关键词: 短颌鲚, 遗传多样性, 遗传结构, 汉阳地区湖泊

Abstract: To understand the genetic diversity of Coilia brachygnathus（C. brachygnathus） populations，a dominant fish species in the lakes of the Hanyang area，we analyzed genetic diversity，interpopulation differentiation，and historical population dynamics of four C. brachygnathus populations from the Sanjiao Lake，the Nantaizi Lake，the Longyang Lake， and the Houguan Lake. Mitochondrial Cyt b gene and D-loop sequences were employed as molecular markers. The results revealed high genetic diversity in C. brachygnathus populations from the four lakes，with haplotype diversity ranging from 0. 613 to 0. 868（Cyt b）and 0. 842 to 0. 929（D-loop），and nucleotide diversity was 0. 002 23- 0. 002 63（Cyt b）and 0. 004 90- 0.007 51（D-loop），all of which were at relatively high levels. Pairwise fixation index （F_ST） values suggested some genetic differentiation between the Longyang Lake population and other populations. Principal components analysis（PCA）and haplotype network analyses demonstrated a distinct phylogeographic structure among populations from the lakes in the Hanyang area. Neutrality tests and mismatch analysis indicated no historical population expansion events in C. brachygnathus populations from the lakes in the Hanyang area.

Key words: Coilia brachygnathus, genetic diversity, genetic structure, lakes in Hanyang area