Three new species of Tubificinae, Oligochaeta, from two plateau lakes in Southwest China

Three new species of Tubificinae (Naididae, Oligochaeta), Varichaetadrilus vestibulatus n. sp., Aulodrilus apeniatus n. sp., and Ilyodrilus mesoprostatus n. sp., are reported from Fuxian Lake and Xingyun Lake of Yunnan Province, Southwest China. V. vestibulatus differs from its allies by possessing modified spermathecal chaetae and thinner cylindrical penial sheaths. A. apeniatus is unique in the genus by having no penis. I. mesoprostatus is distinguishable from congeners by its prostate glands joining middle portion of atria and having concave, cone-shaped cuticular penial sheaths. Twenty-eight species of freshwater oligochaetes have hitherto been recorded from Yunnan Province, including five endemic species from three plateau lakes.

Pseudobagrus fui Miao, a valid bagrid species from the Yangtze River drainage, South China (Teleostei: Bagridae)

Pseudobagrus fui Miao is a valid bagrid species that can be separated from all its congeners in having 27-33 anal-fin rays. Among the species of Pseudobagrus, it forms part of a group of approximately 20 species putatively characterized by having a smooth anterior margin of the pectoral-fin spine and short maxillary barbels not extending to the base of the pectoral-fin spine. Pseudobagrus fui, together with P. nitidus and P. vachelli, can be differentiated from all other fork-tailed species of this group by having no fewer than 20 branched anal-fin rays, the posterior end of the anal-fin base posterior to the vertical through the posterior end of the adipose-fin base, and anal-fin base longer than the adipose-fin base. It further differs from P. nitidus in having a gas bladder without beaded lateral and posterior margins, and from P. vachelli in having short maxillary barbels not extending to the base of the pectoral-fin spine. Pseudobagrus fui is currently known from the main stream of the upper Yangtze River and its tributaries, the Min River, Jialing River, Tuo River, Wu River and Chishui River in Sichuan Province, Guizhou Province, and the Chongqing City. The identity and nomenclature of Pseudobagrus nitidus is also discussed.

Saprolegnia brachydanis, A New Oomycete Isolated from Zebra Fish

Saprolegnia brachydanis is described from zebra fish (Brachydanio rerio) in Wuhan, Hubei Province, China. The species is illustrated and compared with other species of the genus. The distinctive characteristics of S. brachydanis are the production of glomerulate oogonia wrapped around by predominantly monoclinous antheridia which can be up to eight in one oogonium. The oogonial stalks are short, straight, or curved and the antheridia, twisted, can enwind one or more oogonia. The oospores cannot mature or easily abort. Morphological features of the oomycete and the ITS sequence of its rDNA as well as the comparison with related species are discussed in this article.

Study on freshwater genus Peridinium (Dinophyta) from China

Peridinium is an important genus of freshwater armoured dinoflagellates with two more intercalary plates (sensu Bourrelly). A few species of Peridinium were known from China heretofore. The plate pattern is one of the important criteria for the taxonomy of Peridinium, and it was difficult to visualize their plate patterns under normal light microscope. For editing of Flora Algarum Sinicarum Aquae Dulcis, 11 species of Peridinium collected from various freshwater habitats of China are described. Among them, 6 species are first reported from China. They are P. gatunense Nygaard, P. gutwinskii Woloszynska, P. lomnickii Woloszynska, P. palatinum Lauterborn, P. striolatum Playfair, and P. zonatum Playfair. Epifluorescence microscopy and scanning electron microscopy, and also light microscopy were employed for their structure and patterns of thecal plates.

Study of Apiosoma piscicola (Blanchard 1885) occurring on fry of freshwater fishes in Hongze, China with consideration of the genus Apiosoma

Apiosoma piscicola (Blanchard 1885) was reported from fry of Carassius auratus (Var. pengze) and Ctenopharyngodon idella during parasite surveys in May 2005 and June 2006 at Hongze Lake Fish Hatchery, Jiangsu province, China. Twelve morphometric parameters were used to describe this peritrich in detail in the present study and comparisons were made with other reports. Its synonyms, Glossatella cylindriformis (Chen 1955) and Apiosoma magna (Banina 1968), were clarified based on reliable data. A. piscicola was still considered somewhat host-specific by us, especially to cyprinids, although it shows a quite wide limit of host variability. The telotroch was also observed, and its structures were described herein. Besides, the difficulties of the generic taxonomy were discussed and some suggestions were given.

