Population genetic structure and geographical differentiation of burbot (Lota lota) in China.

The burbot (Lota lota Linnaeus, 1758) is the only freshwater species of the family Gadidae. There is a long-standing controversy about taxonomic status of the burbot from the Amur River basin. It is necessary to investigate population genetic structure and geographical differentiation among burbot populations from the Irtysh River basin and Amur River basin by mitochondrial DNA nucleotide sequence analysis. A 572 bp segment of cytochrome b and 425 bp segment of control region gene were sequenced from 4 populations. The results showed that there was lower genetic diversity of burbot in China and highly significant genetic difference between populations in the Amur Riverbasin (P < 0.01). Demographic analysis indicated that the burbot from the Amur River basin experienced population expansion (Cytb: F(s) = -0.912 (P = 0.287), D = -0.399 (P = 0.375); CR: F(s) = -4.771 (P = 0.015), D = -1.523 (P = 0.03 )). The data of 4 populations in China combining with the published data representing the Eurasian and North American burbot, revealed three distinct phylogenetic lineages (labelled EB, NA, Amur).