Abstract: Superoxide dismutase(SOD)and catalase(CAT)activities of juvenile razor clam Solen grandis with shell length of(1.33 cm±0.10 cm)were monitored at a salinity of 15,20,30 and 35 and pH of 7.0,7.5,8.5 and 9.0 for 0,4,12,24,48,72 and 96 h,respectively,in order to clarify the effects of salinity and pH on the antioxidant enzyme activities of juvenile razor clam.The results showed that there were significantly higher activities of SOD in the clam exposed to a salinity of 20 for 12 and 24 h and a salinity of 30 for 24 h than those in the control group(salinity 25)(P＜0.05).However,there were significantly higher CAT activities in the clam exposed to a salinity of 20 for 4 and 12 h and a salinity of 30 for 12 and 24 h than those in the control group(salinity 25)(P＜0.05),finally activities of both SOD and CAT being recovered to the control level in 48 h and 96 h.The razor clam exposed to a salinity of 15 and 35 from 48 h to 96 h had significantly higher SOD and CAT activities than those in controls(P＜0.05)did.The razor clam exposed to pH 7.5 and pH 8.5 from 12 h to 96 h had significantly higher SOD and CAT activities than those in control group did(pH 8.0,except pH 8.5 in 48 h)(P＜0.05).There was significantly higher SOD activity in the clam exposed to pH 7.0 and pH 9.0 than those in the control group at 12-96 h(P＜0.05),the activities of CAT being significantly lower from 72 h to 96 h(P＜0.05).The findings indicated that SOD and CAT activities in razor clam were affected by changes in salinity and pH,the razor clam being adaptable to sudden change in salinity within 20 and 30,and that the razor clam showed cellular oxidative damage induced by the pH 7.0 and pH 9.0 changes under the status of oxidative stress for a long period of exposure at a salinity of 15 and 35 and pH 7.5,and 8.5.The adaptive salinity and pH are suggested to should be kept in 20-30 and 7.5-8.5 for the culture of Solen grandis juveniles,respectively.
2017, Vol. 32 
