Effects of pH Stress on Some Immune Factors of Mud Crab,Scylla paramamosain

The present experiment was conducted to determine the changes of the activities phenoloxidase(PO),total superoxide dismutase(SOD),lysozyme(UL) and antibacteria of Scylla paramamosain under pH(4.5,6.0,7.5,9.0 and 10.5) stress for 9 days by enzyme analysis.S.paramamosain were reared in close-cycle system for acclimation and then transferred to different groups.Each treatment was run in triplicate.The activities of those parameters were determined after every one day.The results showed that the activities of PO,SOD and antibacteria in haemolymph were increased significantly at different pH groups(p0.05),while UL activity change in haemolymph was not significant difference(p0.05),and total SOD activities in muscle and hepatopancreas were increased significantly(p0.05).Total SOD activities in hepatopancreas was increased significantly(p0.05) at the same pH group but in muscle and haemolymph were not significant changes(p0.05).In conclusion,the non-specific immunity of mud crab was significantly affected under pH stress.During pH7.5 to pH9.0 the non-specific immunity of S.paramamosain increased obviously.