Dorsal Kineties Research Articles

Redefinition of the hypotrichous ciliate Uncinata, with descriptions of the morphology and phylogeny of three urostylids (Protista, Ciliophora)

We investigated the morphology, morphogenesis and small subunit rRNA gene-based phylogeny of three marine urostylids, Uncinata gigantea Bullington, 1940, Holosticha heterofoissneri Hu & Song, 2001, and Holosticha cf. heterofoissneri. The dorsal morphogenesis of Uncinata gigantea shows de novo formation of two groups of anlagen near the marginal rows. Holosticha cf. heterofoissneri demonstrates fragmentation of the first dorsal kinety anlage as in Holosticha heterofoissneri. Our population of H. heterofoissneri corresponds well with previously described populations in terms of its general morphology and ciliary pattern. Uncinata gigantea can be recognized by its large and highly contractile body, yellowish to brownish cell colour, two types of cortical granules, and 20–30 transversely oriented and densely arranged cirri in the left marginal row, which often overlie the buccal vertex. Based on the new data, especially infraciliature, the genus Uncinata is here redefined. Both the morphology and phylogenetic analyses suggest that the genus Uncinata should be classified within the family Urostylidae. In addition, both morphological and morphogenetic data suggest that Holosticha bradburyae Gong et al., 2001 should be transferred to Uncinata as U. bradburyae (Gong et al., 2001) comb. nov., due to its possession of a characteristically prominent beak-like, leftwards curved projection and the developmental mode of the dorsal kineties. This assignment is supported by the phylogenetic analyses, which placed Uncinata gigantea in a clade with U. bradburyae (Gong et al., 2001) comb. nov., and revealed only 1.13% (19 bp) difference in their SSU-rDNA gene sequence.

Taxonomy and molecular phylogeny of two novel ciliates, with establishment of a new genus, Pseudogastrostyla n. g. (Ciliophora, Hypotrichia, Oxytrichidae)

Two novel hypotrichous ciliates, Pseudogastrostyla flava n. g., n. sp. and Urosomoida subtropica n. sp., isolated from Daya Bay Mangrove Park, Huizhou, southern China, were observed in vivo and after protargol staining. Pseudogastrostyla n. g. is diagnosed by having more than 18 frontal-ventral-transverse cirri, an indistinct frontoventral row, undulating membranes in Oxytricha-pattern and dorsomarginal kinety, but lacking dorsal kinety fragmentation during morphogenesis. The monotypic species, P. flava n. sp., is characterized by its brownish body colour, brown-yellowish cortical granules mostly arranged in groups, frontoventral row terminating near mid-body, and one caudal cirrus. Urosomoida subtropica n. sp. can be recognized by having one micronucleus located between two macronuclear nodules, four transverse cirri, pretransverse ventral cirrus (V/2) anteriorly located, four dorsal kineties and three caudal cirri. Phylogenetic analyses based on SSU rRNA gene sequence data indicate that Pseudogastrostyla n. g. is nested within the oxytrichids and is most closely related to Rubrioxytricha ferruginea, and that Urosomoida subtropica n. sp. clusters with Oxytricha elegans rather than the type species, U. agilis. Nodal support values are, however, too low to draw any conclusions about the molecular systematics of the genus Urosomoida.

Morphology, ontogenesis and molecular characterization of Atractos contortus Vörösváry, 1950 and Stichotricha aculeata Wrzesniowskiego, 1866 (Ciliophora, Stichotrichida) with consideration of their systematic positions

