We resolved allozyme variation among 28 enzymes encoded by 58 protein loci in 27 samples of sockeye salmon and kokanee Oncorhynchus nerka in the Pacific Northwest. Of 32 polymorphic loci, 16 were polymorphic at the P0.95 level (frequency of the common allele ≤0.95). We found substantial variation at mAAT‐1* and mAH‐1,2*, loci not previously described in O. nerka in this portion of its distribution. Mean heterozygosity per sample ranged from 0.010 to 0.036 and averaged 0.028 over all samples. Wrightˈs fixation index (FST) averaged 0.153 over 16 P0.95 loci, indicating considerable allele frequency variation among samples. The pattern of population differentiation of sockeye salmon, as revealed through genetic distance and principal component analyses, resembled a mosaic in that nearest geographic neighbors were not necessarily similar genetically. Allele frequencies at two to five loci differed significantly between sympatric sockeye salmon and kokanee in three separate localities, indicating genetic and reproductive distinctiveness of the two sympatric forms. Sockeye salmon from Redfish Lake (Sawtooth Valley, Idaho) were of particular interest because of their extensive freshwater migration and extremely low abundance in recent years. We found no evidence that any of the recorded stock transfers of O. nerka into the Sawtooth Valley (Redfish and Alturas lakes) have had a genetic impact on populations surveyed here. The O. nerka from Sawtooth Valley presently occupy a distinctive position in multilocus space, particularly with respect to mAH‐1,2*, mAAT‐l *, and ALAT*. Continued studies of O. nerka in the Sawtooth Valley are focusing on juvenile outmigrants and “residual” sockeye salmon.
A three-agency program was initiated in 1989 to develop a new multilocus genetic baseline for chum salmon (Oncorhynchus keta) in Japan and Russia for use in stock identification; allele frequencies at 77 allozyme loci are reported in 38 samples covering most of its north–south limits of distribution in Asia. In a 62-locus data set for 17 Japanese and 12 Russian samples, average heterozygosity ranged from 0.066 to 0.087 (mean 0.079) and the average number of P0.95 and P0.99 loci was 14 and 26, respectively. Tests of year-to-year variation in allele frequencies were not significant at five of six locations. For the P0.95 loci, FST values ranged from 0.007 (sMDH-B1*) to 0.154 (mAAT-2*) and averaged 0.038. A clear distinction between Russian and Japanese samples was observed at Nei's D = 0.006, and genetic differentiation generally followed a regional pattern within each country. Principal component analysis of the P0.95 loci revealed a large difference between Japanese and Russian samples. Four loci (sAAT-1,2*, mAAT-2*, LDH-A1*, and PEPLT*) had high loadings on the first two principal components. Analyses of a simulated fishery with 200 fish revealed a high degree of precision in estimating contributions to seven population groups and to country of origin.
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