Genetic evaluation for body weight and survival of Pacific white shrimp (Litopenaeus vannamei) at different salinity

The purpose of the present study is to reveal the effects of different salinity on body weight and survival of families ofLitopenaeus vannamei. A total of 4348 shrimps from 72 families were raised for 60 d in the 30 salinity and 15 salinity environment. We analyzed the genetic parameters of body weight (BW) and survival rate, and genotype by environment interaction (G×E) ofL. vannamei at the 30 and 15 salinity. The results showed that at the 30 salinity, both the average body weight and survival rate were higher than those at the 15 salinity. In this study, the heritabilities of BW at the 30 and 15 salinity were (0.51±0.08) and (0.30±0.07), respectively, which were all high. After conversion, the heritabilities of survival were 0.22 and 0.39, which varied from medium to high. After integrating the data in the 30 and 15 salinity, the heritability of BW and converted heritability of survival were (0.45±0.07) and 0.31, respectively, which were both high. The estimates of genetic parameters might be over-estimated because the common environmental effect was not included in the estimation model due to convergence problem. The results showed there were high genetic correlations (0.81–0.90) for BW and survival between the two salinity. Ratios of G×E variance to additive genetic variance were all less than 0.5, G×E effects for BW and survival were not significant. These results suggested that although there were differences in growth and survival for families ofL. vannamei between the 30 and 15 salinity, the G×E was not significant and re-ranking effect was low. Therefore, there is no need to establish a separate breeding line ofL. vannamei for each salinity from 15 to 30 salinity environment.