Abstract:This study analyzed the effective growth, non-specific immune function, and water quality required for juvenile shrimps of Fenneropenaeus chinensis (initial weight, 0.08 g) at four stocking densities of G0 (250 ind./m3), G1 (500 ind./m3), G2 (1000 ind./m3), and G3 (2000 ind./m3) during a 40-d indoor culture experiment. The results showed that the survival rate and growth index of G1 and G2 at 20 d were not significantly different from those of G0 (P>0.05), while the survival rate and growth index of G3 was significantly lower than those of G0 (P<0.05). At 40 d, the growth index and survival rate of G1 was significantly lower than G0 (P<0.05) The growth index of G2 was significantly lower than G0 (P<0.05), while G2 the survival rate was extremely significant different from G0 (P<0.01). And the growth index and survival rate of G3 was extremely significant different from G0 (P<0.01). Measurement of the antioxidant status in the serum, hepatopancreas, gill, and muscle tissue showed that the total antioxidative capacity, superoxide dismutase, hydrogen peroxide, and glutathione peroxidase first increased and then decreased with increase in density. At 20 d, the four oxidation indices were significantly higher in G1 and G2 than in G0 (P<0.05), and at 40 d, the indices were significantly lower than those in G0 (P<0.05). The content of malondialdehyde (MDA) increased gradually with increase in density; the MDA of G3 was always significantly higher than that of G0 (P<0.05). The MDA of G1 and G2 was significantly higher than that of G0 in hepatopancreatic tissue at 40 d (P<0.05), and was not significantly different from that in the other tissues (P>0.05). The pH, DO, NO2-N, NO3-N, NH3-N, and COD had no significant effect on the main water quality indices (P>0.05) at different densities, which were all within the suitable range for the growth of F. chinensis. The results showed that density stress significantly affects the growth and antioxidant capacity of F. chinensis, and the suitable densities were 1000 ind./m3 for 20 d and 250 ind./m3 for 40 d.
