Inheritance of size as estimated by principal component analysis at two temperatures in Penaeus vannamei

Larvae and postlarvae from full-sib families of Penaeus vannamei were reared under controlled conditions in an experimental facility. Principal component (PC) analysis was performed on these data sets. Total length was used to estimate size. Analysis of postlarval growth used the first principal component score (PRIN1) for each individual which summarized the information on size inherent in the data set. PRIN1 scores and single variables were used in ANOVA to obtain estimates of heritability of size at each age under each temperature. Heritabilities ranged from 0.02 to 0.16 for size after larval growth and 0.0 to 0.59 for size after postlarval growth. Heritabilities were larger when shrimp were grown at 22-24 degree C.