Effects of stocking density on the survival, growth and physical injury of Marsupenaeus japonicus juveniles in a flowing water aquaculture system

Stocking density is a biotic factor affecting the production of cultivated animals in aquaculture. Herein, a rearing trial was conducted to investigate the impact of stocking density on the survival, growth performance and physical injury of Marsupenaeus japonicus juveniles in a flowing water aquaculture system. Five stocking densities were examined in this study, that is, 10, 20, 40, 80 and 160 individuals/m(2). Throughout the experiment, ammonia nitrogen and nitrite concentrations ranged from 0.02 +/- 0.006 mg/L to 0.08 +/- 0.035 mg/L and 0.002 +/- 0.001 mg/L to 0.076 +/- 0.021 mg/L respectively. The survival rate, specific growth rate (SGR), weight gain (WG), absolute growth rate (AGR) and coefficient of variation for weight (CV) across the stocking densities ranged from 90.38 +/- 3.20% to 94.33 +/- 4.73%, 1.42 +/- 0.16%/day to 1.53 +/- 0.05%/day, 1.09 +/- 0.19 g to 1.15 +/- 0.16 g, 0.018 +/- 0.003 g/day to 0.019 +/- 0.004 g/day and 16.21 +/- 5.78% to 35.09 +/- 10.68% respectively. Within the investigated densities, the survival rate and the abovementioned growth parameters were not significantly (p > .05) affected by the stocking density, consequently, a higher stocking density resulted in a significantly (p < .05) greater final biomass. The results regarding physical injury showed that the antennal breakage rate displayed a tendency of a positive correlation with the stocking density. Overall, the current study provides basic data for establishing a viable intensive farming system for M. japonicus and a promising indicator for easily assessing the crowding stress status of M. japonicus.