Intraspecific Differentiation of Asian Pink Salmon Inferred from the Mitochondrial cytb Gene Sequences

The study is focused on intraspecific genetic polymorphism of pink salmon. The uniqueness of this representative of the Pacific salmon of the genus Oncorhynchus lies in the existence of two allochronic reproductively isolated groups, i.e., lineages that spawn either in even years or in odd years. In this study, for the first time, the variability of the mitochondrial cytochrome b gene (cytb) in all main regions of the Russian Far East was examined. Clear genetic differentiation between the lineages was demonstrated, while within the lineages, no stable interregional and temporal differences were found. The haplotype diversity within the even-year lineage considerably exceeded that within the odd-year lineage, and the genetic differences between the even-year and odd-year pink salmon exceeded the interpopulation variability within each of the lineages.