidium liui n. sp. is characterized by having a spherical‐shaped body, four somatic kineties, with kinety 2 spiraled around the left side of body, about six elongated external membranelles, and invariably no buccal membranelle. It differs from its most similar congener, Pelagostrobilidium minutum Liu et al., 2012 , in (i) cell shape; (ii) macronucleus width; (iii) oral apparatus; (iv) anterior orientation of kinety 2; (v) location where kinety 2 commences; (vi) arrangement of kinety 1; (vii) distance between the anterior cell end and the locations where kineties commence; and (viii) the presence of 12 different bases (including two deletions) in the small subunit rDNA sequences. The diagnosis of P. minutum Liu et al., 2012 is also improved to include the following new characteristics: invariably four somatic kineties; kineties 2 and 4 alone commence at the same level; kinety 2 originates from right anterior cell half on ventral side, extends sinistrally posteriorly, over kinety 1, around left posterior region, terminates near posterior cell end on dorsal side; kinety 1 commences below anterior third of kinety 2.     

Taxonomy of five species of cyrtophorids (Protozoa: Ciliophora) including consideration of the phylogeny of two new genera

Cyrtophorids are a specialized group of ciliated protozoa with multitudinous morphotypes. In the present work, the morphology and infraciliature of two new and three rarely known species, including two new genera of cyrtophorid ciliates, Heterohartmannula fangi gen. et sp. nov. , Aporthotrochilia pulex (Deroux, 1976) gen. et comb. nov. , Trochilia alveolata sp. nov. , Trochochilodon flavus Deroux, 1976, and Hypocoma acinetarum Collin, 1907, are described. Heterohartmannula gen. nov. is mainly characterized by a combination of features: two circumoral kineties obliquely arranged, podite not surrounded by somatic kineties, and no distinct gap between left and right ciliary field. Aporthotrochilia gen. nov. is diagnosed mainly by: podite present, oral ciliature reduced to two fragments, several kinety fragments positioned on the right posterior of frontoventral kineties and several terminal fragments. Phylogenetic analyses based on the small subunit rRNA (SSU rRNA) gene sequences support the establishment of two new genera and indicate that Heterohartmannula is most closely related to Hartmannula, and Aporthotrochilia is basal to the Cyrtophoria‐Chonotrichia clade. Trochilia alveolata sp. nov. differs from its congeners mainly by having a conspicuous alveolar layer. In addition, detailed live and infraciliature data of Hypocoma acinetarum and Trochochilodon flavus are supplied. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 1–17.     

New contributions to the Cyrtophoria ciliates (Protista,Ciliophora): Establishment of new taxa and phylogenetic analyses using two ribosomal genes

Periphytic ciliates play a vital role in the material cycle and energy flow of microbial food web, however, their taxonomy and biodiversity are inadequately studied given their high species richness. Two new and one little known species, viz. Derouxella lembodes gen. et sp. nov., Cyrtophoron multivacuolatum sp. nov., and Cyrtophoron apsheronica Aliev, 1991, collected from coastal waters of China, were investigated using modern methods. Derouxella gen. nov. can be recognized by having dorsoventrally flattened body, a podite, one fragmented preoral kinety, two parallel circumoral kineties, and somatic kineties progressively shortened from right to left. Morphological classification and phylogenetic analyses based on nuclear small subunit ribosomal RNA (nSSU rRNA) and mitochondrial small subunit ribosomal RNA (mtSSU rRNA) gene sequence data inferred that Derouxella gen. nov. occupies an intermediate position between Hartmannulidae and Dysteriidae. Cyrtophoron multivacuolatum sp. nov. is characterized by large body size, the numbers of somatic kineties and nematodesmal rods, and having numerous contractile vacuoles. The genus Cyrtophoron and the poorly known species C. apsheronica were redefined. Even with the addition of newly obtained nSSU rRNA and mtSSU rRNA gene sequences of Cyrtophoron, the family Chlamydodontidae was still recovered as a monophyletic group, the monophyly of Cyrtophoron was supported too.     

