Trichodinid ectoparasites (Ciliophora, Peritrichia) from the tiger puffer Takifugu rubripes in the Yellow Sea, with revision of Trichodina jadranica Raabe,1958

Two ectoparasitic ciliates, Trichodina fugu Imai et al., 1997 and T. jadranica Raabe, 1958, found on the gills and skin of the maricultured tiger puffer Takifugu rubripes on the China coast of the Yellow Sea, were studied using the dry silver nitrate method. Trichodina fugu is distinguished by its almost rod-shaped denticle blades. Trichodina jadranica is usually described as a small trichodinid with a clear central circle in the adhesive disc and with a low number of denticles. However, the data available suggest that the species is highly variable in morphometry and the Chinese population represents the largest in body size and denticle dimensions found to date. Based on the revision of T. jadranica, two major morphotypes, each represented by several populations are classified, differing in the shape of the blades, viz., distinctly curved and sickle-shaped with pointed distal ends (as in the classical T. jadranica) vs. less curved and more or less rectangle-like with rounded distal ends (as in T. domerguei gobii). Trichodina domerguei gobii Raabe,.1959, which was synonymised with T. jadranica, is thus elevated to species rank. Furthermore, Trichodina jadranica noblei Lom, 1970 has straight and stout blades with broadly rounded distal ends and is raised to species rank: T noblei Lom, 1970. Trichodina jadranica sensu Xu et al., 1995 shows high similarities in denticle shape and dimensions as well as the central granule pattern with T chlamydis Xu et al., 1999. Thus, it is synonymised with the latter species.

On two species of spider crabs of the genus Doclea (Crustacea : Decapoda : Brachyura : Majidae : Pisinae) from China, one of which is new

A new species of spider crab, Doclea unidentata, is described from the South China Sea. Allied to D. brachyrhynchos Bleeker, 1856, and D. macracanthus Bleeker, 1856, it can easily be distinguished by its very short, unidentate rostrum. The identity of Doclea canalifera Stimpson, 1857, is resolved with the selection of a neotype, and it is here regarded as a senior subjective synonym of D. japonica Ortmann, 1893. The taxonomy of this species as well as the allied D. ovis (Fabricius, 1787) is also discussed.

Classification of jinjiang oysters Crassostrea rivularis (Gould, 1861) from China, based on morphology and phylogenetic analysis

The jinjiang oyster Crassostrea rivularis [Gould, 1861. Descriptions of Shells collected in the North Pacific Exploring Expedition under Captains Ringgold and Rodgers. Proc. Boston Soc. Nat. Hist. 8 (April) 33-40] is one of the most important and best-known oysters in China. Based on the color of its flesh, two forms of C rivularis are recognized and referred to as the "white meat" and 11 red meat" oysters. The classification of white and red forms of this species has been a subject of confusion and debate in China. To clarify the taxonomic status of the two forms of C. rivularis, we collected and analyzed oysters from five locations along China's coast using both morphological characters and DNA sequences from mitochondrial 16S rRNA and cytochrome oxidase 1, and the nuclear 28S rRNA genes. Oysters were classified as white or red forms according to their morphological characteristics and then subjected to DNA sequencing. Both morphological and DNA sequence data suggest that the red and white oysters are two separate species. Phylogenetic analysis of DNA sequences obtained in this study and existing sequences of reference species show that the red oyster is the same species as C. ariakensis Wakiya [1929. Japanese food oysters. Jpn. J. Zool. 2, 359-367.], albeit the red oysters from north and south China are genetically distinctive. The white oyster is the same species as a newly described species from Hong Kong, C. hongkongensis Lam and Morton [2003. Mitochondrial DNA and identification of a new species of Crassostrea (Bivalvia: Ostreidae) cultured for centuries in the Pearl River Delta, Hong Kong, China. Aqua. 228, 1-13]. Although the name C. rivularis has seniority over C. ariakensis and C. hongkongensis, the original description of Ostrea rivularis by Gould [1861] does not fit shell characteristics of either the red or the white oysters. We propose that the name of C. rivularis Gould [1861] should be suspended, the red oyster should take the name C. ariakensis, and the white oyster should take the name C. hongkongensis. (C) 2004 Elsevier B.V. All rights reserved.

