Fig 1 - uploaded by Weibo Song
Content may be subject to copyright.
Morphology and infraciliature of Eurystomatella sinica n. sp. from life (a–c, h) and after staining with silver nitrate (i) and protargol impregnation (d–g, j, k). (a) Ventral view of typical individual; note the elongate caudal cilia (arrows). (b) Lateral view. (c) Pattern of movement. (d) Ventral view of anterior portion of body, showing the buccal apparatus; arrow indicates the ‘anterior’ end of the paroral membrane (PM) and double arrowheads mark its ‘posterior’ end. (e, f) Nucleoli in the macronucleus. (g) Silverline system; arrows indicate extrusomes. (h) Ventral view of a slender specimen, showing the deeply excavated buccal area where the cytostome is located (arrow). (i) Buccal field; arrow marks the cytostome. Note the highly developed oral fibres (OF). (j, k) Ventral and dorsal views showing the general infraciliature; arrow in (j) indicates posterior end of PM. CV, Contractile vacuole; CVP, contractile vacuole pore; FV, food vacuole; M1, M2a, M2b and M3, oral membranelles 1–3; Ma, macronucleus; PM, paroral membrane; SK1 and SKn, first and last somatic kineties. Bars, 25 m m.
Source publication
Recently, an undescribed marine ciliate was isolated from China. Investigation of its morphology and infraciliature revealed it as an undescribed species representing a new genus, Eurystomatella n. gen., the type of the new family Eurystomatellidae n. fam. The new family is defined by close-set, apically positioned oral membranelles and a dominant...
Contexts in source publication
Context 1
... Living individuals usually measuring approximately 60630 mm, with elongate to slender oval shape, broadly rounded at both ends, with anterior end slightly truncated (Fig. 1a, h; Fig. 2b, j). Body dorso- ventrally flattened, with height/width ratio of approxi- mately 1 : 2. Buccal field comprising approximately 75 % of the body length and 70 % of the body width (Fig. 2j), surrounded by a ridged ring (or base of paroral membrane), surface hardly invaginated except for upper third where the cytostome is located (Fig. 1h; ...
Context 2
... (Fig. 1a, h; Fig. 2b, j). Body dorso- ventrally flattened, with height/width ratio of approxi- mately 1 : 2. Buccal field comprising approximately 75 % of the body length and 70 % of the body width (Fig. 2j), surrounded by a ridged ring (or base of paroral membrane), surface hardly invaginated except for upper third where the cytostome is located (Fig. 1h; Fig. 2c, arrow). Pellicle ridged, characteristically notched in profile (readily visible only under high magnification; Fig. 2c). No extrusomes detectable in living cell, but revealed by silver nitrate impregnation to be densely arranged along somatic kineties ( Fig. 1g, arrows; Fig. 3b). Cytoplasm colourless to slightly greyish, often packed ...
Context 3
... hardly invaginated except for upper third where the cytostome is located (Fig. 1h; Fig. 2c, arrow). Pellicle ridged, characteristically notched in profile (readily visible only under high magnification; Fig. 2c). No extrusomes detectable in living cell, but revealed by silver nitrate impregnation to be densely arranged along somatic kineties ( Fig. 1g, arrows; Fig. 3b). Cytoplasm colourless to slightly greyish, often packed with numerous large granules (Fig. 1a, b, h; Fig. 2b, h, j). Usually one oval macronucleus with many globular nucleoli present ( Fig. 1e, f; Fig. 3e), but several macronuclei (up to six) in some cells. Contractile vacuole located approximately one-fifth of the body length from ...
Context 4
... ridged, characteristically notched in profile (readily visible only under high magnification; Fig. 2c). No extrusomes detectable in living cell, but revealed by silver nitrate impregnation to be densely arranged along somatic kineties ( Fig. 1g, arrows; Fig. 3b). Cytoplasm colourless to slightly greyish, often packed with numerous large granules (Fig. 1a, b, h; Fig. 2b, h, j). Usually one oval macronucleus with many globular nucleoli present ( Fig. 1e, f; Fig. 3e), but several macronuclei (up to six) in some cells. Contractile vacuole located approximately one-fifth of the body length from posterior end, located left of the mid-line, measuring approximately 8 mm in diameter (Fig. 1a, b, h). No pulsation of ...
