Divergent selection for growth rate in the European oyster Ostrea edulis response to selection and estimation of genetic parameters

Abstract

ABSTRACT: Individual (mass) selection for growth rate was carried out in the European oyster Ostrea edulis (Linne). Oysters from 40 families produced In 1983 were selected on the basis of their live weight after the first growing season. Divergent select~on was applied; the High and Low selected group were mated in pairs according to their rank. Twenty-four families were obtained: 6 Low selected and 18 High selected. A total of 6560 spat were individually tagged and brought to the field for 2 yr. Shell height and live weight after the first and second growing seasons were analyzed. Statistically significant &ffer- ences (p < 0.05) were found between the offspring of the High and Low selected groups for both traits after both growing seasons. No differences in survival were detected between the fam.ilies of the 2 selected groups. Heritability esbmates for live weight and shell height, after each growing season ranged from h* = 0.112 to 0.243. Genetlc correlations between the traits were found to be high; r, = 0.963 for the first growing season and ra=0.995 for the second growing season.