Effects of desiccation and resubmersion on oxidative stress response of crayfish (Procambarus clarkii)

In order to study the effects of desiccation stress on crayfish (Procambarus clarkii) during crayfish seedling transportation, we investigated the antioxidant stress ability and survival rate of crayfish to desiccation stress (6 h, 12 h, 18 h, 24 h) and resubmersion in water (1 h, 6 h, 12 h) at (20±1) ℃ and with (50±5)% relative humidity (RH). The results show that the desiccation time should not exceed 18 h; the mortality rate at 24^th hour was 53.3%, but no juveniles died during the resubmersion. During desiccation, no significant difference was observed in total antioxidant capacity (T-AOC, P>0.05); the superoxide dismutase (SOD) significantly reduced; the catalase (CAT) activity increased with time; the malondialdehyde (MDA) content reached the maximum value after 24 h (P<0.05), and the blood sugar and muscle lactic acid increased significantly with time (P<0.05). During the resubmersion period, the SOD and CAT activities fluctuated without an obvious rule; the MDA content restored to normal level after 12 h but the T-AOC maintained a high level. The lactate contents of 6 h and 12 h groups restored to the control level after resubmersion for 1 h. The blood sugar contents of all treatment groups were always higher than that of the control group (P<0.05). It is shown that the MDA content and SOD activity which can be regarded as immune indices are more sensitive to desiccation stress. The MDA, blood sugar and lactate contents can reflect the physiology of crayfish during resubmersion period.