Context 5
... 2c). No extrusomes detectable in living cell, but revealed by silver nitrate impregnation to be densely arranged along somatic kineties ( Fig. 1g, arrows; Fig. 3b). Cytoplasm colourless to slightly greyish, often packed with numerous large granules (Fig. 1a, b, h; Fig. 2b, h, j). Usually one oval macronucleus with many globular nucleoli present ( Fig. 1e, f; Fig. 3e), but several macronuclei (up to six) in some cells. Contractile vacuole located approximately one-fifth of the body length from posterior end, located left of the mid-line, measuring approximately 8 mm in diameter (Fig. 1a, b, h). No pulsation of contractile vacuole detected. One large food vacuole, often irregular in shape, ...
Context 6
... granules (Fig. 1a, b, h; Fig. 2b, h, j). Usually one oval macronucleus with many globular nucleoli present ( Fig. 1e, f; Fig. 3e), but several macronuclei (up to six) in some cells. Contractile vacuole located approximately one-fifth of the body length from posterior end, located left of the mid-line, measuring approximately 8 mm in diameter (Fig. 1a, b, h). No pulsation of contractile vacuole detected. One large food vacuole, often irregular in shape, frequently located at posterior end of cell (Fig. 1a, b, ...
Context 7
... (up to six) in some cells. Contractile vacuole located approximately one-fifth of the body length from posterior end, located left of the mid-line, measuring approximately 8 mm in diameter (Fig. 1a, b, h). No pulsation of contractile vacuole detected. One large food vacuole, often irregular in shape, frequently located at posterior end of cell (Fig. 1a, b, ...
Context 8
... of buccal apparatus conspicuously long (about 30- 40 mm), never extending out strongly like those of some other scuticociliates (e.g. Pleuronema), lying flat and pointing toward the posterior within the buccal field ( Fig. 1a; Fig. 2e). Cell with approximately ten elongate (30 mm long) caudal cilia radiating conspicuously away from body ( Fig. 1a, b; Fig. 2b, d, g). Somatic cilia approximately 10 mm in length. Very characteristic move- ment as follows: frequently lying completely stationary on the bottom for long periods (.1 min) with all cilia stiffly spread, then ...
Context 9
... of buccal apparatus conspicuously long (about 30- 40 mm), never extending out strongly like those of some other scuticociliates (e.g. Pleuronema), lying flat and pointing toward the posterior within the buccal field ( Fig. 1a; Fig. 2e). Cell with approximately ten elongate (30 mm long) caudal cilia radiating conspicuously away from body ( Fig. 1a, b; Fig. 2b, d, g). Somatic cilia approximately 10 mm in length. Very characteristic move- ment as follows: frequently lying completely stationary on the bottom for long periods (.1 min) with all cilia stiffly spread, then crawling actively with jerking motion; when swimming (observed infrequently), moving moderately fast with rotation around the main ...
Context 10
... Somatic cilia approximately 10 mm in length. Very characteristic move- ment as follows: frequently lying completely stationary on the bottom for long periods (.1 min) with all cilia stiffly spread, then crawling actively with jerking motion; when swimming (observed infrequently), moving moderately fast with rotation around the main axis of body (Fig. 1c), then remaining very quietly suspended in the water at the same spot for long ...
Context 11
... kineties numbering 13-15 and terminating ante- riorly at small, non-ciliated apical plate; large, non-ciliated, post-oral field on ventral side ( Fig. 1i, j; Fig. 3g). Scutica not observed. Somatic kineties composed of dikinetids in anterior half of body and monokinetids in posterior half (Fig. 1j, k). Segment of kinety 1 posterior to buccal field invariably composed of dikinetids (Fig. 3g, ...
Context 12
... kineties numbering 13-15 and terminating ante- riorly at small, non-ciliated apical plate; large, non-ciliated, post-oral field on ventral side ( Fig. 1i, j; Fig. 3g). Scutica not observed. Somatic kineties composed of dikinetids in anterior half of body and monokinetids in posterior half (Fig. 1j, k). Segment of kinety 1 posterior to buccal field invariably composed of dikinetids (Fig. 3g, ...
