Genetics of Zoarces populations

A sample of 4206 adult eelpouts and 2210 fetal young, collected in the early part of the winter 1971–72 in Kaloe Cove, was analyzed for the action of zygotic, gametic and sexual selection in the brain esterase polymorphism, EstIII. The selection component analysis, which as an essential device makes use of genotypic mother-offspring combinations, was extended to embrace adult age groups as an additional factor not included in our earlier analyses. The new data confirm the previously observed deficit of heterozygotes, which develops between the late fetal and the adult stage, supposedly due to zygotic selection against the heterozygotes. Significant evidence was found of heterogeneity among gene frequencies in the male gametes transmitted through females of different age. This heterogeneity appears to result from a strong correlation between the ages of mates combined with the fact that zygotic selection alters the gene frequency in males as these grow older. Suggestive, but as yet statistically insignificant evidence of male reproductive selection is also presented.