Growth and performance of the whiteleg shrimp Penaeus vannamei (Boone) cultured in low-salinity water with different stocking densities and acclimation times

We evaluated the performance of whiteleg shrimp Penaeus vannamei (Boone, 1931) in response to different stocking densities and acclimation periods. Shrimp postlarvae were acclimated from seawater (30 g L-1) to low-salinity well water (< 1.0 g L-1) at a constant hourly reduction rate of 40, 60, 80 and 100 h. After acclimation to low-salinity well water, postlarvae from each acclimation time treatment were stocked in three replicate tanks at densities of 50, 100, 150 or 200 shrimps m-2 for 12 weeks of growth. Salinity averaged < 1.0 g L-1 for each growth study. The different treatments resulted in significant differences in both the final body weight and the survival rate (SR). Shrimp acclimated for 100 h showed substantially improved survival (83%) relative to shrimp acclimated for shorter periods. Shrimp yields for all cultured periods ranged from 0.32 kg m-2 in tanks stocked at 50 m-2 to 1.14 kg m-2 in tanks stocked at 200 m-2. We conclude that whiteleg shrimp can be successfully grown in low-salinity well water, and that the growth, production output and SRs are significantly higher when shrimp are acclimated for longer periods.