Search

In photoperiod-sensitive plants, the CO-like gene (CONSTANS-like, COL) has a crucial function in regulating the timing of flowering. The blooming period in foxtail millet is greatly influenced by the duration of daylight; however, there is a scarcity of data regarding the molecular properties of the COL genes in the foxtail millet. In this study, we conducted a comprehensive analysis of the COL gene family in foxtail millet at the genome-wide level. We identified 11 SiCOL genes and performed gene structure analysis, which showed pronounced variation in gene length and intron number among the genes. The examination of COL proteins in foxtail millet and other plant species using phylogenetic analysis revealed that they could be clustered into three distinct groups. Cis-element analysis identified elements related to light-responsiveness, hormones, and abiotic stress in the promoter region of the SiCOL gene. Furthermore, tissue-specific expression analysis showed widespread expression of all 11 SiCOL genes in various foxtail millet tissues and organs, particularly in leaves and panicles. Collinearity analysis identified 14 syntenic gene pairs in both foxtail millet and rice. The results also revealed diurnal oscillations in the transcription levels of SiCOL genes under different light conditions. Moreover, among the 11 genes, SiCO, SiCOL1, and SiCOL6 expression levels were negatively correlated with flowering time variation in two foxtail cultivars. Additionally, upon constructing a network of predicted molecular interactions, FLOWER LOCUS-like (FTL) and Phytochromea A (PHY A) were suggested to potentially interact with SiCO, SiCOL1, and SiCOL6. SiCO, SiCOL1, and SiCOL6 have the potential for flowering and heading in foxtail millet. This research enhances our comprehension of the role and control of the SiCOL gene family constituents in foxtail millet, establishing a basis for future investigations., (© 2024. The Author(s).)

The utility of the mitochondrial genomes (mitogenomes) in analyzing the evolutionary history of animals has been proven. Five deep-sea corals ( Bathypathes sp.1, Bathypathes sp.2, Schizopathidae 1, Trissopathes sp., and Leiopathes sp.) were collected in the South China Sea (SCS). Initially, the structures and collinearity of the five deep-sea coral mitogenomes were analyzed. The gene arrangements in the five deep-sea coral mitogenomes were similar to those in the order Antipatharia, which evidenced their conservation throughout evolutionary history. Additionally, to elucidate the slow evolutionary rates in Hexacorallia mitogenomes, we conducted comprehensive analyses, including examining phylogenetic relationships, performing average nucleotide identity (ANI) analysis, and assessing GC-skew dissimilarity combining five deep-sea coral mitogenomes and 522 reference Hexacorallia mitogenomes. Phylogenetic analysis using 13 conserved proteins revealed that species clustered together at the order level, and they exhibited interspersed distributions at the family level. The ANI results revealed that species had significant similarities (identity > 85%) within the same order, while species from different orders showed notable differences (identity < 80%). The investigation of the Hexacorallia mitogenomes also highlighted that the GC-skew dissimilarity was highly significant at the order level, but not as pronounced at the family level. These results might be attributed to the slow evolution rate of Hexacorallia mitogenomes and provide evidence of mitogenomic diversity. Furthermore, divergence time analysis revealed older divergence times assessed via mitogenomes compared with nuclear data, shedding light on significant evolutionary events shaping distinct orders within Hexacorallia corals. Those findings provide new insights into understanding the slow evolutionary rates of deep-sea corals in all lineages of Hexacorallia using their mitogenomes., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

The morphology and morphogenesis of Lamtostyla paravitiphila nov. spec., a novel soil hypotrichous ciliate collected from eastern China, were investigated based on live observations and protargol-stained specimens. The new species is morphologically characterized as follows: seven to twelve macronuclear nodules, cortical granules absent, 19-26 adoral membranelles, three or four frontoventral cirri, the amphisiellid median cirral row extends to about mid-body and composed of 12-18 cirri, two or three transverse cirri, 27-39 left and 30-41 right marginal cirri, three almost bipolar dorsal kineties. Morphogenetically, it is characterized by the initial formation of six frontal-ventral-transverse cirral anlagen as primary primordia. Notably, the amphisiellid median cirral row and the posterior frontoventral cirrus (or cirri) contribute to the development of the frontal-ventral-transverse cirral anlagen, while the buccal cirrus may not participate in this process. Phylogenetic analyses based on small subunit ribosomal DNA sequence data indicate that the Lamtostyla species with available molecular data do not form a monophyletic group., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

The morphology, morphogenesis and molecular phylogeny of a new saline soil hypotrich ciliate, Uroleptoides salina nov. spec., discovered from China, was investigated. The new species is characterized as follows: body 150-215 × 40-50 μm in vivo, slender and highly flexible; usually four ellipsoidal macronuclear nodules; contractile vacuole absent; cortical granules absent; endosymbiotic algae present; amphisiellid median cirral row consists of 14-25 cirri and terminates about 47% down length of body; usually three buccal cirri and 3-13 cirri left of anterior portion of amphisiellid median cirral row; 3-5 transverse cirri. Morphogenesis during binary fission is characterized by: (1) the parental adoral zone of membranelles is retained completely, parental paroral contributes to the formation of the undulating membranes anlage for the proter; (2) the oral primordium of the opisthe is formed apokinetally; and (3) the amphisiellid median cirral row is formed from two anlagen. Phylogenetic analyses based on SSU rDNA sequence data show that Uroleptoides salina nov. spec. has a close relationship with its morphologically similar species, U. longiseries, U. magnigranulosus, Orthamphisiella breviseries, and Parabistichella variabilis., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

The classification of hypotrichs based on the gonostomatid oral structure is widely accepted, but the phylogenetic signal of this character is unknown. Here, we infer the species phylogeny of those gonostomatids for which molecular data are available, plus 26 new sequences of SSU-rDNA, ITS1-5.8S-ITS2 and LSU-rDNA genes. The results indicate that: (i) the endoral is more phylogenetically informative than the paroral; (ii) the structure of the endoral and the Gonostomum-pattern adoral zone of membranelles are plesiomorphies for the hypotrichs sensu stricto; (iii) the group of species possessing these features is monophyletic in all our phylogenetic analyses, except that for the SSU-rDNA; (iv) Schmidingerotrichidae is monophyletic in all trees, suggesting that it is a well-defined family; (v) the Gonostomatidae is polyphyletic in the SSU-rDNA and ITS1-5.8S-ITS2 trees, with Gonostomum, Cladotricha, Cotterillia, Metagonostomum, Paragonostomum and Wallackia distributed among separate clades, but monophyletic in the LSU-rDNA and concatenated trees; (vi) higher hypotrich taxa such as core urostyloids and core sporadotrichids/stichotrichids might have evolved from species that possessed a gonostomatid oral apparatus.

