Migrations as a reason for genetic homogeneity of pacific herring (Clupea pallasii) from the Sea of Okhotsk

Abstract

Using parameters of molecular variability, calculated on the basis of comparison of mitochondrial DNA (mtDNA) control region sequences, no differentiation between samples of spawning herring from different regions of Sea of Okhotsk was found (p > 0.05). The absence of differentiation can be attributed to a permanent gene flow between schools, and it is possible to establish the value of the flow of migrants (Nm) only indirectly. Analysis of total molecular variability (global AMOVA) demonstrated that, when combining all studied samples or when pairwise uniting them, the intersample component accounts for approximately 0.1–0.2% of polymorphism with a high level of significance (p > 0.1); it can be considered a consequence of the influence of intense migrations. When estimating the minimal portion of migrants, it was determined that their amount is 3.6–9.5% per year by locality.