Intraspecies structure of the pacific herring <Emphasis Type="Italic">Clupea pallasii</Emphasis> valenciennes, 1847 (Clupeidae: Clupeiformes) in the Sea of Japan and the southern Sea of Okhotsk inferred from the variability of mitochondrial DNA control

The differentiation of local herring populations from the Sea of Japan and the southern Sea of Okhotsk was assessed on the basis of mtDNA (mitochondrial DNA) control region variability. Three samplings of sea herring and one sampling of lake herring were studied. The genetic analysis showed a significant (P < 0.01) difference between lake and sea herring samplings and no differentiation among sea samplings (P > 0.05). AMOVA analysis revealed that only 4.11% of the variability was attributed to the interpopulation component, while variability within populations was 95.89%. It is suggested that the reason for the weak differentiation of local sea herring populations may be an intensive gene flow.