A soil hypotrich ciliate, Afrokahliella paramacrostoma n. sp., was discovered in China. Its morphology, morphogenesis and molecular phylogeny were investigated using standard methods. The new species is characterized as follows: body about 140-180 × 60-70 μm in vivo, cortical granules absent, contractile vacuole positioned about 40% down length of body, 5-9 macronuclear nodules, 34-49 adoral membranelles, 3-5 buccal and 3-6 parabuccal cirri, usually two frontoventral rows, three or four left and two or three right marginal rows, three dorsal kineties and one dorsomarginal kinety; 1-3 and one or two caudal cirri located at the ends of dorsal kineties 1 and 2, respectively. The ontogenetic process is characterized by: (1) the marginal anlagen on each side develop in the outer right and the inner left marginal rows, respectively; (2) five frontoventral-transverse cirral anlagen, anlagen II-IV develop in secondary mode; (3) dorsal morphogenesis follows a typical Urosomoida-pattern, no parental dorsal kineties are retained; (4) caudal cirri are generated at the ends of dorsal kineties 1 and 2. Phylogenetic analyses based on SSU rDNA sequence data reveals that Afrokahliella paramacrostoma n. sp. is closely related to Parakahliella macrostoma and Hemiurosomoida longa., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

The living morphology, infraciliature, morphogenesis and phylogenetic position of a new hypotrichous ciliate, Heterourosomoida sinica n. sp., discovered in saline soil in Northwest of China, were investigated. Heterourosomoida sinica n. sp. is characterized as follows: body size about 70-95 × 20-30 μm in vivo, ellipsoid or elongate; cortical granules dark green, 0.5 μm across, arranged around dorsal cilia and in short irregular rows on ventral side; consistently 18 frontoventral-transverse cirri; left and right marginal rows composed of 17-24 and 13-21 cirri, respectively; two macronuclear nodules and one or two micronuclei. The detailed morphogenesis of a species of Heterourosomoida is reported for the first time. The ontogenesis on dorsal side is basically similar to that in Urosomoida-species and the process on ventral side is characterized by: 18 frontoventral-transverse cirri develop from six anlagen with the anlagen V and VI formed in the primary mode. Phylogenetic analyses based on SSU rDNA sequence data reveal that Heterourosomoida sinica n. sp. clusters with Kleinstyla dorsicirrata and forms a clade with the type species H. lanceolata., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Morphogenesis of the soil hypotrich ciliate, Holostichides chardezi Foissner, 1987, collected from southeastern China, was investigated using the protargol staining method. The main morphogenetic events follow a similar process with that of its congeners. Phylogenetic analyses based on the SSU rDNA sequence data indicate that Holostichides is nonmonophyletic; H. chardezi, the type species of Holostichides, clusters with H. heterotypicus, while H. terrae is distinctly separate from these species. H. terrae can be distinguished from H. chardezi (type species of Holostichides) and H. heterotypicus by undulating membranes relatively long and distinctly curved (vs. relatively short and straight), pharynx with (vs. without) rod-shaped structure, and two (vs. more than two) frontoterminal cirri. Therefore, a new genus, Anteholostichides nov. gen., has been proposed for H. terrae. Further, the diagnosis of the genus Holostichides is improved., (© 2019 International Society of Protistologists.)

The morphology, morphogenesis and molecular phylogeny of the oxytrichid ciliate, Monomicrocaryon euglenivorum euglenivorum (Kahl, 1932) Foissner, 2016, isolated from freshwater in a seaside park, Guangzhou, China, were investigated. Monomicrocaryon euglenivorum euglenivorum can be recognized as follows: caudal cirri in midline of body; dorsal kinety 1 without a one-kinetid-wide gap; transverse cirri acicular or rod-shaped with a fringed distal end; right marginal row commences at level of buccal vertex or anterior to buccal vertex. The main events during binary fission are as follows: (1) the proter retains the parental adoral zone of membranelles entirely; (2) frontoventral-transverse cirral anlagen I-VI are segmented in the ordinary pattern 1:3:3:3:4:4 from left to right, which form three frontal, four frontoventral, one buccal, three postoral ventral, two pretransverse ventral and five transverse cirri, respectively; (3) dorsal morphogenesis is in the typical Oxytricha-pattern, but fragmentation of dorsal kinety 3 is indistinct; and (4) three caudal cirri are formed, one at the posterior end of each of dorsal kineties 1, 2 and 4. Phylogenetic analyses based on SSU rDNA sequences showed that M. euglenivorum euglenivorum clustered with Kleinstyla dorsicirrata and Heterourosomoida lanceolata rather than with its congener M. elegans. The genus Monomicrocaryon is not monophyletic in this study; however, its monophyly is not rejected by the AU test., (Crown Copyright © 2019. Published by Elsevier GmbH. All rights reserved.)

Morphogenesis of the hypotrich ciliate Uroleptoides longiseries, isolated from sandy soil beside the Yellow River, Suide, Yulin, Shaanxi Province, China, was investigated using protargol staining. The main events during binary fission are as follows: (1) the long frontoventral row is formed by a single anlage; (2) five frontoventral-transverse cirral anlagen are formed in primary mode; (3) only the posterior part of the parental adoral zone of the membranelles is renewed; and (4) the oral primordium of the opisthe is formed intrakinetally. This is the first detailed record of all stages of morphogenesis for Uroleptoides. We also provide the first record of the small subunit ribosomal DNA (SSU rDNA) sequences for U. longiseries. Phylogenetic analyses based on the SSU rDNA sequences data show that Uroleptoides longiseries clusters with U. magnigranulosa with moderate to high support which together form a clade with Orthoamphisiella breviseries. These three species share the morphogenetic feature of the long frontoventral row being formed by a single anlage., (© 2018 International Society of Protistologists.)

