Biodiv Sci ›› 2010, Vol. 18 ›› Issue (3): 262-274.  DOI: 10.3724/SP.J.1003.2010.262

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Validity of Pseudobagrus sinensis and mitochondrial DNA diversity of Pseudobagrus fulvidraco populations in China

Xiying Ku1,2, Chuanjiang Zhou1,3, Shunping He1,*()   

  1. 1 Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072
    2 Graduate University of the Chinese Academy of Sciences, Beijing 100049
    3 School of Life Science, Southwest University, Chongqing 400715
  • Received:2009-10-29 Accepted:2010-01-01 Online:2010-05-20 Published:2012-02-08
  • Contact: Shunping He

Abstract:

Based on the differences in caudal peduncle, snout length, predorsal profile and the lateral color pattern, Ng & Kottelat ( 2007) supposed that the currently recognized Pseudobagrus fulvidraco represent at least two distinct species, P. sinensis from northern China and P. fulvidraco from southern China. We examined the forenamed morphologic characters and sequenced the cytochrome bgene segments of 70 specimens to test the validity of P. sinensis. We found the differences in predorsal profile and the lateral color pattern do not occur together with the differences in caudal peduncle and snout length. Results of molecular phylogenetic and population genetic analyses were: (1) the most common haplotype detected was shared by P. sinensis and P. fulvidraco; (2) the reciprocal monophyly of both species was not confirmed whereas all samples of the two species were grouped in a monophyletic cluster with 100% bootstrap support; (3) gene flow is ongoing between populations of P. sinensis and P. fulvidraco (Nm = 4.7); and (4) the haplotype network did not detect any disjoint groups corresponding to the two species. We thus speculate that P. sinensis is not valid species but probably a synonym of P. fulvidraco. Low genetic divergence was detected among P. fulvidraco populations of China’s main river drainages, which was supposed to be resulted from a recent population expansion that occurred about 101,000-141,000 years ago. No significant geological architecture was detected from Chinese populations ofP. fulvidraco and the historical river connection might have promoted the gene exchange among different geological populations.

Key words: Pseudobagrus fulvidraco, Pseudobagrus sinensis, cyt b, genetic diversity, gene flow, population expansion