Estimates of genetic parameters for growth and survival in pacific oyster (Crassostrea gigas)

Abstract

 The rapid growth associated with high tolerance to adverse environmental conditions has made the Pacific oyster, Crassostrea gigas, the species chosen for cultivation in Santa Catarina, Brazil. Variance components and genetic parameters for survival and growth of Pacific oyster families were estimated using data from half-sibs (n = 41) and full-sibs (n = 2) families. In the juvenile stage and at harvest, we measured total weight and shell height of 80 animals per family. In addition, at harvest we measured yield (total weight of animals per floor of lantern) and calculated survival. The covariance components were estimated in the program AIREMLF90 using an animal model.The heritabilities (Standard Deviation) at harvest were: 0.26 (0.05) (individual weight (SD)), 0.34 (0.05) (height), 0.54 (0.09) (yield), 0.58 (0.08) (average individual weight) and 0.16 (0.07) (survival). Genetic correlations were 0.88 (0.03) (between individual weight and height), 0.98 (0.03) (between yield and average individual weight), 0.58 (0.39) (between average individual weight and survival) and 0.47 (0.36) (between yield and survival). The heritability and genetic correlations suggest that gains could be obtained for the studied traits. The yield and mean individual weight should be used as a criterion for selection.