Ciliates are one of the eukaryotic unicellular organisms which are thought to be the oldest life forms, and widely geographically distributed. For a variety of reasons, some groups of ciliates have attracted more attention than others, such as the class Spirotrichea and related species with its complicated evolutionary relationships. In this study, we obtained the transcriptome data of three typical ciliates, Uroleptopsis citrina, Euplotes vannus, Protocruzia tuzeti using high throughput sequencing. The genetic relationships were revealed by phylogenomic analysis of 109 genes comprising of 34,882 amino acid residues, and analyses based on SSU rDNA of 55 species, as well as the comparison of gene content among spirotricheans and related species. Our phylogenomic analyses show the Spirotrichea is monophyletic when Protocruzia is excluded, in which four subclasses: Oligotrichia, Choreotrichia, Hypotrichia and Euplotia also formed momophyletic groups respectively. The Hypotrichia was placed as a sister branch to the assemblage, in which two oligotrichs clustered with two choreotrichs. In addition to this, the Protocruziidia was placed in an independent lineage status out of the Spirotrichea. Together with its high binding-related gene content compared to other species and the significant variation in morphological characters, these findings support the removal of Protocruzia from the class Spirotrichea., (Copyright © 2018. Published by Elsevier Inc.)

The morphology, morphogenesis and small subunit (SSU) rRNA gene-based phylogeny of Neourostylopsis flava paraflava nov. subsp. were investigated. Neourostylopsis flava paraflava nov. subsp. was separated from N. flava flava nov. stat. by habitat (brackish water vs. fresh water), pretransverse cirri (absent in all specimens vs. present in 15% of specimens), the numbers of frontal cirri (8-15 vs. 6-8) and left marginal cirral rows (6-9 vs. 4-5). The main morphogenetic features of N. flava paraflava nov. subsp. are as follows: (1) streaks I-VI (or I-VIII, deduced from morphological data) produce the bicorona; (2) the oral primordium and frontoventral-transverse cirral anlagen in the opisthe are formed de novo on the cell surface; (3) the numerous macronuclear nodules fuse into a branch-like mass; (4) two pretransverse ventral cirri are formed initially but disappear in the later stages; and (5) some of the frontoventral-transverse cirral anlagen develop in a primary mode. Based on SSU rDNA sequence data, phylogenetic analyses show a close relationship between N. flava paraflava nov. subsp., N. flava flava nov. stat. and other Neourostylopsis species. An improved diagnosis for Neourostylopsis is provided: Urostylidae with five or more frontal cirri which form an indistinct or distinct bicorona; pretransverse cirri present or absent; transverse cirri present; buccal cirri present; two frontoterminal cirri; midventral complex composed of midventral pairs only; more than one row of marginal cirri on each side which derive from individual anlagen within each parental row; caudal cirri lacking; three dorsal kineties; endoral and paroral rather long, endoral straight, paroral distinctly curved anteriorly., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

The living morphology, infraciliature and morphogenetic events of a new soil urostylid ciliate, Australothrix xianiensis nov. spec., collected from Chanba National Wetland Park in Xi'an, China, were studied in vivo and after protargol preparation. Australothrix xianiensis nov. spec. is characterized as follows: about 190-240 × 40-60 μm in life; body pisciform and dark; cortical granules arranged in longitudinal rows on both sides, colourless, rod-shaped and about 2 × 1 μm in size; single contractile vacuole slightly ahead of mid-body with two long collecting canals; macronuclear nodules scattered throughout cytoplasm; adoral zone occupies about 20% of body length, composed of about 32 membranelles; three frontal cirri and one buccal cirrus; two to four midventral pairs and four or five midventral rows, one left and two right marginal rows; four or five dorsal kineties; four or five caudal cirri. The main features of divisional morphogenesis are: (1) each posterior streak generates a midventral row together with the midventral pair; (2) the old adoral zone of membranelles is retained with the exception of the posterior part, which is renewed in situ; the undulating membranes are completely renewed; (3) parental cirri do not contribute to the construction of the oral primordium in the opisthe in very early dividers; (4) two sets of frontoventral cirral anlagen are formed., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

The hypotrich Schmidingerothrix elongata spec. nov., discovered in saline (20‰) soil of the Longfeng Wetland, Daqing, northern China, was studied using live observation and protargol impregnation. It is characterized, inter alia, by colorless cortical granules arranged in short rows, three frontoventral cirral rows with the rightmost extending far posteriorly, and 4-8, usually six macronuclear nodules. Cell division proceeds as in congeners and confirms the lack of dorsal ciliature. In phylogenetic analyses based on SSU rDNA, S. elongata is sister of S. salinarum+Paracladotricha salina. A re-investigation of the type slides of P. salina, type of Paracladotricha, revealed a misobservation in the original description. Since P. salina lacks, like Schmidingerothrix spp., a dorsal ciliature, Paracladotricha becomes a junior, subjective synonym of Schmidingerothrix with S. salina comb. nov. as fourth species. A review of the phylogenetic analyses dealing with Schmidingerothrix shows that its position is variable. However, together with the gonostomatid oral apparatus it can be hypothesized that Schmidingerothrix is a member of the Gonostomatidae or a close relative. A list of genera (14) and species (58) which have - like Schmidingerothrix - a gonostomatid oral apparatus, as well as a key to these genera are provided., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

A hypotrichous ciliate, Paragonostomoides xianicum n. sp., was discovered in soil on the surface of the Xi'an Circumvallation, Xi'an, China. Its morphology and some major ontogenetic stages were studied and the phylogenetic position was estimated using standard methods Paragonostomoides xianicum n. sp. is characterized as follows: body size about 75-90×15-25μm in vivo, elliptical and flexible; colourless mitochondrion-like cortical granules scattered throughout cell surface, about 0.8×0.6μm in size; contractile vacuole positioned at mid-body; frontoventral row IV extends beyond buccal vertex and frontoventral row VI extends to about body end; frontoventral cirri not in pairs; transverse cirri absent; three caudal cirri; two macronuclear nodules and one to four micronuclei. The ontogenetic process in P. xianicum n. sp. is basically similar to that in Metagonostomum gonostomoidum and Gonostomum-species and featured by: frontoventral-transverse cirri develop in five-anlage pattern, the rearmost cirri generated in the two rightmost FV anlagen are not set off posteriorly (like an ordinary TC), as well as FVT-anlagen n and n-1 form in secondary mode in P. xianicum. Phylogenetic analyses based on small subunit ribosomal DNA sequence data reveal a close relationship of P. xianicum n. sp. with Cotterillia bromelicola and two Gonostomum-species., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