Atractos contortus, a rare highly spiralized hypotrich ciliate, has not been studied by modern methods. Atractos contortus and Stichotricha aculeata are currently assigned to the Spirofildae. A Canadian population of A. contortus and an Idaho population of Stichotricha aculeata, were characterized using live observation, silver impregnation, scanning electron microscopy, and 18S rDNA sequencing. Atractos contortus has two frontal and one buccal cirrus, two marginal and two ventral rows arranged in left-handed helices, and four dorsal kineties. Left and right marginal rows make two and a half and three turns; left and right ventral rows are shortened. Frontoterminal, postoral, transverse and caudal cirri are absent. During morphogenesis the parental adoral zone is completely retained. Cirral rows replicate by intrakinetal and de novo processes. New right marginal and right ventral rows arise from the parental right ventral row. The parental right marginal row is morphogenetically inactive. Dorsal kineties replicate apokinetally. The parental dorsomarginal kinety and some parental marginal cirri persist for some time after cytokinesis. Phylogenetically, A. contortus groups with Uroleptus species and not spirofilids. The Idaho S. aculeata matches populations from previous reports. Monophyly of the Spirofilidae is rejected. Placement of genus Atractos in the family, Atractosidae nov. nom. is proposed.

Morphology and molecular phylogeny of an Indian population of Cyrtohymena citrina (Ciliophora, Hypotricha), including remarks on ontogenesis of Urosomoida-Notohymena-Cyrtohymena group

The oxytrichid ciliate Cyrtohymena citrina, isolated from a soil sample from India, is moderately flexible, measures about 105×35μm in life and possesses citrine cortical granules, mainly arranged around cirri and dorsal cilia. Morphology and ontogenesis was investigated using live observation and protargol impregnation, and 18S rDNA was sequenced. Ontogenesis of an Indian population of Urosomoida agilis was also investigated. All three genera included in the Urosomoida-Notohymena-Cyrtohymena group have long been characterized by the ontogenetic feature that “anlagen V and VI of proter originate de novo”. This ontogenetic feature has been considered as the sole synapomorphy and an important diagnostic feature of the group. Based on current observations on ontogenesis of C. citrina and U. agilis, and previous observations of C. shii, Notohymena saprai and N. australis, the aforesaid ontogenetic feature is no longer true for the group. Indian population of C. citrina clusters with C. muscorum, Paraurosomoida, Urosomoida, Notohymena and Paraurostyla, and is placed away from Oxytricha granulifera; all oxytrichids in the cluster show deviation(s) from any of the typical oxytrichid features like Oxytricha pattern undulating membrane, 18 frontoventral transverse cirri and fragmentation of dorsal kinety 3. Phylogenetic analyses supported non-monophyly of Cyrtohymena and other flexible-bodied oxytrichids.

Two Oxytrichids from the Ancient Lake Biwa, Japan, with Notes on Morphogenesis of Notohymena australis (Ciliophora, Sporadotrichida)

Two oxytrichid freshwater ciliates, Apoamphisiella tihanyiensis (Gellert and Tamas, 1958) Foissner, 1997 and Notohymena australis (Foissner and O’Donoghue, 1990) Berger, 1999, were recorded for the first time in Lake Biwa, a 4-million-year-old lake located at the Shiga Prefecture in Japan. Their morphology was investigated based on observations of live and protargol-impregnated material. Based on the present observation and previous descriptions, A. tihanyiensis is characterized by having an elliptical body shape, yellowish cortical granules, two long frontoventral rows, enlarged frontal and transverse cirri, highly variable numbers of frontoventral, and postoral ventral cirri, and six to 11 caudal cirri arranged in three short rows. New data confirm the presence of pretransverse ventral cirri in this species. Morphologically, N. australis differs from its congeners in having the following combination of characters: greenish cortical granules, the cirrus V/2 located slight anterior to the leftmost transverse cirrus, dorsal kinety 3 almost as long as body, and seven to 10 caudal cirri arranged in three short rows. Morphogenesis in N. australis shows the same pattern as in N. apoaustralis but differs from that of other congeners in the origin of oral primordium and the formation of more than just three caudal cirri.