Investigations into the perplexing interrelationship of the Genus Takifugu Abe, 1949 (Tetraodontiformes, Tetraodontidae)

The phylogenetic relationships within the genus Takifugu Abe, 1949 (Tetraodontiformes, Tetraodontidae) remain unresolved. Because of the use of Takifugu as model organisms, the resolution of these relationships is crucial for the interpretation of evolutionary trends in biology. Pufferfishes of this genus are comprised of a comparatively small number of species and are mainly distributed along the coastal region of the western part of the Sea of Japan and the coastline of China. Mitochondrial gene sequences were employed to test the phylogenetic hypotheses within the genus. Seventeen species of the genus were examined. Molecular phylogenetic trees were constructed using the maximum parsimony, neighbor-joining, maximum likelihood and Bayesian methods. Our hypothesis of internal relationships within the genus differs from previous hypotheses. Our results indicate that (1) the genus Takifugu is a monophyletic assemblage; (2) the genus is divided into 6 subgroups based on the molecular data; and (3) there is low genetic diversity among the species within this genus. In addition, speciation within Takifugu appears to be driven by hybridization and isolation by distribution. Our results also suggested that the taxonomy in the genus should be clarified based on both molecular and morphological data.

Taxonomic notes on water bloom forming Microcystis species (Cyanophyta) from China - An example from samples of the Dianchi Lake

Ten common species of Microcystis, based on the examination of water samples from the Dianchi Lake, Yunnan, China, were morphologically described, and their taxonomy was also discussed. They are Microcystis aeruginosa, M botrys, M firma, M flos-aquae, M ichthyoblabe, M novacekii, M pseudofilamentosa, M smithii, M viridis and M wesenbergii. Taxonomic status of other Microcystis species reported in China was also evaluated.

The diverse Grania fauna (Clitellata : Enchytraeidae) of the Esperance area, Western Australia, with descriptions of two new species

Seven species of the marine enchytraeid genus Grania Southern, 1913 are described from sediments sampled during the 2003 International Workshop on the Marine Flora and Fauna of Esperance Bay and the Recherche Archipelago, on the southern coast of Western Australia. Two species are new to science, the euryhaline Tasmanian G. dolichura Rota and Erseus, 2000 represents a new record for the state, and the remaining four species were known from other parts of Western Australia. Grania quaerens sp. n. is recognized by having a high chaetal index (= 5 short chaetal foot), small coelomocytes, penial apparati with long whip-like terminal stylets, conspicuous spermathecae with ectally bulbous ducts, and ectally granulated ampullae housing sperm rings in their ental region. Grania sperantia sp. n. is readily distinguishable by the complete lack of lateral chaetae, a multiple-banded pattern of the clitellum, extremely long sperm funnels, and the intrasegmental location of the spermathecal pores. The latter new species and four others in the collection (G. bykane Coates, 1990, G. crassiducta Coates, 1990, G. dolichura, and G. ersei Coates, 1990) are remarkable in possessing the head organ, a sensory structure unique to Grania that was not noted previously in Western Australian species. When considering the whole genus, the geographic pattern of the head organ appears southern-centred: of the 17 species of Grania reported to possess it, as many as 13 inhabit the southern latitudes. The seventh species of the Esperance collection, G. vacivasa Coates and Stacey, 1993, is notable for the kind of items found in its gut and the unusual appearance of its pygidium.