Classification of common oysters from North China

Oysters are commonly found on rocky shores along China's northern coast, although there is considerable confusion as to what species they are. To determine the taxonomic status of these oysters, we collected specimens from nine locations north of the Yangtze River and conducted genetic identification using DNA sequences. Fragments from three genes, mitochondrial 165 rRNA, mitochondria! cytochrome oxidase I (COI), and nuclear 285 rRNA, were sequenced in six oysters from each of the nine sites. Phylogenetic analysis of all three gene fragments clearly demonstrated that the small oysters commonly found on intertidal rocks in north China are Crassostrea gigas (Thunberg, 1793), not C. plicatula (the zhe oyster) as widely assumed. Their small size and irregular shell characteristics are reflections of the stressful intertidal environment they live in and not reliable characters for classification. Our study confirms that the oysters from Weifang, referred to as Jinjiang oysters or C. rivularis (Gould, 1861), are C. ariakensis (Wakiya, 1929). We found no evidence for the existence of C. talienwhanensis (Crosse, 1862) and other Crassostrea species in north China. Our study highlights the need for reclassifying oysters of China with molecular data.

Molecular evidence for double maternal origins of the diploid hybrid Hippophae goniocarpa (Elaeagnaceae)

Homoploid hybrid plant species are rare, and the mechanisms of their speciation are largely unknown, especially for homoploid hybrid tree species. Two contrasting hypotheses have been proposed to explain the origin of Hippophae goniocarpa: (1) it is a diploid hybrid originating from H. rhamnoides ssp. sinensis x H. neurocarpa ssp. neurocarpa, and (2) it originated via marginal differentiation from H. rhamnoides ssp. sinensis. Regardless of which of these hypotheses is true (if either), previous studies have suggested that H. rhamnoides ssp. sinensis is the only maternal donor for this hybrid species. In this study, we aim to elucidate the maternal composition of H. goniocarpa and to test the two hypotheses. For this purpose, we sequenced the maternal chloroplast DNA trnL-F region of 75 individuals representing H. goniocarpa, H. rhamnoides ssp. sinensis, and H. neurocarpa ssp. neurocarpa in two co-occurring sites of the taxa. Seven haplotypes were identified from three taxonomic units, and their phylogenetic relationships were further constructed by means of maximum parsimony, maximum likelihood, and network analyses. These seven haplotypes clustered into two distinct, highly divergent lineages. Two haplotypes from one lineage were found in H. rhamnoides ssp. sinensis, and five (representing the other lineage) in H. neurocarpa ssp. neurocarpa. Hippophae goniocarpa shared four common haplotypes from both lineages, but the haplotypes detected from the two populations differed to some extent, and in each case were identical to local haplotypes of the putative parental species. Thus, both H. rhamnoides ssp. sinensis and H. neurocarpa ssp. neurocarpa appear to have together contributed to the maternal establishment of H. goniocarpa. These results clearly demonstrate that the marginal origin hypothesis should be rejected, and support the hybrid origin hypothesis. Hippophae goniocarpa exhibits a sympatric distribution with its two parent species, without occupying new niches or displaying complete ecological isolation. However, this species has effectively developed reproductive isolation from its sympatric parent species. Our preliminary results suggest that H. goniocarpa may provide a useful model system for studying diploid hybrid speciation in trees. (c) 2008 The Linnean Society of London.

Phylogenetic origins of the Himalayan endemic Dolomiaea, Diplazoptilon and Xanthopappus (Asteraceae : Cardueae) based on three DNA regions