Biogeographic specializations of two large hypotrich ciliates: Australocirrus shii and A. australis and proposed synonymy of Australocirrus and Cyrtohymenides

Using standard methods, we studied the morphology and distribution of an Australian population of Australocirrus shii (Shi et al., 1997) nov. comb. and a Jamaican population of A. australis (Foissner, 1995) nov. comb. We identified three features, not or rarely used earlier, that distinguish Australocirrus shii from A. australis: the distance between the anterior pretransverse cirrus and the anteriormost transverse cirrus (5–8% vs. 1.5–1.7% of body length), the arrangement of the transverse cirri (3+2 vs. an oblique row), and the resting cyst macronuclear nodules (separate vs. fused). Australocirrus shii has been reported from Asia and Australia while A. australis is possibly restricted to the Neotropic. Because of problems in getting voucher materials of A. shii, we emphasise that permanent slides should be deposited in international repositories. Based on previous studies and new data, especially a refined interpretation of the shape of the paroral membrane, we suggest synonymy of Cyrtohymenides and Australocirrus. Thus, Cyrtohymena (Cyrtohymenides) shii, C. (Cyrtohymenides) aspoecki, and C. (Cyrtohymenides) australis are transferred to Australocirrus which is, inter alia, defined by a moderately to distinctly curved, but not recurved, paroral membrane, multiple fragmentation of dorsal kinety 3 and three or more dorsomarginal kineties.

Morphology, morphogenesis, and molecular phylogeny of Sterkiella tetracirrata n. sp. (Ciliophora, Oxytrichidae), from the Silent Valley National Park, India

The morphology and morphogenesis during cell division of Sterkiella tetracirrata n. sp., isolated from a soil sample collected from the Silent Valley National Park, Kerala, India, were investigated using live observation, protargol staining and scanning electron microscopy. The new species differs from its congeners by the following combination of features: cell size in vivo 85–110×35–50μm, on average 84×37μm in protargol preparations; four ellipsoidal macronuclear nodules; 31 adoral membranelles; 17 frontal-ventral-transverse cirri consisting of three frontal, four frontoventral, one buccal, three ventral, two pretransverse and invariably four transverse cirri; resting cyst with separate macronuclear nodules. Sterkiella tetracirrata differs from the similar species S. terricola in the number of transverse cirri (invariably 4 vs. 3) and in the number of adoral membranelles (24–35 vs. 22 or 23). Morphogenesis resembles that of its congeners S. nova and S. histriomuscorum. Phylogenetic analyses based on SSU rRNA gene sequences consistently place the new species within the stylonychine oxytrichids, clustering closer to Gastrostyla steinii than to either S. cavicola or S. histriomuscorum. The analyses support the morphological evidence (e.g., similarity in the oral apparatus and the dorsal kinety pattern) that Gastrostyla and Pattersoniella evolved from a Sterkiella-like ancestor.

A general overview of the typical 18 frontal-ventral-transverse cirri oxytrichidae s. l. genera (Ciliophora, Hypotrichia)

Oxytrichidae s. l. ciliates usually have 18 frontal-ventral-transverse cirri which are clustered to six distinct groups usually originating from six longitudinal primordia segregating 1, 3, 3, 3, 4, 4 cirri. During morphogenesis, three dorsal kineties anlagen are primarily formed. Fragmentation of kinety 3 usually present, while sometimes secondarily lost. Dorsomarginal kineties are formed, while sometimes lost. Oxytrichids tend to have overlapping characters, e.g. cell shape and size, infraciliature, pellicle features. This makes a great problem for genera separation. In the present work, all typical 18 frontal-ventral-transverse-cirri Oxytrichidae s. l. genera were revised systematically based on their living morphology, ciliature patterns and dorsal morphogenetic features. The outline of the genera, the schematic illustrations, and the key to typical 18 frontal-ventral-transverse-cirri genera of Oxytrichidae s. l. were clarified. Additionally, some morphological and morphogenetic patterns were summarized and compared.