Utility of ITS1-5.8S-ITS2 sequences for species discrimination and phylogenetic inference of two closely related bucephalid digeneans (Digenea : Bucephalidae): Dollfustrema vaneyi and Dollfustrema hefeiensis

The complete internal transcribed spacer 1 (ITS1), 5.8S ribosomal DNA, and ITS2 region of the ribosomal DNA from 60 specimens belonging to two closely related bucephalid digeneans (Dollfustrema vaneyi and Dollfustrema hefeiensis) from different localities, hosts, and microhabitat sites were cloned to examine the level of sequence variation and the taxonomic levels to show utility in species identification and phylogeny estimation. Our data show that these molecular markers can help to discriminate the two species, which are morphologically very close and difficult to separate by classical methods. We found 21 haplotypes defined by 44 polymorphic positions in 38 individuals of D. vaneyi, and 16 haplotypes defined by 43 polymorphic positions in 22 individuals of D. hefeiensis. There is no shared haplotypes between the two species. Haplotype rather than nucleotide diversity is similar between the two species. Phylogenetic analyses reveal two robustly supported clades, one corresponding to D. vaneyi and the other corresponding to D. hefeiensis. However, the population structures between the two species seem to be incongruent and show no geographic and host-specific structure among them, further indicating that the two species may have had a more complex evolutionary history than expected.

Cloning and characterization of cytochrome c oxidase subunit I (COXI) in Gobiocypris rarus

In study of gene expression profile in cloned embryos which derived from D. rerio embryonic nuclei and G. rarus enucleated eggs, cytochrome c oxidase subunit I (COXI) of G. rarus, exhibiting difference at expression level between cloned embryos and zebrafish embryo, was cloned. Its full cDNA length is 1654 bp and contains a 1551 bp open reading frame, encoding a 5.64 kDa protein of 516 amino acids. The alignment result shows that mitochondrion tRNA(ser) is co-transcripted with COXI, which just was the 3'-UTR of COXI. Molecular phylogenic analysis based on COXI indicates G. rarus should belong to Gobioninae, which was not in agreement with previous study according to morphological taxonomy. Comparison of DNA with cDNA shows that RNA editing phenomenon does not occur in the COXI of G. rarus.

Phylogenetic relationships of the Chinese sisorid catfishes: a nuclear intron versus mitochondrial gene approach

Several recent molecular phylogenetic studies of the sisorid catfishes (Sisoridae) have challenged some aspects of their traditional taxonomy and cladistic hypotheses of their phylogeny. However, disagreement with respect to relationships within this family in these studies highlights the need for additional data and analyses. Here we subjected 15 taxa representing 12 sisorids genera to comprehensive phylogenetic analyses using the second intron of low-copy nuclear S7 ribosomal protein (rpS7) gene and the mitochondrial 16S rRNA gene segments both individually and in combination. The competing sisorid topologies were then tested by using the approximately unbiased (AU) test and the Shimodaira-Hasegawa (SH) test. Our results support previously suggested polyphyly of Pareuchiloglanis. The genus Pseudecheneis is likely to be nested in the glyptosternoids and Glaridoglanis might be basal to the tribe Glyptosternini. However, justified by AU and SH test, the sister-group relationship between Pseudecheneis and the monophyletic glyptosternoids cannot be rejected based on the second intron of rpS7 gene and combined data analyses. It follows that both gene segments are not suitable for resolving the phylogenetic relationships within the sisorid catfishes. Overall, the second intron of rpS7 gene yielded poor phylogenetic performance when compared to 16S rRNA gene, the evolutionary hypothesis of which virtually agreed with the combined data analyses tree. This phenomenon can be explained by the insufficient length and fast saturation of substitutions in the second intron of rpS7 gene, due to substitution patterns such as frequent indels (insertion/deletion events) of bases in the sequences during the evolution.

MtDNA phylogeny provides evidence of generic polyphyleticism for East Asian bagrid catfishes

We explore the intrafamilial relationships of East Asian bagrid catfishes (Hemibagrus, Pseudobagrus, Pelteobagrus, and Leiocassis) based on 245 sequences of 1092 bp mitochondrial cytochrome b fragments. Four haplotypes were found to be shared by Pseudobagrus ussuriensis, Pelteobagrus vachelli and Pelteobagrus nitidus. Phylogenetic trees were performed using the neighbor joining, maximum parsimony, maximum likelihood, and Bayesian likelihood methods. The phylogenetic trees based on NJ, MP, ML and BL inferences strongly support polyphyleticism for the currently recognized genera Pseudobagrus, Pelteobagrus and Leiocassis. However, the species currently assigned to these three genera form a robustly monophyletic group with relatively low genetic divergence. The structure of maxillary barbels and serrations on the anterior edge of the pectoral spines seem to be indicatory of appropriate phylogenetic traits. We propose that only Hemibagrus and Pseudobagrus are the only valid genera of East Asian bagrids.