Context 13
... apparatus as shown in Figs 1(d, i, j) and 3(c, d, h). Paroral membrane (PM) composed of closely spaced dikinetids, consisting of an almost completely closed ring except at anterior end where membranelles are located. ...
Context 14
... system composed of rectangular, transversely orientated units with interkinetal space to the right of each kinety ( Fig. 1g; Fig. 3i). Approximately ten oral fibres (oral ribs) converging on cytostome ( Fig. 1i; Fig. 3a, arrow- heads). Single contractile vacuole pore (CVP) located on the left side immediately posterior to the buccal field ( Fig. 1i, j; Fig. ...
Context 15
... system composed of rectangular, transversely orientated units with interkinetal space to the right of each kinety ( Fig. 1g; Fig. 3i). Approximately ten oral fibres (oral ribs) converging on cytostome ( Fig. 1i; Fig. 3a, arrow- heads). Single contractile vacuole pore (CVP) located on the left side immediately posterior to the buccal field ( Fig. 1i, j; Fig. ...
Context 16
... system composed of rectangular, transversely orientated units with interkinetal space to the right of each kinety ( Fig. 1g; Fig. 3i). Approximately ten oral fibres (oral ribs) converging on cytostome ( Fig. 1i; Fig. 3a, arrow- heads). Single contractile vacuole pore (CVP) located on the left side immediately posterior to the buccal field ( Fig. 1i, j; Fig. ...
Citations
... Recently, more taxa in the subclass Scuticociliatia have been investigated using a combination of morphological and molecular tools, e.g. live observation, silver staining preparations, and nuclear ribosomal DNA sequence analyses (Fan et al., 2014(Fan et al., , 2017Liu et al., 2016;Miao et al., 2010;Zhang et al., 2018). Furthermore, phylogenomic studies related to the subclass Scuticociliatia have been performed, but only two or three taxa were sampled (Feng et al., 2015;Gentekaki et al., 2017). ...
... The family Eurystomatellidae (Miao et al. 2010), comprising the genera Eurystomatella and Wilbertia, was assigned to the order Pleuronematida. It was characterized by an almost completely circular paroral membrane and showed a close relationship to the family Ctedoctematidae (Gao et al., 2013;Miao et al., 2010). ...
... The family Eurystomatellidae (Miao et al. 2010), comprising the genera Eurystomatella and Wilbertia, was assigned to the order Pleuronematida. It was characterized by an almost completely circular paroral membrane and showed a close relationship to the family Ctedoctematidae (Gao et al., 2013;Miao et al., 2010). In the present study, Eurystomatellidae is monophyletic based on the concatenated data ( Fig. 1). ...
... Jung et al. (2007) found that a scuticociliate isolate (YS1 strain) from olive flounder, identified as M. avidus, has one or two paroral membranes and two or three oral polykinetids, the authors concluded that the morphology of buccal structures 'cannot be used as a consistent key for identification of the species'. However, variability reported by Jung et al. (2007), might reflect different stages in the development of these buccal structures during stomatogenesis, which is very common in several species of scuticociliates (Miao et al. 2010). Some studies clearly show that M. avidus has a continuous paroral membrane; only in the first phases of stomatogenesis (during the transformation of microstomes into to macrostomes), is the paroral membrane divided, with a small segment at the posterior end (Gómez-Saladín and Small, 1993a). ...