Morphogenesis in a population of Urosoma salmastra collected from saline soil in Weinan, China, was investigated using protargol staining. The main morphogenetic event that characterizes U. salmastra is the inclusion of cirrus III/2 in the formation of the frontoventra-transverse cirral anlagen. We also provide small subunit ribosomal DNA gene sequences for a population of U. salmastra and for two populations of U. emarginata. The molecular phylogeny indicates that Urosoma is not monophyletic, viz, U. emarginata branches separately from its congeners and the closest relative of U. salmastra is Oxytricha granulifera., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

Morphogenesis in the soil hypotrich ciliate, Rigidohymena quadrinucleata (Dragesco and Njine, 1971) Berger, 2011; was investigated using protargol staining. The main events during binary fission are as follows: (1) the proter retains the parental adoral zone of membranelles entirely, whereas the old undulating membranes dedifferentiate into an anlage that gives rise to the leftmost frontal cirrus and the new undulating membranes of the proter; (2) six streaks of frontoventral-transverse cirral anlagen are segmented in the pattern 1:3:3:3:4:4 from left to right, which form three frontal, four frontoventral, one buccal, five ventral and five transverse cirri, respectively; (3) the postoral ventral cirrus V/3 is not involved in primordia formation demonstrating that this species belongs to the stylonychines; (4) marginal anlagen are formed intrakinetally and the right marginal anlagen develop much earlier than the left ones; (5) the generation of the dorsal kineties is of typical Oxytricha-pattern and three caudal cirri are formed, one at the posterior end of each of dorsal kineties 1, 2 and 4. Phylogenetic analyses based on SSU rDNA sequence data indicate that Rigidohymena is polyphyletic and that R. quadrinucleata clusters with R. candens with full support., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

The morphology, morphogenesis, and SSU rDNA sequence of a Caudiholosticha stueberi population from Southwest China soil were analyzed. The studies confirm the assumption of previous workers that this species has dorsomarginal kineties and thus does not belong to the urostyloids, but to the non-oxytrichid dorsomarginalian genus Uroleptus whose members have, in contrast to C. stueberi, a distinct tail. On the basis of two morphological features we split Uroleptus into three subgenera: U. (Uroleptus) (tail present; more than five transverse cirri; habitat freshwater), U. (Paruroleptus) (present; five or less; freshwater or soil), and U. (Caudiholosticha) stat. nov. (lacking; five or less; soil). Since Uroleptus (Caudiholosticha) stueberi comb. nov. is the type of Caudiholosticha, the other 16 species so far assigned to Caudiholosticha have to be reclassified because they obviously lack dorsomarginal kineties. Based on published data, six new urostyloid genera are established: Extraholosticha gen. nov. (type: Holosticha sylvatica; monotypic); Adumbratosticha gen. nov. (type: H. tetracirrata; three species); Acuholosticha gen. nov. (type: U. paranotabilis; five species); Limnoholosticha gen. nov. (type: H. (Holosticha) navicularum; four species); Multiholosticha gen. nov. (type: H. multicaudicirrus; two species); and Caudikeronopsis gen. nov. (type: Caudiholosticha marina; monotypic). Urosomoida sejongensis is transferred to Oxytrichella: O. sejongensis comb. nov., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

The living morphology, infraciliature and morphogenesis of a new ciliate, Urosomoida paragiliformis n. sp., collected from saline soil in Weinan, China, were studied in vivo and after protargol staining. Urosomoida paragiliformis n. sp. is characterized as follows: body elongate-elliptical with no tail, flexible and slightly contractile; cortical granules dark-brown, 0.5μm across, arranged in short irregular rows; about 33 adoral membranelles; 14 frontoventral-transverse cirri; right and left marginal rows not confluent posteriorly; two macronuclear nodules. Morphogenesis of U. paragiliformis n. sp. corresponds well with that of other Urosomoida-species except that in reorganisers the oral primordium develops membranelles that replace those at the proximal end of the old adoral zone, whereas in dividers the entire parental adoral zone of membranelles is inherited by the proter. Phylogenetic analyses based on SSU rDNA sequence data suggest a close relationship between U. paragiliformis n. sp. and Paraurosomoida indiensis. A new combination is made: Oxytrichella subtropica (Fan et al., 2015) comb. nov. (basionym Urosomoida subtropica)., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

The morphology and morphogenesis of a new saline soil hypotrich, Lamtostyla salina n. sp., collected from Longfeng Wetland in Daqing, north China, were studied based on live observations and protargol stained specimens. The new species is characterized as follows: body very flexible but not contractile, lanceolate with anterior end broadly rounded, widest at about 1/3 of body length, posterior end narrowly rounded; cortical granules colourless and scattered; amphisiellid median cirral row ends ahead of mid-body, composed of 5-13 cirri; 4-20 frontoventral cirri arranged in 2-4 rows; three frontal, one buccal and 2-6 transverse cirri; usually one left and one right marginal row, composed of 17-51 and 20-51 cirri respectively; usually two dorsal kineties; two macronuclear nodules and two micronuclei. Morphogenesis is typical of the genus Lamtostyla: parental structures are involved in the formation of frontoventral transverse anlagen in the proter. Phylogenetic analyses based on small subunit ribosomal DNA sequence data reveal that the systematic position of Lamtostyla is rather unstable with low support values across the tree. However, a well-recognized close relationship between Lamtostyla and Bistichella are shown in all phylogenetic analyses., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Traditionally classifications of the Urostyloida have been mainly based on morphology and morphogenesis. Recent molecular phylogenetic analyses have been largely based on single-gene data for a limited number of taxa. Consequently, incongruence has arisen between the morphological/morphogenetic and the molecular data. In this study, the three phylogenetic markers (SSU rDNA, ITS1-5.8S-ITS2 region, and LSU-rDNA) of three urostyloid genera represented by four species (Bakuella granulifera, Anteholosticha monilata, Caudiholosticha sylvatica, and C. tetracirra) were sequenced to investigate their phylogeny. The results show that: (1) all three genera should be regarded as the members of the order Urostyloida within the subclass Hypotrichia, as indicated by morphological characters; (2) phylogenetic analyses and sequence similarities both indicate that neither Anteholosticha nor Caudiholosticha are monophyletic and the systematic assignment of both genera awaits further evaluation; and (3) Bakuella has a closer relationship with Urostyla than with bakuellids (e.g. Apobakuella and Metaurostylopsis), suggesting Bakuella may belong to the family Urostylidae rather than the family Bakuellidae., (© 2014 The Author(s) Journal of Eukaryotic Microbiology © 2014 International Society of Protistologists.)

