Comparative Analysis on Mitochondrial Control Region DNA Diversity of Three Far Eastern Catfish (Silurus asotus) Populations

To investigate genetic diversity of the far eastern catfish (Silurus asotus) populations in the Yellow River, the Songhua River, and the Dayanghe River, mitochondria] control region (D-loop) DNA was analyzed for the samples collected in Zhengzhou (ZZ in the Yellow River), Haerbin (HEB in the Songhua River), and Donggang (DG in the Dayanghe River). There were totally twenty-one haplotypes identified in the three groups of samples. Haplotype networks by using neighbor-joining and median-joining clustering methods both indicated that the haplotypes 3, 8, and 19 constituted a single branch and the other 18 haplotypes constituted another branch. The highest genetic differentiation coefficients were observed between the ZZ and HEB samples (0.264), and the lowest was between the ZZ and DG (0.101). The average gene flow among the three populations was 3.063. The Fu's Fs and Tajima's D test values of the three populations were both negative, and indicated no significant difference between three populations (p=0.08 and 0.06> 0.05). Our results suggest that the far eastern catfish populations have not undergone significant population expansion and remained stable in the Yellow River, the Songhua River, and the Dayanghe River.