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Coilia ectenes is a commercially important fishery species. In this study, genetic diversity and population structure of C. ectenes were examined by using mitochondrial DNA control region sequences in 246 individuals sampled from 10 localities in China. One hundred and ninety-five polymorphic sites defined 184 distinct haplotypes, revealing a moderately high haplotype diversity (Hd) and a relatively low nucleotide diversity (π) in the 10 localities. An excess of unique haplotypes at most sample locations were detected, which might influence the genetic structure of the C. ectenes populations. Hd ranged from 0.939 to 1.000 and π ranged from 0.26% to 1.15%. The Dongting fish population had the highest π level. The genetic distances ranged from 0.26% to 1.03% within populations and from 0.56% to 4.90% between populations. The distances between the Fuzhou (FZ) population and other populations were mostly >4.8%. Neighbor-joining tree indicated distinct patterns of phylogeographic structure among haplotypes from FZ population and those from other populations. Analyses of molecular variance and Fst statistics suggested that the divergence existed among populations from 10 localities, indicating that gene flow might be restricted among those regions, despite the wide dispersal. In addition, neutral tests and analysis of mismatch distribution suggested that C. ectenes might have undergone a population expansion. Our study revealed the extant population genetic diversity and structure of the C. ectenes, and was in favor of the related fishery management issues including fishery stock identification and conservation. [ABSTRACT FROM AUTHOR]

Abstract: Coilia ectenes is an important commercial fisheries species. In this study, the genetic diversity and population structure of ten Chinese populations of C. ectenes were investigated using cytochrome b (cytb) sequences of mitochondrial DNA (mtDNA). We sequenced the complete cytb gene of 279 individuals. One hundred and eleven polymorphic sites defined 97 distinct haplotypes. Haplotype diversity (Hd) ranged from 0.6433 to 0.9517 and nucleotide diversity (π) ranged from 0.16% to 1.23%. The Wuhan (WH) fish population had the highest π level. The genetic distances ranged from 0.16% to 1.26% within populations and from 0.18% to 2.66% between populations. The distances between the Fuzhou (FZ) population and other populations were greater than 2%, while the distance between the Lianyungang (LYG) and Taihu Lake (TH) populations was the smallest. The fixation index analysis indicated that there was significant genetic divergence among populations from different geographical groups. Both the neighbor-joining tree and median-joining network analysis of the haplotype data showed distinct patterns of phylogeographic structure. The hierarchical analysis of molecular variance (AMOVA) revealed that intra-group variation among populations (θ SC) was highly significant. The results of this study suggest that C. ectenes populations, especially geographically isolated groups, have developed significant genetic structures. In addition, tests of neutral evolution and mismatch distribution suggest that C. ectenes may have experienced a population expansion, possibly in the past 110,000years. [Copyright &y& Elsevier]