Morphology and Molecular Phylogeny of Pseudocyrtohymena koreana n. g., n. sp. and Antarctic Neokeronopsis asiatica Foissner et al., 2010 (Ciliophora, Sporadotrichida), with a Brief Discussion of the Cyrtohymena Undulating Membranes Pattern

We discovered a new brackish water oxytrichid Pseudocyrtohymena koreana n. g., n. sp. in South Korea and investigated the new species on the basis of morphology, ontogenesis, and 18S rRNA gene sequences. The new genus has the 18 frontal-ventral-transverse cirri of typical oxytrichids with flexible body, cortical granules, Cyrtohymena undulating membranes (UM), and one left and one right marginal cirral row. Ontogenesis of the new species indicated that dorsal kinety anlage 3 stretches within the parental row without any fragmentations (Urosomoida pattern) and exclusively forms all caudal cirri. The new genus is morphologically similar to Cyrtohymena Foissner, 1989, but has the following distinctive features: (i) caudal cirri absent in dorsal kineties 1 and 2 (vs. present in Cyrtohymena); and (ii) dorsal kinety 3 nonfragmented (vs. fragmented in Cyrtohymena). Further, we collected an additional species Neokeronopsis asiatica Foissner et al. 2010, from King George Island, Antarctica, and the species shares the morphology of UM with Cyrtohymena. Herein, we describe the previously unidentified characteristics of N. asiatica (i.e., cortical granules, body flexibility, contractile vacuole, and 18S rRNA gene sequence). In addition, we obtained two 18S rRNA gene sequences from Cyrtohymena muscorum and Parasterkiella thompsoni to expand samples for phylogenetic analysis. Our 18S rRNA gene tree supports the hypothesis that the Cyrtohymena UM pattern might have evolved several times in hypotrichs (e.g., Neokeronopsidae, Oxytrichinae, and Stylonychinae).

Molecular phylogeny of an Indian population of Kleinstyla dorsicirrata (Foissner, 1982) Foissner et al., 2002. comb. nov. (Hypotrichia, Oxytrichidae): an oxytrichid with incomplete dorsal kinety fragmentation.

Kleinstyla dorsicirrata (Foissner, 1982) Foissner etal., 2002. comb. nov. (basionym: Gastrostyla dorsicirrata) is a slightly flexible oxytrichid, measuring about 88-115×27-46μm in life and possesses cortical granules. Kleinstyla dorsicirrata is the only oxytrichid known so far with incompletely fragmented dorsal kinety. Morphological and morphogenetic data recognise K. dorsicirrata as nonstylonychine oxytrichid. Molecular phylogeny of an Indian population was inferred using 18S rRNA gene sequences and was examined with respect to oxytrichids exhibiting variation in dorsal kinety fragmentation. Kleinstyla dorsicirrata clusters with Oxytricha lanceolata; this proximity is quite significant as both show deviation from typical oxytrichid fragmentation of dorsal kinety. Molecular phylogeny of Indian population confirms its nonstylonychine oxytrichid status.

Morphology, ontogenetic features and SSU rRNA gene-based phylogeny of a soil ciliate, Bistichella cystiformans spec. nov. (Protista, Ciliophora, Stichotrichia).

The morphology, ontogeny and SSU rRNA gene-based phylogeny of Bistichella cystiformans spec. nov., isolated from the slightly saline soil of a mangrove wetland in Zhanjiang, southern China, were investigated. The novel species was characterized by having five to eight buccal cirri arranged in a row, three to five transverse cirri, four macronuclear nodules aligned, and 17-32 and 20-34 cirri in frontoventral rows V and VI, respectively, both extending to the transverse cirri. The main ontogenetic features of the novel species were as follows: (1) the parental adoral zone of the membranelles is completely inherited by the proter; (2) the frontoventral and transverse cirri are formed in a six-anlagen mode; (3) basically, the frontal-ventral-transverse cirral anlagen II-V generate one transverse cirrus each at their posterior ends, while anlage VI provides no transverse cirrus; (4) both marginal rows and dorsal kineties develop intrakinetally, no dorsal kinety fragment is formed; and (5) the macronuclear nodules fuse into a single mass at the middle stage. Phylogenetic analyses based on the SSU rRNA gene showed that the novel species groups with the clade containing Bistichella variabilis, Parabistichella variabilis, Uroleptoides magnigranulosus and two species of the genus Orthoamphisiella. Given present knowledge, it was considered to be still too early to come to a final conclusion regarding the familial classification of the genus Bistichella; further investigations of key taxa with additional molecular markers are required.

