Abstract: The mtDNA Cyt b gene of Siniperca scherzeri Steindachner from the upper reaches of Qiantang River (Jiangshan population and Wuxijiang population) and the upper reaches of Oujiang River (Yunhe population) were amplified and sequenced to assess the genetic diversity and genetic structure. The results showed that the average content of A+T (52.11%) was higher than that of G+C (47.89%) in the aligned 965 bp partial sequences. A total of 16 polymorphic sites were detected and 8 haplotypes were recovered out of 77 individuals. The haplotype diversity of Jiangshan, Wuxijiang and Yunhe populations were 0.570±0.078, 0.668±0.067 and 0.667±0.032,respectively, while the nucleotide diversity of the three populations were 0.001 8±0.000 3、0.001 9±0.000 2、0.004 3±0.000 6,respectively. The Fst value between Jiangshan population and Wuxijiang population was low (Fst=-0.005 16, P>0.05), which indicated that the two upper reaches of Qiantang River populations did not have significant genetic differentiation. While statistically significant genetic differentiations were observed between Yunhe population and Jiangshan population (Fst=0.191 23, P<0.01), and between Yunhe population and Wuxijiang population (Fst=0.178 10, P<0.01), which indicated significant genetic differentiations between the upper reaches of Qiantang River and the upper reaches of Oujiang River.

Key words: Siniperca scherzeri Steindachner, cytochrome b gene, genetic variation