Correlation between two size classes of pacific white shrimp Litopenaeus vannamei and its potential implications for selective breeding programs

The correlation between market weight (20-25 g) and broodstock weight (> 35 g) in Pacific white shrimp Litopenaeus vannamei has not been determined. Breeders may assume that the largest broodstock shrimp were also the largest market shrimp. In this study, 120 market shrimp were individually tagged and grown to broodstock in an earthen pond. There was a significant relationship between market and broodstock weight (P < 0.001) but it was not highly correlated (r = 0.42). There was no correlation between market weight and post-market weight gain (P = 0.477; r = 0.08). Of the largest 20 broodstock, only seven were among the top 20 at market weight. If the goal of a breeding program is to select the fastest growing individuals to market, shrimp should be individually selected at market weight and not as broodstock.