Effect of Stocking Density on Growth, Oxidative Stress and HSP 70 of Pacific White Shrimp Litopenaeus vannamei

The objective of this research was to evaluate the growth, oxidative stress and HSP70 of pacific white shrimp under different stocking densities. Juvenile shrimps (average weight 2 g) were stocked under three densities (30,40,50 ind/cage, expressed as S30, S40 and S50 respectively) for 60 days. All treatment groups setting in net cages (size 40 cm x 40 cm x 40 cm) were submerged in a pond to ensure the same rearing conditions. At the end of the experiment, the survival rate decreased with increasing stocking density, ranged 83.3%, 79.2% and 78.7% respectively. The finial average size of shrimp in S30 was higher than that of the group S50. SGR, WG and FCR of shrimps in S30 group were better compared to that of the S40 and S50. Furthermore, antioxidant abilities in the hemolymph, hepatopancreas and muscle of shrimp were higher at low stocking density. HSP70 increased in hepatopancreas with increasing stocking density. The results of this study demonstrated that, when juvenile shrimps were reared under high stocking density, growth, feed utilization, antioxidant capability and stress resistance ability was decreased, indicating that high stocking density would affect growth and welfare of juvenile white shrimp.