HERITABILITY ESTIMATES OF LARVAL SHELL LENGTH IN THE CHILEAN BLUE MUSSEL MYTILUS-CHILENSIS, UNDER DIFFERENT FOOD DENSITIES

Heritability of larval growth rate in diferent food environments and g enotype-food environment interaction (during larval growth) are estima ted in Mytilus chilensis, based on a nested design, involving 24 full- sib families (8 males each mated to 3 separated females) grown under t hree different algal concentrations. The heritability estimates for la rval shell length ranged between 0.2+/-0.1 and 0.9+/-0.3 and showed a decreased towards the low food treatment; but the values suggest that selection would be effective. However, since there is a significant ge notype-food interaction, selection should be done in each environment in which the animals are expected to perform. The significant interact ion term (p<0.001) associated with a significant genetic variability f or larval growth suggest the presence of genes in the population whose expression depends upon local food conditions.