Genetic heterozygosity and meristic character variance in a wild Atlantic salmon population and a hatchery strain derived from it

Abstract

Heterozygosity at seven enzyme loci was compared with the degree of fluctuating asymmetry of three bilateral traits in a wild population of Atlantic salmon (Salmo salar L.) and a hatchery strain derived from it. In the wild population, average heterozygosity per fish was higher (p < 0.01) and average asymmetric value per fish was lower (p < 0.01), compared with the hatchery strain. Analyses at the intrapopulation level did not provide unequivocal support for the relationship between heterozygosity and developmental stability, with correlation between the number of heterozygous loci per fish and the asymmetric value per fish being non-significant. However, comparisons of asymmetric value per fish between homozygous and heterozygous individuals at separate loci indicated that heterozygotes had significantly lower asymmetry values per fish at IDDH-1* in the hatchery sample. These results are discussed in relation to the potential utility of fluctuating character asymmetry as an indicator of loss of heterozygosity in cultured Atlantic salmon stains.