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., (Copyright © 2014 Elsevier GmbH. All rights reserved.)

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., (© 2014 IUMS.)

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., (Copyright © 2014 Elsevier GmbH. All rights reserved.)

The morphology and infraciliature of two hypotrichous ciliates, Urosoma salmastra and U. karinae sinense nov. sspec., were investigated for populations collected from the surface of intertidal gravel in the Huguang Mangrove Forest, Zhanjiang, China and the upper 10cm layer of soil in the Sangke Grass Land in the southern part of Gansu Province, China, respectively. Urosoma salmastra is characterized by its elongate-elliptical body with no tail-like structure; two macronuclear nodules; cortical granules colourless, less than 1μm across, and arranged in short rows; adoral zone occupying 25% of body length in vivo; paroral conspicuously short and located in front of endoral. Urosoma karinae sinense nov. sspec. is characterized by its elongate-elliptical body with no tail; 2-4 macronuclear nodules; cortical granules colourless, less than 1μm across, and arranged in short rows; adoral zone occupying 30% of body length in vivo; paroral shorter than, and located ahead of endoral. Phylogenetic analyses based on SSU rRNA gene sequence data suggest a close relationship between U. salmastra, U. karinae sinense nov. sspec. and Oxytricha granulifera within the Oxytrichinae assemblage., (Copyright © 2014 Elsevier GmbH. All rights reserved.)

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., (© 2014 IUMS.)

This paper investigates the morphology, morphogenesis and SSU rRNA gene-based phylogeny of Apoholosticha sinica n. g., n. sp., isolated from mangrove wetland in Shenzhen, southern China. The new genus Apoholosticha is characterized by its bipartite adoral zone, clearly differentiated frontal cirri arranged in a bicorona, midventral complex composed of midventral pairs only, one marginal cirral row on each side, presence of frontoterminal and transverse cirri, and the lack of a buccal cirrus and caudal cirri. The type species, Apoholosticha sinica n. sp. is diagnosed by the elongated body shape and two kinds of cortical granules. Its main morphogenetic features are similar to that of Pseudokeronopsis except for (1) no buccal cirrus is formed and (2) its macronuclear nodules fuse into a single mass during cell division. Phylogenetic analyses for the new taxon indicate that Apoholosticha n. g. is most closely related to Nothoholosticha and Heterokeronopsis, and falls into the family Pseudokeronopsidae within the core Urostylida clade. In addition, a species that had been misidentified in previous literature is here recognized and assigned to the new genus as Apoholosticha sepetibensis (Wanick and Silva-Neto, 2004) n. comb. (basionym: Pseudokeronopsis sepetibensis Wanick and Silva-Neto, 2004)., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Two new species of the taxonomically confused genus Amphisiella were isolated from brackish-water habitats in southern China, and their morphology and morphogenesis were investigated. The genes coding for small subunit (SSU) rRNA were sequenced in each species and included in a phylogenetic analysis with all data available from nominal species of Amphisiella and related hypotrichs. Both new species are diagnosed by an elongate body shape, yellow-brown/grey-brown cell color, one kind of cortical granule, and two macronuclear nodules. The cortical granules in A. pulchra sp. n. are grouped in small clusters which are irregularly distributed both ventrally and dorsally; in A. candida sp. n., they are irregularly and sparsely distributed ventrally and form longitudinal stripes dorsally. The ontogenetic processes of both species show similarities to those of other congeners. Phylogenetic trees based on SSU rRNA gene sequences suggest that the family Amphisiellidae is a paraphyletic assemblage. The results further demonstrate that two isolates identified as Amphisiella annulata (DQ832260 and GU170843) are very likely cryptic species, and a sequence identified as A. milnei (DQ845293) may belong to a genus other than Amphisiella., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

A novel stichotrich ciliate, Strongylidium orientale sp. nov., was discovered from a mangrove river in Hong Kong, southern China, and its morphology was investigated through observations in vivo and after protargol impregnation. Cells are 80-120 × 35-50 µm in vivo and fusiform in shape, with rounded anterior and tapered posterior ends. It is characterized by its brackish habitat and by the presence of two types of cortical granules arranged irregularly throughout the cortex. Morphogenetic events of cell division and physiological reorganization are described. The main ontogenetic features were: (i) only the posterior portion of the parental adoral zone of membranelles was renewed by dedifferentiation of the old structures; (ii) the oral primordium in the opisthe occurred apokinetally; (iii) the left and right ventral rows originated intrakinetally and the final left ventral row was spliced from two cirri from the frontoventral cirral anlage, a short cirral row from the anlage for the right ventral row and a long cirral row which was formed from the whole anlage of the left ventral row; (iv) the marginal rows developed intrakinetally; (v) the dorsal kineties replicated entirely de novo and did not fragment; and (vi) the two macronuclear nodules fused into a mass and then divided. Based on small-subunit rRNA gene sequences, phylogenetic analyses showed a close relationship with its congener Strongylidium pseudocrassum and with the genus Pseudouroleptus.