Morphology, morphogenesis and molecular phylogeny of a soil ciliate, Pseudouroleptus caudatus caudatus Hemberger, 1985 (Ciliophora, Hypotricha), from Lhalu Wetland, Tibet

Pseudouroleptus caudatus caudatus Hemberger, 1985, a soil ciliate isolated from Tibet, was studied in vivo and after protargol impregnation. The Tibetan population is mainly characterized by: elongate body with narrowly rounded anterior end and tapered posterior end; length of buccal area relative to body length ca. 20–25%; cortical granules colourless, round, densely distributed throughout sub-pellicular layer of cell; one parabuccal cirrus; post-peristomial cirrus lacking in 75% of specimens analyzed; left and right ventral rows commence at same level; four dorsal kineties; 3–6 inconspicuous caudal cirri; two macronuclear nodules; 2–7 micronuclei; contractile vacuole located at about 33% of body length near left margin. Morphogenesis is characterized by: (1) parental adoral zone of membranelles retained completely; (2) anterior segments of streaks VI and IV and the whole of streak V form the anterior, middle, posterior segments of the mixed row, respectively; (3) right ventral row originates de novo in both daughter cells; (4) marginal rows develop intrakinetally; (5) dorsal kinety anlage 3 develops de novo in the proter and intrakinetally in the opisthe; and (6) the two macronuclear nodules fuse into a single mass which then divides. Molecular phylogenies corroborate the morphological identification and support the close relationship between Pseudouroleptus and Strongylidium.

Microscopic investigation of three species of Diophrys (Ciliophora, Euplotida, Uronychiidae) from Japan, including Diophrys peculiaris nov. spec

Three species of Diophrys, D. peculiaris nov. spec., D. cf. scutum and D. oligothrix, isolated from the New Nagasaki Fishing Port, Nagasaki, Japan, were investigated using live observation and protargol impregnation. Diophrys peculiaris nov. spec. can be recognized by having two characteristic clusters of rod-like structures and two groups of dikinetids located on anterior dorsal portion of cell. Morphogenetic data show that this part of the life cycle basically proceeds as in congeners, except for the formation of dikinetids under the rod-like structures. In the opisthe, the origin of dikinetids under the rod-like structures is still unknown, but the old dikinetids under the rod-like structures may be retained by the proter. The Japanese population of Diophrys cf. scutum resembles other populations of D. scutum well except for moniliform macronuclear segments. Our populations of D. oligothrix correspond well with other populations in terms of general morphology and ciliary pattern, in particular the continuous dorsal kineties with loosely arranged cilia.

Morphology, morphogenesis and molecular phylogeny of a new marine ciliate, Trichototaxis marina n. sp. (Ciliophora, Urostylida)

The live morphology, infraciliature and morphogenesis of a new urostylid ciliate, Trichototaxis marina n. sp., collected from coastal water in Qingdao, China, were studied based on the observations of live and silver stained specimens. The new species is characterised as follows: body very flexible and contractile, slight to brick-reddish in colour due to irregularly-shaped, brick-red pigments; ca. 70 adoral membranelles; about 17 frontal cirri arranged in a bicorona; average 67 midventral pairs, the right base of each pair being conspicuously larger than the left base; five to seven transverse cirri; constantly two frontoterminal, one buccal and two pretransverse ventral cirri; two or three left marginal rows; right and innermost left marginal rows with 56–92 and 66–106 cirri, respectively; six bipolar dorsal kineties; more than 100 macronuclear nodules. The characteristic morphogenetic feature in T. marina is the development of the left marginal rows, that is, only one left marginal row is newly built the other one or two being retained from the parental cell. Phylogenetic analyses based on small subunit ribosomal gene sequence data reveal a close relationship of T. marina with members of family Pseudokeronopsidae.

Taxonomy and phylogeny of two species of the genus Deviata (Protista, Ciliophora) from China, with description of a new soil form, Deviata parabacilliformis sp. nov.

