Spatial correlations of transferrin allele frequencies in Atlantic salmon (salmo-salar) populations from north-america

Existing analyses of spatial patterns of transferrin (Tf) allele frequency variation in anadromous Atlantic salmon (Salmo salar) from rivers in North America have not utilized all available data. Further analysis shows that a latitudinal dine in Tf-4 allele frequency previously reported is an artefact of a major regional difference between populations from Newfoundland/Labrador and those sampled elsewhere. Furthermore, the allele frequencies of populations outside Newfoundland/Labrador show a significant association with the proportion of spawning fish in the populations having spent only one winter at sea. Fequencies in Newfoundland/Labrador are collectively consistent with this relationship but by themselves show no similar correlation. These results, combined with previously reported differences between anadromous and nonanadromous fish, suggest that selective forces, which vary with life history pattern, may operate on the polymorphism.