Zoological Studies

Vol. 48 No. 4, 2009

Speciation and Phylogeography of Opsariichthys bidens (Pisces: Cypriniformes: Cyprinidae) in China: Analysis of the Cytochrome b Gene of mtDNA from Diverse Populations

Gao-Yan Li1,2, Xu-Zhen Wang3, Ya-Hui Zhao1, Jie Zhang1, Chun-Guang Zhang1,*, and Shun-Ping He3

1Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
3Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China

Gao-Yan Li, Xu-Zhen Wang, Ya-Hui Zhao, Jie Zhang, Chun-Guang Zhang, and Shun-Ping He (2009) The cyprinid fish Opsariichthys bidens GŁnther is distributed in all major river systems of continental East Asia, and represents an attractive model for phylogeographic studies among cyprinid species or within a given species.  In this study, we investigated the phylogeographic and demographic history of this species, using partial sequences of the cytochrome (cyt) b gene in mitochondrial (mt)DNA.  Fish samples were collected from almost all major river systems where O. bidens is distributed in China.  Sequence analysis showed remarkably high polymorphism, with 125 haplotypes in the 234 specimens examined, and with 89.8% of haplotypes occurring in only 1 specimen.  A neutrality test indicated that some groups were not at mutation-drift equilibrium, suggesting a past population expansion.  These results were supported by a mismatch distribution analysis.  Based on our analysis, O. bidens consists of 4 groups belonging to 2 clades.  The divergence time of the 2 clades was estimated to be 11.06-8.04 my.  This value corresponds to the time of the 2nd uplift of the Qinghai-Tibet Plateau, the emergence of the East Asian monsoon, and the Epoch-6 Event.  A two species scheme is proposed.

Key words: Demographic history, Genetic divergence, Mismatch distribution analysis, Molecular clock, Neutrality test.

*Correspondence:  Shung-Ping He and Chun-Guang Zhang contribute equally to this work. Tel: 86-10-64807116; 86-27-68780430.  Fax: 86-10-64807116; 86-27-68780430.  E-mail:fish@ioz.ac.cn; clad@ihb.ac.cn