The morphology and morphogenesis of a soil hypotrichous ciliate, Deviata parabacilliformis sp. nov., isolated from northern China, were investigated. D. parabacilliformis measures about 75-210 × 25-60 µm in vivo, with an elongate and flexible body. It possesses one right marginal row, two to four left marginal rows and three dorsal kineties. The main morphogenetic features of D. parabacilliformis are: (i) the oral primordium originates de novo; (ii) anlage IV of the opisthe originates from parental frontoventral row V, anlage V originates de novo, and anlage VI forms from frontoventral row VI; and (iii) anlage I of the proter originates from the anterior portion of the parental paroral, anlage II originates from the buccal cirrus, anlage III originates from the parabuccal cirri, anlage IV originates from parental frontoventral row IV and anlage V forms from the anterior of parental frontoventral row VI. The morphology of an edaphic population of another species of the genus Deviata, Deviata bacilliformis (Gelei 1954) Eigner 1995, was also investigated. This work also provides the first record of SSU rRNA gene sequences for species of the genus Deviata. Molecular phylogenetic analysis suggests that Deviata is not monophyletic, and its position is poorly resolved due to weak phylogenetic signal of the 18S marker in the Stichotrichida.

Morphology and molecular phylogeny of Apoterritricha lutea n. g., n. sp. (Ciliophora, Spirotrichea, Hypotrichia): a putative missing link connecting Cyrtohymena and Afrokeronopsis.

A new hypotrichous ciliate, Apoterritricha lutea n. g., n. sp., was discovered in a sample of a terrestrial liverwort from Korea. Its morphology was studied using detailed in vivo observation and protargol impregnation. Its phylogenetic relationships were revealed by analyses of the 18S rRNA gene. This new taxon is characterized by a combination of the following traits: (i) ellipsoidal to narrowly ellipsoidal body with an average size of 230×85μm; (ii) two macronuclear nodules and two to five micronuclei; (iii) golden yellow cortical granules, forming small groups along the microtubular appendages of cirri, adoral membranelles, and dorsal kineties; (iv) typically three frontal cirri, one buccal cirrus, four frontoventral cirri, seven midventral cirri, two pretransverse cirri, seven transverse cirri, ca. 38 left, and ca. 36 right marginal cirri; and (v) on average six dorsal kineties, three dorsomarginal kineties, and three caudal cirri. In molecular phylogenies, A. lutea clusters with strong support within a clade containing Afrokeronopsis aurea and several "typical" oxytrichids having golden yellow to brown cortical granules. In this light we propose a hypothesis that is not unambiguously rejected by the present phylogenetic analyses, which shows how the Afrokeronopsis-like pattern could have evolved from a Rubrioxytricha-like ancestor via an Apoterritricha-like stage by cirri-multiplication.

Molecular phylogeny and ontogeny of a new ciliate genus, Paracladotricha salina n. g., n. sp. (Ciliophora, Hypotrichia).

A hypotrichous ciliate, Paracladotricha salina n. g., n. sp., was discovered in hypersaline waters (salinity about 80‰) from Qingdao, China. Its morphology and some major ontogenetic stages were studied and the phylogenetic position was estimated using standard methods. Paracladotricha salina is characterized by a flexible, more or less slender body (size 50–120 × 20–35 μm), a gonostomatid oral apparatus, one short and two long frontoventral rows, four macronuclear nodules, almost completely reduced dorsal kineties 1–3, and a loss of several parts of the ciliature, namely, the slightly shortened ciliary row of the adoral membranelles, the paroral, and the buccal, the postoral and pretransverse ventral, the transverse, and the caudal cirri. The ontogenesis is rather simple: anlage II of both filial products and anlage III of the opisthe originate de novo, while anlagen IV and V are formed within the parental rows. This combination of features requires the establishment of a new genus, Paracladotricha, which is, according to the morphological data, closely related to Schmidingerothrix and Cladotricha. The small-subunit rRNA gene was sequenced, indicating that P. salina is, as also demonstrated by the oral apparatus, a member of the gonostomatids. We provide a first, vague hypothesis about the phylogenetic relationships of the Gonostomatidae, Cladotrichidae, and Schmidingerotrichidae. However, since molecular data of the type species of these higher taxa are lacking, their validity and relationships remain obscure.