Revised diagnosis of the genus Bangana Hamilton, 1822 (Pisces : Cyprinidae), with taxonomic and nomenclatural notes on the Chinese species

Most morphological characters diagnostic of the 13 Chinese species of the cyprinid genus Sinilabeo Rendahl, 1932, are identical to those of the genus Bangana Hamilton, 1822. Consequently, these 13 species are transferred to Bangana. A revised diagnosis is provided for the now-expanded genus Bangana, and a dichotomous key and taxonomic and nomenclatural notes are included for the following valid Chinese species: B. decora, B. dero, B. devdevi, B. discognathoides, B. lemassoni, B. lippa, B. rendahli, B. tonkinensis, B. tungting, B. wui, B. xanthogenys, B. yunnanensis, and B. zhui. Literature reports, by Chinese authors, of Sinilabeo dero from the upper Irrawady River basin, in Yunnan, are based on misidentifcations of B. devdevi. Sinilabeo cirrhinoides Wu and Lin in Wu, Lin, Chen, Chen and He, 1977, and S. laticeps Wu and Lin in Wu, Lin, Chen, Chen and He, 1977, are junior subjective synonyms of B. devdevi and B. lippa, respectively. Sinilabeo yunnanensis Wu, Lin, Chen, Chen and He, 1977, is an available name, and a lectotype is designated for the species. Bangana zhui ( Zheng and Chen, 1983) is a valid species distinct from B. yunnanensis.

Biogeography and molecular phylogeny of the genus Schizothorax (Teleostei : Cyprinidae) in China inferred from cytochrome b sequences

Aim: To test a vicariant speciation hypothesis derived from geological evidence of large-scale changes in drainage patterns in the late Miocene that affected the drainages in the south-eastern Tibetan Plateau. Location: The Tibetan Plateau and adjacent areas. Methods: The cytochrome b DNA sequences of 30 species of the genus Schizothorax from nine different river systems were analysed. These DNA sequences were analysed using parsimony, maximum likelihood and Bayesian methods. The approximately unbiased and Shimodaira-Hasegawa tests were applied to evaluate the statistical significance of the shortest trees relative to alternative hypotheses. Dates of divergences between lineages were estimated using the nonparametric rate smoothing method, and confidence intervals of dates were obtained by parametric bootstrapping. Results: The phylogenetic relationships recovered from molecular data were inconsistent with traditional taxonomy, but apparently reflected geographical associations with rivers. Within the genus Schizothorax, we observed a divergence between the lineages from the Irrawaddy-Lhuit and Tsangpo-Parlung rivers, and tentatively dated this vicariant event back to the late Miocene (7.3-6.8 Ma). We also observed approximately simultaneous geographical splits within drainages of the south-eastern Tibetan Plateau, the Irrawaddy, the Yangtze and the Mekong-Salween rivers in the late Miocene (7.1-6.2 Ma). Main conclusions: Our molecular evidence tentatively highlights the importance of palaeoriver connections and the uplift of the Tibetan Plateau in understanding the evolution of the genus Schizothorax. Molecular estimates of divergence times allowed us to date these vicariant scenarios back to the late Miocene, which agrees with geological suggestions for the separation of these drainages caused by tectonic uplift in south-eastern Tibet. Our results indicated the substantial role of vicariant-based speciation in shaping the current distribution pattern of the genus Schizothorax.

Acrossocheilus malacopterus, a new non-barred species of cyprinid from South China

Acrossocheilus malacopterus n. sp. is described from the Yuan Jiang (Red River) and Zhu Jiang basins in I South China. It is separated from other congeners by a combination of the following characters: an inconspicuously stripped body, 16 circumpeduncular scales, 47-49 lateral line scales, depth of caudal peduncle 7.8-9.3% SL, snout length 37.9-41.7% SL, dorsal-fin length 18.7-21.0% SL and last simple dorsal-fin ray slender with 8-10 fine serrations along posterior margin.