Scuticociliatosis is a severe disease in farmed flatfish. However, the causative agent is not always accurately identified. In this study, we identified two isolates of scuticociliates from an outbreak in cultured fine flounder Paralichthys adspersus. Scuticociliate identification was based on morphological data, examination of life stages and the use of molecular approaches. The isolates were compared with a strain of Philasterides dicentrachi from turbot Scophthalmus maximus and with a strain deposited in the American Type Culture Collection as Miamiensis avidus ATCC® 50180™. The use of morphological, biological and molecular methods enabled us to identify the isolates from the fine flouder as P. dicentrarchi. Comparison of P. dicentrachi isolates and M. avidus revealed some differences in the buccal apparatus. Unlike P. dicentrarchi, M. avidus has a life cycle with three forms: macrostomes (capable of feeding on P. dicentrarchi), microstomes and tomites. Additionally, we found differences in the 18S rRNA and α- and β-tubulin gene sequences, indicating that P. dicentrarchi and M. avidus are different species. We therefore reject the synonymy/conspecificity of the two taxa previously suggested. Finally, we suggest that a combination of morphological, biological, molecular (by multigene analysis) and serological techniques could improve the identification of scuticociliates parasites in fish.
... Phylogenetic analyses based on single-gene and concatenated data, secondary structural analyses and predicted topology tests have been carried out to expand our understanding of phylogeny within the subclass Scuticociliatia. The main results are summarized as follows (Fig. 5): (1) The order Philasterida is a well-supported lineage although the evolutionary relationships among most of its families remain unresolved (Gao et al. 2012;Pan et al. 2013); (2) in all analyses the thigmotrichids are nested within the order Pleuronematida and so should be regarded as a suborder within Pleuronematida ; (3) the loxocephalids are polyphyletic, being basal to the core scuticociliates and most closely related to the subclasses Astomatia and Apostomatia, and should be separated from the order Philasterida (Gao et al. 2013;Li et al. 2006;Zhang et al. 2010Zhang et al. , 2011; (4) Parauronema is a junior synonym of Uronema; consequently, Parauronematidae becomes a junior synonym of Uronematidae (Gao et al. 2012); (5) the families Orchitophryidae, Uronematidae, Cyclidiidae, Loxocephalidae and Cinetochilidae are all non-monophyletic (Gao et al. 2012(Gao et al. , 2013; (6) the genera Metanophrys, Uronema, Cyclidium, and Protocyclidium are all non-monophyletic (Gao et al. 2012); (7) four new genera were established, Eurystomatella, Wilbertia, Acucyclidium, and Paramesanophrys (Fan et al. 2011;Miao et al. 2010). ...
Due to complex morphological and convergent morphogenetic characters, systematics of ciliates has long been ambiguous. Since 1990, Laboratory of Protozoology, Ocean University of China, in collaboration with other research groups worldwide, has carried out a series of integrative investigations on ciliate systematics. To date, genomic DNA has been extracted from about 1700 ciliate strains, and phylogenetic analyses have been performed for two thirds orders. Main findings are: 1) Classifications of about 50 hypotrichous species have been resolved, although the monophylies of three hypotrichous orders remain unconfirmed; 2) Euplotia and two orders and all seven families within them are monophyletic assemblages; 3) Lynnella represents an order-level taxon, and is separated from two sister monophyletic subclasses Oligotrichia and Choreotrichia; 4) Peritrich families Zoothamniidae and Vorticellidae are separated from each other, and Zoothamnium exhibits a high genetic diversity; 5) Scuticociliate order Philasterida is monophyletic and separated from loxocephalids, and the thigmotrichids is a suborder within Pleuronematida; 6) 14 classes were recovered including one new class Protocruziea, and Mesodiniea is basal to subphyla Intramacronucleata and Postciliodesmatophora; 7) Mitochondrial cytochrome c oxidase subunit I heteroplasmy was reported in ciliates for the first time, and candidate barcoding genes for Frontonia species identification were identified.
... In the past two decades, an extensive body of work on the ciliate fauna in Chinese coastal waters has revealed extremely high diversity of this group of organisms (e.g. Fan et al. 2011a,b;Gong and Song 2008;Liu et al. 2016;Long et al. 2006Long et al. , 2007aMiao et al. 2010;Pan et al. 2016Pan et al. , 2011Pan et al. , 2015aSong 2000;Song et al. 2003;Wang et al. 2008aWang et al. ,b,c, 2009Xu et al. 2015). Meanwhile, those species that lack detailed documentation, especially pleuronematids and philasterids have been re-investigated using standard methods in order to circumscribe morphospecies (e.g. ...