钩刺斜管虫无性生殖期间的口纤毛器及细胞发生研究（原生动物：纤毛虫）

钩刺斜管虫口和体纤毛器演化模式是研究该类动物个体发生的优秀模型。通过跟踪研究,澄清了后仔虫口器发生以及体纤毛器起源上的几点疑问,并证实：体左侧二列片段动基列为同源再造而非来自老结构的分裂或复制;三列围口纤毛均为双动基列构造;后仔虫口原基场的构建系由５列体动基列共同参与完成的,其中最左侧两列短的原基片段与原基１整合为一体,从而发展成营养期虫体的外围口动基列;后仔虫背触毛原基为独立发生。     

Dexiotrichides pangi n. sp. (protozoa,ciliophora, scuticociliatia), a new marine ciliate from the north China sea

The morphology, infraciliature, and silverline system of a new marine scuticociliate, Dexiotrichides pangi n. sp. were investigated. The new species is characterized by: size about 45-65 x 20-25 microm in vivo with kidney-like body shape and obliquely truncated semicircle-shaped apical plate; cytostome at bottom of conspicuously depressed oral cavity, which is located at the cell equatorial level; paroral membrane extending anteriorly to membranelle 3; scutica multi-rowed; 33-38 somatic kineties; contractile vacuole near ventral side and subcaudally positioned, opening at posterior end of somatic kinety 3; one oval macronucleus and one small micronucleus; caudal cilium positioned in a small pouch; marine habitat. Based on the data obtained, an improved diagnosis for the genus Dexiotrichides is suggested: body with circular cross-section and conspicuous cilia-free apical plate; buccal cavity conspicuously depressed with cytostome located near or at equatorial level; three membranelles transversely orientated each with 2-3 rows; paroral membrane zigzaging structure, extending to about half of the length of buccal field; multi-rowed scutica; somatic kinety one strongly shortened and terminating anteriorly at posterior end of buccal field; basal bodies in equatorial region arranged usually in circular pattern, while in the anterior portion of somatic kinety 2, basal bodies characteristically in pairs and separated from the posterior part of kinety 2; one caudal cilium.     

Two new entodiniomorphid Triplumaria ciliates from the intestine of the wild African white rhinoceros

Two new species of Triplumaria in the order Entodiniomorphida, T. alluvia n. sp. and T. grypoclunis n. sp., are described from the large intestine of the wild African white rhinoceros. T. alluvia has three bud-shaped caudalia, one broad skeletal plate with a wavy left dorsal edge, and an axe-shaped tail flap. T. grypoclunis has three short arched caudalia, two broad skeletal plates, and a pointed and ventrally curved tail flap. These two new species have a C-shaped adoral polybrachykinety, a slender perivestibular polybrachykinety, and paralabial kineties in their retractable adoral ciliary zone. In T. alluvia, the perivestibular polybrachykinety is joined to both ends of the adoral polybrachykinety and paralabial kineties along the ventral side of the adoral polybrachykinety, showing the same arrangement as in Cycloposthium species. In T. grypoclunis, the perivestibular polybrachykinety is joined only to the right end of the adoral polybrachykinety and paralabial kineties along the left ventral side of the adoral polybrachykinety, showing an arrangement analogous to the Tripalmaria species.     

Metacystis borrori n. sp. (Ciliophora: Metacystidae) on the seagrass Thalassia testudinum

A new epibiontic ciliate of the genus Metacystis is described on the seagrass Thalassia testudinum of the coral reef lagoons of Veracruz, Mexico. The ciliate was studied in living and stained specimens and under the scanning electron microscope. The cell body (10-35 x 10-18 microm in vivo) is transversely annulated (4-6 rings). The somatic ciliature consists of 22-30 longitudinal kineties, and patterned as 5-7 transverse kineties. The circumoral kinety is composed of kinetosomes closely spaced. The macronucleus diameter measures about 3-7 microm. The lorica (18-61 x 11-26 microm) has the posterior end round to conical or irregular with mucoid filaments. This prostomatid colonizes both natural and artificial substrates placed in an aquarium. Metacystis borrori n. sp. is a species that forms part of the ciliate community on Thalassia testudinum with a temperature range of 21-26 degrees C and a salinity of 32-40 per thousand.     