This paper investigates the morphology, infraciliature and small-subunit (SSU) rRNA gene sequences of two hypotrichous ciliates, Neourostylopsis orientalis n. sp., and Protogastrostyla sterkii (Wallengren, 1900) n. comb. (basionym Gastrostyla sterkii), collected from coastal waters in southern China. Neourostylopsis orientalis n. sp. is diagnosed mainly by the arrangement of brownish cortical granules, the numbers of adoral membranelles and frontal and transverse cirri and the characteristics of its midventral cirral pairs. The SSU rRNA gene phylogeny strongly supports the establishment of the new genus Neourostylopsis n. gen., which is characterized mainly by the following features: frontal and transverse cirri clearly differentiated, buccal cirri present, two frontoterminal cirri, midventral complex composed of midventral pairs only and not exceeding the halfway point of the cell, more than one row of marginal cirri on each side which derive from individual anlagen within each parental row, caudal cirri lacking. Thus, two new combinations are required: Neourostylopsis songi (Lei et al., 2005) n. comb., and Neourostylopsis flavicana (Wang et al., 2011) n. comb. Additionally, improved diagnoses for both Metaurostylopsis and Apourostylopsis are supplied in this study. Protogastrostyla sterkii (Wallengren, 1900) n. comb. differs from the similar congener Protogastrostyla pulchra mainly in body shape, ratio of buccal field to body length in vivo and molecular data. Based on the present studies, we conclude that the estuarine population of P. pulchra collected by J. Gong and others [Gong et al., J Eukaryot Microbiol (2007) 54, 468-478] is a population of P. sterkii.

A marine hypotrich ciliate, Heterotachysoma multinucleatum (Gong and Choi, 2007) n. comb., found in coastal waters near Qingdao, China, was investigated. Heterotachysoma multinucleatum is characterized by its dorsal ciliature arranged in Gonostomum-pattern. Additionally, a new genus, Heterotachysoma n. gen., is established which is mainly characterized by: 18-cirri pattern; flexible body; three dorsal kineties with no dorsomarginal kineties nor kinety fragmentation; one right and one left row of marginal cirri; caudal cirri absent. The genus Tachysoma is redefined, and three new combinations, T. multinucleatum, T. ovatum and T. dragescoi, are proposed. The morphogenesis of Hemigastrostyla enigmatica (Dragesco and Dragesco-Kernéis, 1986) Song and Wilbert, 1997, is also described. Compared with that of its congeners, the differences are mainly in the dorsal ciliature: (1) the dorsal kinety anlagen are formed de novo in H. enigmatica (vs. intrakinetally in H. paraenigmatica and H. elongata); (2) the dorsal kineties anlagen develop in secondary mode in H. enigmatica (vs. primary mode in H. paraenigmatica); (3) the kinetal fragment anterior to the right marginal row in both filial product is absent in both H. enigmatica and H. elongata (vs. present in H. paraenigmatica). These findings suggest that morphogenesis is not uniform among members of the genus Hemigastrostyla., (Crown Copyright © 2012. Published by Elsevier GmbH. All rights reserved.)

The morphology, ontogeny and molecular phylogeny of Apobakuella fusca gen. n., sp. n. and Parabistichella variabilis gen. n., sp. n., from south China were investigated. Apobakuella fusca, brown colored, demonstrates bakuellid-like infraciliature, and a similar ontogenesis as the genus Bakuella. It is argued, however, that this species represents a novel genus, Apobakuella, which is characterized by two or more marginal rows on the right, several buccal and parabuccal cirri, and lack of frontoterminal and caudal cirri. Phylogenetic analysis based on SSU rRNA gene sequences supports the close relationship of Apobakuella with Neobakuella and Diaxonella within the core Urostylida. By contrast, Parabistichella variabilis has a dominant frontoventral row, few midventral pairs, a long midventral row, and one marginal row on each side. Its morphogenesis exhibits: (1) partial reorganization of the parental adoral membranelles; (2) over six frontoventral-transverse cirri anlagen; (3) intrakinetal development of the midventral row; and (4) very likely, formation of the frontoventral row from the midventral row anlage. Both the morphological characteristics and the SSU rRNA gene sequences suggest that it is incertae sedis among the basal hypotrichs. Further investigation of key taxa with additional molecular markers is required to reveal a better understanding on the phylogeny of Parabistichella., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

During faunistic studies on psammophilic ciliates along the coast of Qingdao, China, a population of the poorly known species Parasonderia vestita (Kahl, 1928) comb. nov. (basionym: Plagiopyla vestitaKahl, 1928) was found and investigated using silver staining methods. These revealed that its oral ciliature is rather unique and composed of polykinetids comprising four parts: prebuccal polykineties, postbuccal polykineties, parabuccal polykineties, and intrabuccal polykineties. Both the pre- and the postbuccal polykineties are, as extensions of the somatic kineties, spiraling and extending from cell surface into buccal cavity. The somatic kineties are composed mainly of dikinetids with some monokinetids and trikinetids inserted. They are separated into two types: four circle kineties and 24-28 bipolar kineties. The circle kineties start from the side of oral region and connect with the opposite section at the end of the body. Phylogenetic analysis based on SSU rRNA gene sequence data indicates that P. vestita falls into the core part of the order Plagiopylida and groups with an environmental sequence with high support and forms a sister clade with Lechriopyla mystax, Plagiopyla frontata and P. nasuta., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

Discocephalids and pseudoamphisiellids are possibly two of the most confused groups among hypotrichous/euplotid ciliates regarding their systematic position and phylogenetic relationships. The former were often regarded as related to euplotids while the latter, in the absence of molecular data, were mostly assigned to the urostylid-like hypotrichs. In the present work, the small subunit rRNA genes of several rarely observed discocephalid and pseudoamphisiellid genera were analyzed to obtain insights into the phylogenetic relationships of these highly ambiguous Spirotrichea. Four different tree reconstruction algorithms yielded nearly identical topologies, which indicated both groups belong to the same assemblage. This assemblage is clearly isolated as a deep-branching clade and invariably positioned between Euplotida and Hypotricha. The sister group relationship of the Pseudoamphisiellidae and Discocephalidae supports the previous suggestion that they might represent an ordinal taxon, the Discocephalida. Both morphological and morphogenetic features indicate that the pseudoamphisiellids should be placed in the order Discocephalida but as a sister group to other typical discocephalids. Thus we propose establishing a new suborder, Pseudoamphisiellina subord. n. The new taxon is diagnosed by the following characteristics: (i) two distantly separated midventral rows that are morphogenetically formed with an urostylid mode; (ii) absence of the "frontoterminal row", which is formed from the posterior-most frontoventral-transverse cirral anlage in all other typical urostylids; (iii) numerous caudal cirri that derive from each of the dorsal kinety anlagen; (iv) right marginal row that has a unique de novo origin; and (v) inhabiting periphytic communities. The validity of the suborder Pseudoamphisiellina is firmly supported by molecular data.