Background and Aims It is an enduring question as to the mechanisms leading to the high diversity and the processes producing endemics with unusual morphologies in the Himalayan alpine region. In the present study, the phylogenetic relationships and origins of three such endemic genera were analysed, Dolomiaea, Diplazoptilon and Xanthopappus, all in the tribe Cardueae of Asteraceae.Methods The nuclear rDNA internal transcribed spacer (ITS) and plastid trnL-F and psbA-trnH regions of these three genera were sequenced. The same regions for other related genera in Cardueae were also sequenced or downloaded from GenBank. Phylogenetic trees were constructed from individual and combined data sets of the three types of sequences using maximum parsimony, maximum likelihood and Bayesian analyses.Key Results The phylogenetic tree obtained allowed earlier hypotheses concerning the relationships of these three endemic genera based on gross morphology to be rejected. Frolovia and Saussurea costus were deeply nested within Dolomiaea, and the strong statistical support for the Dolomiaea-Frolovia clade suggested that circumscription of Dolomiaea should be more broadly redefined. Diplazoptilon was resolved as sister to Himalaiella, and these two together are sister to Lipschitziella. The clade comprising these three genera is sister to Jurinea, and together these four genera are sister to the Dolomiaea-Frolovia clade. Xanthopappus, previously hypothesized to be closely related to Carduus, was found to be nested within a well-supported but not fully resolved Onopordum group with Alfredia, Ancathia, Lamyropappus, Olgaea, Synurus and Syreitschikovia, rather than the Cardinis group. The crude dating based on ITS sequence divergence revealed that the divergence time of Dolomiaea-Frolovia from its sister group probably occurred 13.6-12.2 million years ago (Ma), and the divergence times of the other two genera, Xanthopappus and Diplazoptilon, from their close relatives around 5.7-4.7 Ma and 2.0-1.6 Ma, respectively.Conclusions The findings provide an improved understanding of the intergeneric relationships in Cardueae. The crude calibration of lineages indicates that the uplifts of the Qiinghai -Tibetan Plateau since the Miocene might have served as a continuous stimulus for the production of these morphologically aberrant endemic elements of the Himalayan flora.

Mitochondrial DNA phylogeny of two morphologically enigmatic fishes in the subfamily Schizothoracinae (Teleostei : Cyprinidae) in the Qinghai-Tibetan Plateau

The complete mitochondrial DNA (mtDNA) cytochrome b gene (1140 bp) was sequenced in Herzenstein macrocephalus and Gymnocypris namensis and in 13 other species and sub-species (n = 22), representing four closely related genera in the subfamily Schizothoracinae. Conflicting taxonomies of H. macrocephalus and G. namensis have been proposed because of the character instability among individuals. Parsimony, maximum likelihood and Bayesian methods produced phylogenetic trees with the same topology and resolved several distinctive clades. Previous taxonomic treatments, which variously placed these two species of separate genera or as sub-species, are inconsistent with the mtDNA phylogeny. Both H. macrocephalus and G. namensis appear in a well-supported clade, which also includes nine species of Schizopygopsis, and hence should be transferred to the genus Schizopygopsis. Morphological changes are further illustrated, and their adaptive evolution in response to the local habitat shifts during the speciation process appears to be responsible for conflicting views on the systematics of these two species and hence the contrasting taxonomic treatments. These species are endemic to the Qinghai-Tibetan Plateau, a region with a history of geological activity and a rich diversity of habitats that may have result in the parallel and reversal evolution of some morphological characters used in their taxonomies. Our results further suggest that speciation and morphological evolution of fishes in this region may be more complex than those previously expected. (c) 2007 The Authors Journal compilation (c) 2007 The Fisheries Society of the British Isles.

Phylogenetic relationships of five pika species (genus Ochotona) based on mitochondrial DNA restriction maps

Restriction site mapping of mitochondrial DNA (mtDNA) with 16 restriction endonucleases was used to examine the phylogenetic relationships of Ochotona cansus, O. huangensis, O. thibetana, O. curzoniae and O. erythrotis. A 1-kb length variation between O. erythrotis of subgenus Pika and other four species of subgenus Ochotona was observed, which may be a useful genetic marker for identifying the two subgenera. The phylogenetic tree constructed using PAUP based on 61 phylogenetically informative sites suggests that O. erythrotis diverged first, followed by O. cansus, while O. curzoniae and O. huangensis are sister taxa related to O. thibetana, The results indicate that both O. cansus and O. huangensis should be treated as independent species. If the base substitution rate of pikas mtDNA was 2% per million years, then the divergence time of the two subgenera, Pika and Ochotana, is about 8.8 Ma ago of late Miocence, middle Bao-dian of Chinese mammalian age, and the divergence of the four species in subgenus Ochotona would have occurred about 2.5 - 4.2 Ma ago, Yushean of Chinese mammalian age. This calculation appears to be substantiated by the fossil record.