Effects of Sudden Drop in Salinity on Activities of Antioxidant Enzymes of Litnpenaeus vannamei

The activities of CAT,SOD,AKP,ACP and the content of MDA of Limpenaeus vannamei were analyzed after the sudden drop in salinity.The results show that the activities of CAT,SOD,ACP,AKP and the average content of MDA were 0.004 40—0.005 54 U/mgport、0.837—0.908 U/mgport、0.002 08—0.002 43 U/gport、0.000 671—0.000 706 U/gport and 0.467—0.515μmol/L when the salinity dropped from 12 to 8,while the activities of CAT,SOD,ACP,AKP and the average content of MDA were 0.004 14—0.005 54 U/mgport、0.777—0.908 U/mgport、0.001 69—0.002 43 U/gport、0.000 641—0.000 706 U/gport and 0.467—0.806μmol/L when the salinity dropped from 12 to 5.These indicate that the activities of antioxidant enzymes of the Litnpenaeus vannamei were remarkably changed by sudden drop in salinity,and its disease resistance also decreased.