干露胁迫对四角蛤蜊存活率与生理生化指标的影响OA

In order to investigate the effects of exposure to air on survival rate,physiology and biochemistry of Mactra veneriformis,study the stress response mechanism,and provide a scientific basis for seedling rear-ing and transporting.Using an indoor experimental ecological approach,we systematically examined the impact of different air exposure durations(0,24,48,72,96 and 120 h)on the survival rate,oxygen consump-tion rate,ammonia excretion rate,digestive enzyme activities,and protective enzyme activities in Mactra veneriformis.The study aimed to analyze the stress response mechanism and determine an appropriate safe air exposure duration.The results showed that:①survival rate progressively declined with increasing expo-sure duration.In contrast,oxygen consumption and ammonia excretion rates initially increased and subse-quently decreased.Within the exposure period,maintaining 100%survival(0-72 h),the oxygen consump-tion rate increased by 10%relative to the control after 5.7 h,and by 50%after 21.8 h.Similarly,the ammonia excretion rate increased by 10%after 0.7 h and by 50%after 3.7 h.② Following air exposure stress,the oxygen-to-nitrogen ratio(O∶N)was significantly lower than that of the control group(P<0.05).③With prolonged exposure,amy-lase(AMS)activity initially decreased and then increased,while lipase(LPS)activity first increased and then decreased.Catalase(CAT)and superoxide dismutase(SOD)activities exhibited a pattern of inhibition-induction-inhibition-induction.Acid phosphatase(ACP)activity displayed an inhibition-induction-inhibition pattern.In conclusion,air exposure stress significantly impacts survival rate,physiology,and biochemistry in Mactra veneriformis.To ensure clam vitality at 17-18℃,the air expo-sure duration should ideally not exceed 24 h,and must not exceed 72 h.