Microscopical observations on four marine Dysteria species (Ciliophora, Cyrtophorida)

Four interesting strains of marine ciliates belonging to the genus Dysteria, collected from the coastal area of Qingdao, China, were investigated using living observations and silver impregnation methods. New data are supplied in redefinitions of three poorly known species, all of which had two contractile vacuoles. D. crassipes Claparède and Lachmann, 1859 has a rectangular body about 65 x 35 microm in vivo, with a podite subcaudal on the ventral side and a dorsal spine on some specimens; it has four right kineties, the rightmost two of which extend dorso-apically; both plates of examined specimens had a covering of ectosymbiotic bacteria. D. semilunaris (Gourret and Roeser, 1886) Kahl, 1931 has an oval body about 30 x 16 microm in vivo, with a caudal podite and a groove on the left plate; it also has four right kineties, the rightmost two of which extend dorso-apically. D. pectinata (Nowlin, 1913) Kahl, 1931 also has an oval body and caudal podite, but is larger at about 85 x 40 microm in vivo; it has seven right kineties, the rightmost two of which extend dorso-apically and the leftmost one is short and posterior. The fourth strain was D. brasiliensis Faria et al., 1922, which was found to vary in both shape and the presence or absence of a dorsal spine, it also hosts numerous rod-shaped ectosymbiotic bacteria on both plates of the cell. Based on information available, a key to the marine species that have been investigated by silver impregnation is updated.     

Pelagostrobilidium wilberti n. sp. (Oligotrichea, Choreotrichida): morphology and morphogenesis

Morphology, infraciliature, morphogenetic features, and some ecological data for Pelagostrobilidium wilberti n. sp. are described. This new species was collected from a temporary pond in Magdalena, Buenos Aires province, Argentina, which was sampled monthly from August 2003 to July 2005. The species was found in autumn and winter. Observations were made in vivo and after staining with protargol. Pelagostrobilidium wilberti n. sp. measures 63-84 x 42-49 microm in vivo and is conical in shape, with a posterior spine-like cytoplasmic process. It possesses 6 somatic kineties, with kinety 2 sinistrally curved and shorter than the others. The oral apparatus is composed of 25-32 external and two internal membranelles. The macronucleus is horseshoe-shaped and located beneath the oral apparatus; two or three spherical micronuclei lie dorsally. There is a posterior contractile vacuole. Morphogenesis is hypo-apokinetal and begins dorsally between the curved kinety 2 and kinety 3. After the discovery of this new species, the diagnosis of the genus Pelagostrobilidium was amended.     

Cortical and Nuclear Events During Cell Division and Resting Cyst Formation in Colpoda inflata

Nuclear and cortical phenomena during dividing and resting cyst formation of Colpoda inflata are described. Cell division forms a cyst and produces two or four tomites. In each tomite, the right oral field results from the proliferation of the anterior extreme of a single kinety, and the left oral field results from the proliferation of four, five, or six somatic kineties. After macronuclear division, each macronuclear mass undergoes a chromatinic extrusion process. During resting cyst formation, the oral infraciliature of the vegetative cell is resorbed. The somatic kineties dispose in a radial way and some pairs of kinetosomes disappear. As in cell division, there is an extrusion process. From these results we conclude that the resting cysts of Colpoda inflata cannot be included in any group of the previous classifications for hypotrich resting cysts. Thus, we propose a new additional group to Walker and Maugel's classification called PKR (partial-kinetosome-resorbing) cysts.     

Description of the Infraciliature and Morphogenesis in the Ciliate Urotricha ondina N. Sp. (Prorodontida, Urotrichidae)

Recent works on prostomatid ciliates show that some genera of this group have a differentiated oral infraciliature and that their stomatogenesis during division involves the proliferation of only a few somatic kineties. These findings have significant implications regarding the iaxonomic status of these genera and also on the terminology used for the oral structures. In Urotricha ondina , the oral infraciliature consists of (1) a paroral kinety formed of paired kinetosomes that encircle the cytostome at the anterior pole of the cell and (2) 3 adoral organelles, each formed of 2 rows of kinetosomes, ventral in position and obliquely disposed, lying above 3 short somatic kineties that do not reach the anterior pole of the cell. This oral ciliature —formerly known as the corona and brosse, respectively—originate during stomatogenesis from the proliferation of 4 somatic kineties that lie posterior to the adoral organelles of the parental cell.     

Reconciling cladistic and genetic analyses in choreotrichid ciliates (Ciliophora, Spirotricha, Oligotrichea)

Fifty-six features of halteriid, oligotrichid, and choreotrichid ciliates are cladistically analysed, including an updated hypothesis about the evolution of the somatic ciliary patterns. Based on its morphology, Lynnella clusters with Parastrombidinopsis, Parastrombidium, and Strombidinopsis, while it is basal to the other choreotrichids in the molecular phylogenies. The two clusters of Favella species in small subunit rRNA gene trees are supported by morphological features, justifying a separation at genus and family level. The genus Favella has a smooth lorica surface and a somatic ciliary pattern comprising a left and lateral ciliary field as well as two dorsal kineties and a monokinetidal ventral kinety abutting on the right ciliary field. The new genus Schmidingerella n. gen., established for the second Favella cluster, groups with Metacylis and Rhabdonella in the molecular trees. It differs from Favella in (i) a lorica wall with reticulate surface ridges and minute openings and (ii) a ventral kinety that is distinctly apart from the right ciliary field and composed of a monokinetidal anterior and a dikinetidal posterior portion. The genera Codonaria, Codonella, and Codonellopsis are affiliated with the family Dictyocystidae, whose diagnosis is improved to include the lorica sac.     

