| 论文摘要： |
Optimizing stocking density and increasing shelters have been thought as strategies to enhance the performance of crayfish culture. In this study, indoor controlled experiments were carried out to determine the effects of different levels of stocking density (i.e., 50, 100 and 150 ind..m(-2)) and artificial macrophyte coverage (i.e., 20%, 50% and 80%) on the survival, growth and molting of juveniles of red swamp crayfish (Procambarus clarkii). A total of nine treatments with four replications were conducted simultaneously in 36 aquariums. No significant interactions were found between stocking density and artificial macrophyte coverage (P > 0.05). The crayfish yield (total biomass, TB) at 150 ind..m(-2) was significantly higher than that at 50 or 100 ind..m(-2) (P < 0.05), while higher stocking densities showed negative effects on the growth. A stocking density of 50 ind..m(-2) led to a significantly higher survival rate (SR), total weight gain (TWG) and mean molting frequency (MMF) (P < 0.05), and the specific growth rate of weight (SGRw) at 50 and 100 ind..m(-2) was significantly higher than that at 150 ind..m(-2) (P < 0.05). The rates of cheliped injury (CIR) and shelter occupancy (SO) were not significantly correlated to stocking density. Artificial macrophyte coverage had no significant effect on the SR or CIR, while the TB and MMF at 80% coverage were significantly higher than those at 20% coverage. The TWG, SGRw and SO (daylight) at 50% and 80% coverage were significantly higher than those at 20% coverage. Overall, these results indicate that, under improved culture conditions, a stocking density of around 50 ind..m(-2) and around 50% coverage of artificial shelter can be optimal for indoor culture of juvenile P. clarkii. |
