Electrophoretic Characterization of Odd-Year Pink Salmon (Oncorhynchus gorbuscha) Populations from the Pacific Coast of Russia, and Comparison with Selected North American Populations

Abstract

We collected and electrophoretically analyzed a total of 558 fish from eight locations along the Pacific Coast of Russia. We successfully screened 44 enzyme-coding loci: 14 loci were polymorphic at the 0.95 level in at least one collection, an additional eight were polymorphic at the 0.99 level but not at the 0.95 level, and the remaining 22 were either monomorphic or exhibited only very rare variation in these collections. Contingency χ2 tests using the 23 most variable loci revealed significant heterogeneity among all eight collections (p = 0.028) but little or no significant heterogeneity among collections within areas (northeastern Kamchatka peninsula, p = 0.180; southwestern Kamchatka, p = 0.533; and mainland adjacent to the northwestern Sea of Okhotsk, p = 0.071). Multidimensional scaling and minimum spanning tree analyses using genetic distances among collections indicated that geographic proximity of spawning sites was not associated with genetic similarity. The eight odd-year pink salmon (Oncorhynchus gorbuscha) collections from Russia were compared with 16 collections from North America (southeastern Alaska, British Columbia, and Washington) using data for 33 loci. The Russian populations differed from the North American populations in their patterns of allelic variation at many loci. The amount of genetic differentiation among populations from different rivers in Russia was comparable to that seen within similar-sized areas in North America.