Estimates of genetic parameters for growth traits of the sea urchin, Strongylocentrotus intermedius

Heritabilities and genetic and phenotypic correlations were estimated for body weight, test diameter, and test height of the sea urchin from measurements on progeny resulting from 11 sires and 33 dams by artificial fertilization of 3 females by single males, and measurements at 8, 10, and 12 months after metamorphism. Point estimate for heritabilities based on the sire components of variance were moderate to high for body weight (0.21-0.49), test diameter (0.21-0.47), and test height (0.22-0.37). Genetic correlations were significant for body weight with test diameter (0.30∼0.65) and test height (0.30∼0.54) and test diameter with test height (0.31∼0.65). Genetic correlation estimates, derived the nested design and half-sib correlation analysis used in this study, appear to provide reliable estimates. Significant phenotypic correlations were found for body weight with test diameter (0.82∼0.86) and test height (0.49∼0.83), and test diameter with test height (0.47∼0.84). The phenotypic correlations for test height with body weight (0.491) and test diameter (0.467) at 12 months' of age were smaller than those earlier sampling periods.