Spinibarbus

Abstract: Spinibarbus fishes occur in the rivers from the south of Qinling Mountains to the north of Yuanjiang River,including Taiwan and Hainan islands.About the generic status and the identification of species,different opinions have been proposed.So far,15 specific nomenclatures have been reported,being placed in really different genera such as Puntius,Barbodes,Spinibarbichthys,Spinibarbus,Mystacoleucus and Mytsya.Most of these nomenclatures have been recognized to be synonyms.In order to determine the taxonomic status and to clarify the nomenclative confusions for the spinibarbid fishes,we carefully examined 104 spinibarbid specimens and some skeletal specimens deposited in Kunming Institute of Zoology.Comparisons indicate that spinibarbid fishes are distinguished from all other genera of the subfamily Barbinae by following characters:the last supraneural disappeared from above the last predorsal vertebra;the 4th neural spine well developed,being almost as tall as neural complex;a well developed precumbent spine presents in front of dorsal fin origin.These characters further confirm the proposal that spinibarbid fishes represent a special lineage within subfamily Barbinae and should be given a generic status.Through the revision,5 specific nomenclatures are recognized to be valid to the genus Spinibarbus,and S.elongatus is treated for the first time as a synonym of S.hollandi.

Abstract: The taxonomic problem of the cyprinid species of genus Spinibarbus, occurring in southern China and northern Vietnam, was resolved on the basis of molecular and morphological analyses. Spinibarbus caldwelli and Spinibarbus hollandi have a smooth posterior edge of the last unbranched dorsal fin ray among species in the genus. Spinibarbus caldwelli is currently regarded as a junior synonym of S. hollandi because of ambiguities in diagnostic characters. In this article, 11 mtDNA cytochrome b sequences of Spinibarbus specimens were analyzed together with Barbodes gonionotus and Puntius conchonius as outgroups. Our results showed that specimens identified as S. hollandi from Taiwan were different from those from the Asian mainland at a high level of genetic divergence (0.097-0.112), which is higher than that between the two valid species, S. sinensis and S. yunnanensis ( 0.089), and suggested that Taiwan specimens should be considered as a different species from the Asian mainland one. In a molecular phylogenetic analysis, the sister-group relationship between Taiwan specimens and the Asian mainland specimens was supported strongly by a high confidence level ( 100% in bootstrap value). Further analysis of morphological characters showed that overlap of diagnostic characters is much weaker than previously suggested. Taiwan specimens had 8 branched rays in the dorsal fin, whereas those from the mainland had almost 9-10. The molecular and morphological differences suggest S. caldwelli to be valid. The molecular divergence shows the genetic speciation of S. hollandi and S. caldwelli might have occurred 5.6-4.9 million years ago; the former could be a relict species in Taiwan, and the latter dispersed in the Asian mainland.

Abstract: The cyprinid genus Spinibarbus consists of 5 species. They form into a monophyly by three synapomorphies.Based on 19 external and skeletal characters, the most parsimonious cladogram is constructed for Spinbarbus fishes. Sister groups A (S. hollandi) and B-E (S.sinensis+S.denticulatus+S.yunnanensis+S.polylepis) represent the first phyletic branching within the genus Spinbarbus. The phyletic division of second sister groups B(S.sinensis)and C-E(S.denticulatus+S.yunnanensis+S.polylepis) is pupposed to be resulted from the upheaval of Ynnan-Guizhou Plateau and the subsequent drainages' division. The phyletic division of third sister groups C(S.denticulatus) and D-E(S.yunanensis + S.polylepis) is supposed to be resulted from the environmental differentiation between Yunnan-Guizhou Plateau and the lowlands of middle and lower Pearl and Yuanjiang Rivers.

Abstract: Spinibarbus caldwelli(Cyprinidae,Barbine,Spinibarbus)is a kind of small to middle sized fish dwelling in the middle or at the bottom of rivers,widely distributed in Yuanjiang River, Zhujiang River, Jiulongjiang River, Minjiang River, Changjiang River, Hainan and Taiwan. Because of the differences of ecological environments, morphological variations were found among the samples of S. caldwelli from different localities. In the present paper, with Spinibarbus sinensis as the outgroup, the cytochrome b genes(1140)of S. caldwelli specimens from different localities were sequenced to study biogeographical process of this species. Molecular phylogenetic trees were constructed according to the neighbor-joining method and the most parsimony method in Mega 2.0 software. The results showed that variations between samples from Changjiang and Zhujiang rivers, Changjiang and Minjiang rivers, Changjiang and Jiulongjiang rivers,were 1.2%-2.3%,2.7%-3.7%,and 3.1%-4.2% respectively. All these are much lower than the interspecies variations (13.2%-14.6%). These variations and molecular phylogenetic trees indicate that the biogeographical process might be that water systems in southeastern coast region separated from the inland water systems first, then separation between Zhujiang River and Changjiang River occurred,and these events should be in the Quaternary.