Response to pH Stress of the Activities of ATPase and Phosphatase in Scylla paramamosain

With the method of enzyme analysis,we carried out the experiments for determining the changes of the ATPase and phosphatase activities in gill,muscle and hepatopancreas of Scylla paramamosain under varying pH(4.5,6.0,7.5,9.0 and 10.5) stress for 9 days,with the natural seawater(pH 6.76) as control.The results showed that the activities of Na+,K+-ATPase in gill increased significantly(p0.05) with pH stress intensity,whereas no marked changes(p0.05) in Ca2+,Mg2+-ATPase activities were observed,and both Na+,K+-ATPase and Ca2+,Mg2+-ATPase activities reached the peak value at the third day.The AKP activities in muscle were remarkably higher(p0.05) in control than that of the other groups.Nevertheless,the activities of AKP in hepatopancreas were lower in pH 4.5 group but slight higher(p0.05) in other groups in comparison with the control group.On the other hand,the muscle ACP activities in both pH 6.0,and pH 10.5 groups were markedly lower(p0.05) than that of the control group.Compared to the control,the ACP activities of hepatopancreas were significantly higher(p0.05) in pH9.0 and pH 10.5 groups but lower(p0.05) in pH 7.5 group.However,no significant difference(p0.05) was detected among the groups of pH4.5,pH 6.0 and the control groups.The ACP and AKP activities in both muscle and hepatopancreas varied irregularly with the pH stress time,but displayed an obvious time-effect.The present results suggested that pH stress significantly conditioned the physiological-biochemical parameters of Scylla paramamosain.