Morphology and phylogenetic analysis of two oxytrichid soil ciliates from China, Oxytricha paragranulifera n. sp. and Oxytricha granulifera Foissner and Adam, 1983 (Protista, Ciliophora, Hypotrichia).

The morphology and infraciliature of two hypotrichous ciliates, Oxytricha paragranulifera n. sp. and Oxytricha granulifera Foissner and Adam, 1983, collected respectively from the surface of a sandy soil in the Huguang mangrove forest, Zhanjiang, China, and the surface of soil in a forest beside Ziwu Road, Xian, north-west China, were examined. O. paragranulifera n. sp. is characterized by an elongate body with slightly tapered anterior end, two macronuclear nodules and two micronuclei, paroral and endoral in Stylonychia-pattern, colourless cortical granules distributed in clusters or irregular short rows, adoral zone occupying 37 % of the body length, marginal rows almost confluent posteriorly, six dorsal kineties and three caudal cirri, caudal cirri and dorsal bristles almost indistinguishable when viewed in vivo. The well-known O. granulifera Foissner and Adam, 1983 was also redescribed and can be separated from the novel species by having cortical granules arranged along dorsal kineties and marginal rows on both sides (vs grouped in clusters as well as in short irregular rows), paroral and endoral in Oxytricha-pattern (vs in Stylonychia-pattern), macronuclear nodules obviously detached (vs adjacent) and a non-saline terrestrial habitat (vs saline terrestrial). The separation of these two taxa is also firmly supported by the molecular data, which show a significant difference between the two in their SSU rRNA gene sequences (similarity 97.1 %). Phylogenetic analyses based on SSU rRNA gene sequence data suggest a close relationship within the Oxytrichidae assemblage between O. paragranulifera n. sp. and O. granulifera.

Morphology and molecular phylogeny of Pseudouroleptus jejuensis nov. spec., a new soil ciliate (Ciliophora, Spirotrichea) from South Korea

A new soil ciliate, Pseudouroleptus jejuensis, was discovered from Jeju Island, South Korea and described based on live observation, protargol impregnation, and SSU rRNA gene sequence analyses. Pseudouroleptus jejuensis differs from other congeneric species mainly by number of dorsal kineties (5 vs. 4). Based on our observation of late dividers, we confirm that the dorsal kinety anlage 3 forms 3 kineties (i.e., dorsal kineties 3–5), and the dorsal kinety anlagen 1–3 form 3–5/1–2/0 caudal cirri, respectively. Our gene trees support the assignment of this new species in Pseudouroleptus to full supporting values.

Morphology of Clapsiella magnifica gen. n., sp. n., a new hypotrichous ciliate with a curious dorsal ciliary pattern

The present work describes the morphology and infraciliature of a new hypotrichous ciliate, Clapsiella magnifica gen. n., sp. n., found in rewetted soil from a temporal pond in Argentina. It was studied by means of live observation and protargol impregnation. Its main diagnostic features are: Flexible hypotrich measuring 250–320μm×70–140μm in vivo; two macronuclear nodules and 4–6 micronuclei. Single contractile vacuole. Cytoplasm transparent, cortical granules absent. Somatic ciliature composed of a tricorona of cirri, three buccal(?) cirri, 6–9 ventral rows, 3–5 right marginal(?) rows, one left marginal row, and 12–17 transverse cirri. Dorsal pattern rather complicated, with about 14 kineties and kinety fragments, with scattered kinetids among them; 17–28 caudal cirri arranged in three rows on dorsal kineties 1, 3, and 7. Remarkably, dorsal kinetids have two or four basal bodies, bearing a stiff bristle arising from left anterior basal body. Adoral zone composed of 70–92 membranelles, occupying about 40% of body length in protargol preparations; paroral and endoral curved, resembling a cyrtohymenid pattern. The peculiar dorsal ciliary arrangement and the unique combination of other characters require the establishment of a new genus for this new species, which is considered incertae sedis in the Hypotricha but possibly related to the oxytrichids.