A new urostylid ciliate, Anteholosticha petzi n. sp., isolated from the northern China seas, was studied using live observation and protargol impregnation. It differs from all the congeners mainly in the highly flexible and variable body shape, its red-brown to brick-red colour, and the possession of three types of cortical granules. Analysis of morphometric and molecular data confirm the validity of A. petzi as a distinct species. Anteholosticha petzi n. sp. is characterized as follows: by having 3 frontal, 1 buccal, 2 frontoterminal, 2 pretransverse, and 8-11 transverse cirri; a midventral row that comprises 10-16 cirral pairs and extends ca. 60% of cell length; and 3 bipolar dorsal kineties. Ontogenesis is similar to that in Anteholosticha warreni except for the formation of the oral primordium and is characterized by: (1) the parental adoral membranelles are completely renewed and the oral primordium is formed de novo; and (2) the anlagen for the frontal-ventral-transverse cirri are formed as primary primordia. The small subunit rRNA gene sequence of A. petzi n. sp. was also compared with that of its congeners with the sequence differences ranging from 0.39% to 8.62%. Phylogenetic trees based on the SSU rRNA gene sequence were constructed, indicating the nonmonophyly of the genus Anteholosticha, as supported by the approximately unbiased test., (© 2011 The Author(s). Journal of Eukaryotic Microbiology© 2011 International Society of Protistologists.)

The cortical development of Diophryopsis hystrix, a small marine euplotid ciliate, was observed during binary division. The pattern of morphogenesis is generally similar to that of other Diophrys-like species, with the exception of the marginal cirrus, which develops in a unique manner in D. hystrix being formed from the posterior end of the dorsal kinety anlage, in a similar manner to the formation of the caudal cirri. In the small subunit (SS) rRNA gene sequence tree, Diophryopsis represents a distinct clade separate from Diophrys. Furthermore, our ontogenetic and SSrRNA gene sequence data both support the suggestion that the Diophrys complex is sister to Uronychia, and should be considered as a distinct subfamily within the family Uronychiidae, i.e. Diophryinae Jankowski, 1979, comprising Diophrys, Diophryopsis, and Paradiophrys. Diagnoses of the subfamilies Diophryinae and Uronychiinae are provided.

A population of Kiitricha minuta Xu et al., 2008, a small kiitrichid ciliate, was isolated from a brackish water sample in Jiaozhou Bay, Qingdao, northern China. After comparison of its morphology and infraciliature, it is believed that this morphotype should be assigned to the genus Caryotricha; hence, a new combination is suggested, Caryotricha minuta (Xu et al., 2008) nov. comb. The small-subunit (SSU) rRNA gene sequence was determined in order to elucidate the phylogenetic position of this poorly known, ambiguous genus. The organism can be clearly separated from its congener, Caryotricha convexa Kahl, 1932, by the extremely shortened ventral cirral rows in the posterior ends. Based on the data available, an improved diagnosis is given for the genus: marine Kiitrichidae with prominent buccal field; two highly developed undulating membranes; non-grouped, uniform cirral rows on both ventral and dorsal sides; enlarged transverse cirri present, which are the only differentiated cirri; marginal cirri not present; one short migratory row located posterior to buccal field; structure of dorsal kineties generally in Kiitricha pattern. The sequence of the SSU rRNA gene of C. minuta differs by 13 % from that of Kiitricha marina. Molecular phylogenetic analyses (Bayesian inference, least squares, neighbour joining, maximum parsimony) indicate that Caryotricha, together with Kiitricha, diverges at a deep level from all other spirotrichs. Its branching position is between Phacodiniidia and Licnophoridia. The results strongly support the distinct separation of the Kiitricha-Caryotricha clade, which always branches basal to the Stichotrichia-Hypotrichia-Oligotrichia-Choreotrichia assemblage. These results also confirm the previous hypothesis that the Kiitricha-Caryotricha group, long assumed to be a close relation to the euplotids, represents a taxon at subclass level within the spirotrichs.

The small subunit rRNA (SSrRNA) genes of seven species of urostyloids representing four genera were sequenced. These were: Apokeronopsis crassa, A. bergeri, Anteholosticha sp-QD-1, Metaurostylopsis sp-QD-1, M. sp-QD-2, M. sp-QD-3 and Thigmokeronopsis sp-QD-1. Gene trees were constructed in order to investigate their phylogenetic relationships. The results indicate that: (1) Apokeronopsis, Thigmokeronopsis and Metaurostylopsis form a well-supported, clearly isolated, monophyletic group; (2) Metaurostylopsis species analysed consistently group together indicating that it is a well-outlined genus; (3) the validity of the genus Apokeronopsis is supported; (4) the separation of Holosticha and Anteholosticha is supported although Anteholosticha species exhibit a high molecular diversity; (5) Pseudokeronopsis and Thigmokeronopsis, which have been considered closely related, may not share a recent common ancestor, casting doubt on the monophyly of the family Pseudokeronopsidae.

The cortical development during binary fission of the relatively poorly known stichotrich ciliate, Trachelostyla pediculiformis (Cohn, 1866) Borror, 1972, found in coastal waters near Qingdao, China, was investigated using the protargol impregnation method. The morphogenetic process reveals some pretty unusual characteristics, which do not follow the Oxytricha-pattern: (1) the parental oral apparatus is entirely renewed from an oral primordium formed de novo in the proter; (2) in the proter, the parental undulating membranes are not involved in the formation of the newly formed oral primordium; both undulating membrane-anlagen (UM-anlage) and frontoventral-transverse cirral anlagen (FVT-anlagen) develop from the oral primordium in the proter; (3) the dorsal kineties (DK) are generated in a unique way, that is, in both dividers, two separate groups of DK-anlagen develop in the right- and left-most DK, generate all the DK and evolve to replace the old structures; (4) three caudal cirri are formed at the posterior ends of three right-most dorsal kinety anlagen; (5) eight frontal, five ventral and five transverse cirri are derived from six streaks, namely, the UM-anlage and 5 FVT-anlagen; the cirri are segregated from these anlagen in the pattern 1:3:3:3:4:4 (from left to right) in the Oxytricha mode. Based on both SSrRNA gene sequencing and morphogenetic data, the systematic positions of the genus Trachelostyla Borror, 1972 as well as the family Trachelostylidae Small and Lynn, 1985 are briefly analyzed. The results indicate that this genus/family could be a highly isolated lineage and might be ancestral to other well-known oxytrichids.

