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. B reeders may assume that the largest broodstock shrimp were also the largest market shrimp. In this study, 120 market shrimp were individually tagged a nd grown to broodstock in an earthen pond. There was a significant relation ship 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 breed ing program is to select the fastest growing individuals to market, shrimp should be individually selected at market weight and not as broodstock.