Five scuticociliates, collected from China, were morphologically studied using standard methods One represents a new member of the genus Falcicyclidium, F. citriforme nov. spec., which can be recognised mainly by a combination of the following characters: usually two macronuclear nodules, buccal field about half of body length, ten somatic kineties, about 22 kinetal units in somatic kinety 1 and n, and excretory pore near posterior end of somatic kinety n. A redescription for Biggaria bermudensis was provided to include the feature of scutica and argyrome based on new isolate, and variations between different isolates were also discussed. The new population of Sathrophilus holtae differs from the type population by two postoral kineties and fewer kinetal units in the scutica. Its stomatogenesis belongs to the scuticobuccokinetal type, which shows similarities with Dexiotricha among loxocephalids. Morphometric data and brief descriptions were supplied for another two species, i.e., Protocyclidium citrullus and Cyclidium varibonneti.
... Phylogenetic analyses based on single-gene and concatenated data, secondary structural analyses and predicted topology tests have been carried out to expand our understanding of phylogeny within the subclass Scuticociliatia. The main results are summarized as follows (Fig. 5): (1) The order Philasterida is a well-supported lineage although the evolutionary relationships among most of its families remain unresolved (Gao et al. 2012;Pan et al. 2013); (2) in all analyses the thigmotrichids are nested within the order Pleuronematida and so should be regarded as a suborder within Pleuronematida ; (3) the loxocephalids are polyphyletic, being basal to the core scuticociliates and most closely related to the subclasses Astomatia and Apostomatia, and should be separated from the order Philasterida (Gao et al. 2013;Li et al. 2006;Zhang et al. 2010Zhang et al. , 2011; (4) Parauronema is a junior synonym of Uronema; consequently, Parauronematidae becomes a junior synonym of Uronematidae (Gao et al. 2012); (5) the families Orchitophryidae, Uronematidae, Cyclidiidae, Loxocephalidae and Cinetochilidae are all non-monophyletic (Gao et al. 2012(Gao et al. , 2013; (6) the genera Metanophrys, Uronema, Cyclidium, and Protocyclidium are all non-monophyletic (Gao et al. 2012); (7) four new genera were established, Eurystomatella, Wilbertia, Acucyclidium, and Paramesanophrys (Fan et al. 2011;Miao et al. 2010). ...
... Since the end of the last century, a number of new or little-known species within this group have been isolated and reported during faunistic surveys conducted in Chinese coastal areas Ma et al. , 2004Ma et al. , 2006Wang et al. 2008;Miao et al. 2010;Fan et al. 2011a, b). Recent investigations of this class have demonstrated that it is much more diverse than previously assumed (Chantangsi et al. 2013;Liu et al. 2016;Pan H. et al. 2016;Pan X. et al. , 2017Schuster and Bright 2016), which highlights the need to conduct further studies on oligohymenophorean ciliates. ...
The morphology and phylogeny of two poorly known species, Uronema nigricans (Müller, 1786) Florentin, 1901 and Lembadion lucens (Maskell, 1887) Kahl, 1931, were respectively collected from a eutrophic freshwater river in Shenzhen and an oligotrophic lake in Zhanjiang (both in southern China) and investigated using standard taxonomic methods. The sampled population of Uronema nigricans was characterized by a cell size of 30-40 μm × 12-20 μm in vivo, an elongated elliptical outline with a prominent apical plate, and 13-15 somatic kineties. The sampled population of Lembadion lucens was characterized by a cell size of 45-80 μm × 20-50 μm in vivo, 25-35 somatic kineties, five or six caudal kinetosomes with cilia about 20 μm in length, and a single right-positioned contractile vacuole. The small subunit ribosomal RNA gene (SSU rDNA) of these species was sequenced and compared with those of their congeners to reveal nucleotide differences. The phylogenetic trees showed that the Shenzhen population of Uronema nigricans clusters with two other sequences under the name of “Uronema nigricans” (which are possibly misidentified) and then groups with Uronemita sinensis (Pan et al., 2013) Liu et al., 2016 with full support. Phylogenetic analyses indicated that genus Lembadion is monophyletic with full support provided by both Bayesian inference and maximum likelihood algorithms. Based on analyses of morphological and sequence data, Uronemita sinensis may represent a new genus between Uronema and Uronemita.
