Effect of gradual cooling on enzyme activity of Manila clam Ruditapes philippinarum with zebra－colored shell and different sizes
LI Jie1， SUN Xi－man1， ZHANG Peng1， YUAN Hong－mei1， WANG Ye1， YAN Xi－wu1，2， YANG Feng1，2
1.College of Fisheries and Life Science， Dalian Ocean University， Dalian 116023， China； 2.Engineering Research Center of Shellfish Culture and Breeding in Liaoning Province， Dalian 116023， China
Abstract: Digestive enzyme activities including amylase(AMS)，lipase(LPS)and pepsin and antioxidant enzyme activities including superoxide dismutase(SOD)and catalase(CAT)were determined in Manila clam Ruditapes philippinarum with zebra－colored shell， as a new variety， with shell length of 8 mm，13 mm， and 17 mm in a laboratory at initial water temperature of 8.2℃(as control)at a cooling rate of 1℃per 3 days(5.4℃，2.2℃，and 0.2℃)in order to investigate the tolerance of Manila clam to low temperature and its mechanism in winter.The results showed that there was no significant difference in mortality(less than 3%)among different groups.The AMS was shown to be induced by low temperature，especially in the juveniles with shell length of 8 mm，and lipase and pepsin activities were not detected.Under low temperatures， SOD activity was shown to show a first induction－then inhibition tendency in the juveniles with shell length of 8 mm and 13 mm and a tendency of first induction－then inhibition－again induction in the juveniles with a shell length of 17 mm，wholly induction tendency.At water temperature of 0.2℃，the activity of SOD was increased with the increase in juvenile size.Low temperature led to inhibitory effect on CAT activity in juveniles with a shell length of 17 mm and induction－inhibition effect on juveniles with shell length of 8 and 13 mm.There was higher inhibition CAT activity temperature(5.4℃)in the juvenile with shell length of 8 mm than that(2.2℃)in the juvenile with shell length of 13 mm and 17 mm，with decrease in the CAT activity at 0.2℃ with the increase in the clam size.Compared with CAT，SOD was primarily response for resistance to oxidative damage in juvenile clam exposed to low temperatures.The findings will provide a reference for understanding of the mechanism of low temperature tolerance and breeding.
李杰, 孙溪蔓, 张鹏, 袁洪梅, 王晔, 闫喜武, 杨凤. 渐变低温对不同规格菲律宾蛤仔斑马蛤酶活性的影响[J]. 大连海洋大学学报, 2018, 33(2): 217-222.
LI Jie, SUN Xi－man, ZHANG Peng, YUAN Hong－mei, WANG Ye, YAN Xi－wu, YANG Feng, . Effect of gradual cooling on enzyme activity of Manila clam Ruditapes philippinarum with zebra－colored shell and different sizes. Journal of Dalian Ocean University, 2018, 33(2): 217-222.
2018, Vol. 33 