Two new marine scuticociliates,Sathrophilus planus n. sp. and Pseudoplatynematum dengi n. sp., with improved definition of Pseudoplatynematum (Ciliophora,Oligohymenophora)

Two new marine scuticociliates, Sathrophilus planus n. sp. and Pseudoplatynematum dengi n. sp., isolated from coastal waters of Qingdao, northern China, were investigated using live observation and silver impregnations. Sathrophilus planus can be recognized by its elongate and conspicuously flattened body, ca. 16 somatic kineties, single postoral kinety, extremely elongated first kinety row of membranelle 1, and its marine habitat. Among these features, the structure of membranelle 1 is the most characteristic and enables this species to be easily distinguished from its congeners. Pseudoplatynematum dengi is characterized by the following features: cell surface conspicuously strengthened and notched; prominent spines both at anterior and posterior ends of cell; membranelles 1 and 2 three-rowed, membranelle 3 single-rowed; paroral membrane composed of two parts, anterior end of upper part extending to about level of membranelle 2; ca. 20 somatic kineties, one postoral kinety; single prolonged caudal cilium; contractile vacuole caudally positioned. The diagnosis of the genus Pseudoplatynematum was renewed to include some new characteristics revealed by silver impregnation methods.     

Strombidinopsis jeokjo n. sp. (ciliophora: choreotrichida) from the coastal waters off western Korea: morphology and small subunit ribosomal DNA gene sequence

The planktonic ciliate Strombidinopsis jeokjo n. sp. is described from Quantitative Protargol-Stained (QPS) preparations, and the sequence of the small subunit rDNA (SSU rDNA) from cultured cells is reported. This species is ovoid and bluntly tapered towards the posterior. The ranges (and mean +/- standard deviation, n = 31) of cell length, cell width, and oral diameter of the QPS-stained specimens were 100-190 microm (149 +/- 25), 60-105 microm (79 +/- 13), and 55-80 microm (64 +/- 5), respectively. Fifteen to seventeen external oral polykinetids had oral membranelle cilia 20-35 microm long. Twenty-six to twenty-eight somatic kineties were equally spaced around the cell body and extended from the oral to the posterior regions with 23-44 dikinetids per kinety. Both kinetosomes of each kinetid bore cilia 3-7 microm long. Strombidinopsis jeokjo had two ovoid macronuclei of 25-38 microm x 12-15 microm. When properly aligned, the sequence of the SSU rDNA of S. jeokjo (GenBank Accession No. AJ628250) was approximately 2% different from that of an unidentified Strombidinopsis species (GenBank Accession No. AF399132-AF399135), the closest species in the SSU rDNA sequence.     

New entodiniomorphid ciliates from the intestine of the wild African white rhinoceros belong to a new family, the Gilchristidae

Gilchristia artemis n.g., n.sp. and Digilchristia draconis n.g., n.sp. in the order Entodiniomorphida are described from the large intestine of the African white rhinoceros, and a new family Gilchristidae is proposed to contain them. These new species have a C-shaped adoral polybrachykinety, a slender vestibular polybrachykinety, and paralabial kineties along the ventral side of the adoral polybrachykinety in their retractable adoral ciliary zone, showing the same arrangement as in the rumen ciliates in the family Ophryoscolecidae. G. artemis has two skeletal plates and D. draconis one plate. In both species the dorsal skeletal plate is bow-shaped, folded in half longitudinally, twisting in the anterior part, and lying along the dorsal left side of the macronucleus. The second plate of G. artemis is slender and lies along the ventral side of the macronucleus. G. artemis has three ciliary arches and D. draconis has four arches along the dorsal and ventral sides of the body. Their arches are long and non-retractable, closely resembling those of ciliates in the families, Spirodiniidae and Cycloposthiidae, and are not analogous to the single retractable ciliary arch of the rumen ciliates in the family Ophryoscolecidae.