... According to Lynn 5 , the subclass Scuticociliatia contains three orders: Philasterida, Pleuronematida, and Thigmotrichida. Although Philasterida is a well-outlined lineage, analyses of gene sequences data have challenged the monophyly of both Pleuronematida and Thigmotrichida 63,64 . Indeed as more data have accumulated, the thigmotrichids are often nested within the Pleuronematida, close to the cyclidiids 60,65 . ...
The phylum Ciliophora plays important roles in a wide range of biological studies. However, the evolutionary relationships of many groups remain unclear due to a lack of sufficient molecular data. In this study, molecular dataset was expanded with representatives from 55 orders and all major lineages. The main findings are: (1) 14 classes were recovered including one new class, Protocruziea n. cl.; (2) in addition to the two main branches, Postciliodesmatophora and Intramacronucleata, a third branch, the Mesodiniea, is identified as being basal to the other two subphyla; (3) the newly defined order Discocephalida is revealed to be a sister clade to the euplotids, strongly suggesting the separation of discocephalids from the hypotrichs; (4) the separation of mobilids from the peritrichs is not supported; (5) Loxocephalida is basal to the main scuticociliate assemblage, whereas the thigmotrichs are placed within the order Pleuronematida; (6) the monophyly of classes Phyllopharyngea, Karyorelictea, Armophorea, Prostomatea, Plagiopylea, Colpodea and Heterotrichea are confirmed; (7) ambiguous genera Askenasia, CyclotrichiumParaspathidium and Plagiocampa show close affiliation to the well known plagiopyleans; (8) validity of the subclass Rhynchostomatia is supported, and (9) the systematic positions of Halteriida and Linconophoria remain unresolved and are thus regarded as incertae sedis within Spirotrichea.
... It is a diverse and ubiquitous group and its members have been reported in a wide range of habitats worldwide. The recent descriptions of several novel taxa indicate that the diversity of pleuronematids is underestimated (Fan et al., 2009Fan et al., , 2011a Long et al., 2007; Miao et al., 2010; Wang et al., 2008b). Pleuronema is a speciose genus in the order Pleuronematida , with 28 nominal species having been described. ...
Two novel species, Pleuronema orientale spec. nov. and P. paucisaetosum spec. nov., isolated from coastal waters of Hangzhou Bay, China, were investigated with standard methods. Pleuronema orientale is characterized by: size in vivo 95-135 × 50-85 μm; usually one spherical macronucleus; 12-15 prolonged caudal cilia; two or three preoral kineties and 42-50 somatic kineties; membranelle 1 (M1) about 20% of the anterior fragment of membranelle 2 (M2a) in length, consisting of three longitudinal rows of kinetosomes; posterior end of M2a hook-like; membranelle 3 (M3) three-rowed. Pleronema paucisaetosum is characterized by: size in vivo about 55-85 × 25-55 μm, four or five preoral kineties and 21-23 somatic kineties, posterior end of M2a hooked-like, and M3 three-rowed. The small subunit rRNA gene was sequenced for both species. Phylogenetic analyses reveal that P. orientale is most closely related to P. puytoraci, and that P. paucisaetosum is sister to P. grolierei and P. setigerum (JX310015). With the two new sequences included, the monophyly of the genus Pleuronema is not supported.
... The first two orders include generally free-living and facultatively parasitic species inhabiting various, mainly marine, aquatic environments, whereas Thigmotrichida contains predominantly symbiotic forms parasitizing invertebrates, primarily in the mantle cavity of marine molluscs (Corliss 1979). Recent morphological and molecular investigations have uncovered an unexpectedly high diversity of scuticociliates in marine environments (Miao et al. 2010, Fan et al. 2011, Pan et al. 2013. Consequently, it is reasonable to expect that there is still a large undiscovered diversity of marine scuticociliates. ...