The morphologically unique genus Gastrocirrhus has been considered a distinct but systematically uncertain euplotid due to the absence of both morphogenetic and molecular information. Based on the small subunit rRNA gene sequence, the phylogenetic position of Gastrocirrhus monilifer Ozaki & Yagui, 1942 was re-addressed using multiple algorithms (neighbor-joining, maximum parsimony, least-squares, and Bayesian inference methods). Results indicate that: (1) all phylogenetic trees using different methods are nearly identical in topology, placing G. monilifer closest to Euplotidium arenarium; (2) Gastrocirrhus and Euplotidium form a monophyletic group, namely the family Gastrocirrhidae, and appear to be intermediate taxa bridging the evolution of the Diophrys-Uronychia and Euplotes-complexes (i.e. Euplotes, Certesia, and Aspidisca); (3) the order Euplotida is a paraphyletic group composed of three deeply diverged clades (Euplotes-Certesia-Aspidisca-Gastrocirrhus-Euplotidium; Uronychia-Diophrys; and Prodiscocephalus); (4) together with Prodiscocephalus, the Diophrys-Uronychia complex forms a group at the suborder level and is placed at the root of the order Euplotida, and (5) results from molecular analyses conspicuously challenge the conclusions deduced from morphological as well as morphogenetical investigations-the characteristics traditionally used to define the euplotid taxa at the generic level and/or above may not be uniformly reliable.

The "well-known" marine hypotrichous ciliate, Amphisiella marioni Gourret & Roeser, 1888 has been repeatedly misidentified for over a century, which has led to great confusion in the species identification. Based on a population collected from mariculture water in Qingdao (Tsingtao), north China, the morphology and infraciliature were investigated using live observations and the protargol impregnation method. The Chinese population corresponds perfectly with the original description by Gourret and Roeser (1888). As the type species of Amphisiella, its morphological characteristics include: an elongated body about 90-150 microm long in vivo; with grouped cortical granules arranged in irregular rows throughout the whole body; a contractile vacuole located slightly behind mid-body; adoral zone of membranelles slightly bipartite in structure with the anterior part ventrally located; amphisiellid median cirral row (ACR) extending to the level of the transverse cirri (TC); about eight frontal cirri left of the ACR; closely spaced marginal rows, displaced inwards, each with about 32 cirri; six TC arranged in a V-shape; no caudal cirrus; five to six dorsal kineties; and typically two macronuclei. We conclude that the populations described by Mansfeld (1923) and Wicklow (1982), respectively, were misidentified. To clarify the taxonomic status of this species, the population from the northern Chinese coast of the Yellow Sea is designated as a neotype.

The morphology and infraciliature of the type species of the ciliate genus Trachelostyla, T. pediculiformis (Cohn, 1866) Borror, 1972, collected from the Bohai Sea near Tianjin, north China, were investigated using live observation and protargol impregnation. The Chinese population corresponds well with the original description, as follows: size about 80-150 x 20-30 microm in vivo; body dorsoventrally flattened and non-spiral; outline elongate, with anterior region conspicuously narrowed while posterior not; on average 14 macronuclear nodules, two micronuclei and 42 adoral membranelles; 16-24 cirri in left and 21-31 in right marginal row. In total 18 frontoventral-transverse cirri: constantly 11 cirri in frontal area and two ventral ones together with five enlarged transverse cirri (TC). Three inconspicuous caudal cirri (CC); six dorsal kineties with prominent cilia. The literature on T. pediculiformis is critically reviewed, showing that the descriptions so far do not agree very well. To clarify the taxonomic status of this species, the population from the Chinese coast of the Bohai Sea is designated as a neotype. The small subunit rRNA gene was sequenced for the neotype and the molecular phylogenetic tree basically supports the establishment of the family Trachelostylidae Small & Lynn, 1985. Based on the data obtained, the genus Trachelostyla Borror, 1972 is redefined thus: dorsoventrally flattened trachelostylids, body non-spirally twisted and elongate, with peristomal region conspicuously narrowed; ciliature generally in 11:2:5:3 pattern, i.e. 11 cirri in frontal region, two ventral cirri located anterior to five TC, three CC present; one left and one right row of marginal cirri not confluent posteriorly. A new genus Spirotrachelostyla nov. gen. is proposed to include the taxa which were previously assigned to Trachelostyla but characterized by spirally twisted, spindle-like body shape and a variable number of cirri in the peristomal area. Three new combinations are suggested: Spirotrachelostyla spiralis (Dragesco & Dragesco-Kernéis, 1986) nov. comb. [basionym: Trachelostyla spiralis Dragesco & Dragesco-Kernéis, 1986], S. tani (Hu & Song, 2002) nov. comb. [basionym: T. tani Hu & Song, 2002] and S. simplex (Kahl, 1932) nov. comb. [basionym: Stichotricha simplex Kahl, 1932].

In order to address the confused taxonomy of morphotypes within the genus Pseudokeronopsis, the small subunit ribosomal RNA (SS rRNA) gene and the internal transcribed spacer (ITS1)-5.8S-ITS2 region for 13 populations/clones of morphologically similar Pseudokeronopsis species, Pseudokeronopsis flava, Pseudokeronopsis rubra and Pseudokeronopsis carnea, were sequenced and compared at inter- and intra-specific levels. Different geographical/time interval isolates belonging to the same species were slightly divergent, while clones from the same strain had identical SS rRNA gene sequences. Compared with the SS rRNA gene sequence, the sequence of the ITS1-5.8S-ITS2 region of Pseudokeronopsis revealed higher diversity, with nucleotide dissimilarities of 3.9–4.9% at the intra-specific level and 8.0–10.5% at the inter-specific level. There were several minor differences among ITS2 secondary structures of three Pseudokeronopsis species, while three Pseudok. carnea populations were identical. Phylogenetic analyses using multiple algorithms and different species selections confirm that Pseudok. flava, Pseudok. rubra and Pseudok. carnea form a monophyletic group within the urostylids. The result also supports the closest relationship of Pseudokeronopsis and Pseudourostyla that forms the so-called Acaudalia Berger (2006) . [ABSTRACT FROM AUTHOR]