The morphology and taxonomy of two new and two poorly known ciliate species of Ancistrum, found in the mantle cavity (mainly on gills) of marine molluscs from culture beds and pools along the Chinese coast of the Yellow Sea, were investigated using living observation and silver impregnation. Ancistrum haliotis n. sp. was isolated from the abalone Haliotis discus hannai Ino, A. crassum Fenchel, 1965 from the purple clam Saxidomus purpuratus (Sowerby), A. acutum n. sp. from the surf clam Mactra veneriformis Reeve, and A. japonicum Uyemura, 1937 from both the venus clam Cyclina sinensis (Gmelin) and from Dosinia japonica (Reeve). Ancistrum haliotis differs from its most similar relative A. mytili (Quennerstedt, 1867) by the body outline (anterior portion narrower vs. wider than the posterior portion), the macronuclear shape (broadly ellipsoidal vs. reniform or sausage-like), and by having fewer somatic kineties (28–32 vs. usually more than >40). Ancistrum crassum is characterized by the naked area at the apical end of the cell, the relatively short buccal field occupying about two thirds of the body length, and the posterior-dorsal cone-shaped prolongation. Ancistrum acutum n. sp. and A. japonicum are almost identical in morphometry, but differ distinctly in the live morphology (anterior end pointed and posterior end rounded vs. anterior end narrowly rounded and posterior-dorsal end protruded) and ciliary pattern (all right-side kineties extend to posterior body end vs. all right-side kineties excluding somatic kinety 1 distinctly shortened posteriad, forming a glabrous zone). We neotypify Ancistrum japonicum and discuss the taxonomic status of the four species. Based on an evaluation of all nominal species of Ancistrum and Ancistrumina, we recognize nine valid species of Ancistrum and provide a tabular guide to their identification. Fenchelia Raabe, 1970 is regarded as a junior synonym of Ancistrum Maupas, 1883. We synonymize Ancistrumina nucellae Khan, 1970 with Ancistrum japonicum Uyemura, 1937 and Ancistrum edajimanum Oishi, 1978 with A. crassum Fenchel, 1965.
... We provide 26 new sequences from six genera, including the molecular data from the genera Falcicyclidium, Cristigera and Protocyclidium (Fig. 1). As previous phylogenetic analyses of pleuronematids and thigmotrichids were based on only SSU-rDNA (Gao et al., 2010;Miao et al., 2010;Yi et al., 2009), our focus is phylogenetic analyses based on single genes as well as concatenated data to understand better the phylogenetic relationship of the pleuronematids and thigmotrichids, especially the problematic cyclidiids. The secondary structures of the variable region 4 of the small subunit ribosomal RNA (SSU-rRNA) of cyclidiids and thigmotrichids are also predicted and compared to give a better understanding of the relationships among cyclidiids and thigmotrichids. ...
Cyclidiids and thigmotrichids are two diverse groups of scuticociliates, a diverse clade of ciliates that is often difficult to investigate due to the small size and conserved morphology among its members. Compared to other groups (e.g. hypotrichs and oligotrichs), the scuticociliates have received relatively little attention and their phylogenetic relationships are largely unresolved. To contribute to our understanding of their evolutionary history, we characterized 26 sequences for three linked genes (SSU-rDNA, 5.8S and LSU-rDNA) from 14 isolates of cyclidiids and thigmotrichids. Phylogenetic analyses reveal the following: 1) traditional cyclidiids are associated with thigmotrichs rather than pleuronematids as expected; 2) the validity of the newly-reported genus Falcicyclidium is confirmed by the molecular data and we suggest to transfer this genus to the family Ctedoctematidae; 3) both the genera Cyclidium and Protocyclidium are not monophyletic and the separation of Protocyclidium from Cyclidium is not supported; 4) the genus Cristigera is a well supported monophyletic group and may stand for a new family; 5) according to both morphological and molecular information, Cyclidium plouneouri Dragesco, 1963 should be assigned in the genus Falcicyclidium and thus a new combination is suggested: Falcicyclidium plouneouri (Dragesco, 1963) n. comb.; and 6) based on the data available, a new genus is suggested: Acucyclidium gen. nov. with the type species, Acucyclidium atractodes (Fan et al., 2011) n. comb.
