盐度胁迫对非洲斑节对虾生理特征的影响

为探讨不同盐度梯度下非洲斑节对虾(Penaeus monodon)的盐度耐受性,本研究测定了盐度胁迫下对虾生长、渗透、抗氧化及消化指标的变化.实验设置4个盐度梯度(20,30,40,50),以30盐度组作为对照,进行为期35 d的喂养实验.实验结束时计算增重率(Weight Gain Rate,WGR)、特定生长率(S...

Effects of Salinity Stress on Physiological Characteristics of Penaeus monodon

In order to explore the salinity tolerance of Penaeus monodoncv under different salinity gradients, the changes in shrimp growth, osmosis, antioxidant and digestive indexes under salinity stress were measured in this study. Four salinity gradients (20, 30, 40, 50) were set in the experiment, and the 30 salinity group was used as a control for a 35 d feeding experiment. At the end of the experiment, Weight Gain Rate (WGR), Specific Growth Rate (SGR) and Survival Rate (SR) were calculated. The activities of ATPase and Na⁺-K⁺-ATPase in the gill, activities of SOD, CAT, T-AOC, GSH-Px and content of MDA in the serum, pepsin, lipase and amylase in the hepatopancreas were measured. The results showed that the growth performance of P. monodon was inhibited under salinity stress, and the survival rate decreased with the increase of salinity. Compared with the control group, WGR and SGR were the lowest in the 50 salinity group, showing significant differences (P<0.05). When the salinity stress occurred, the total ATPase activity of prawns increased, and with the extension of time, it showed an adaptive state. On the 35^th day of the experiment, there was no significant difference between the salinity groups (P>0.05). While the activity of Na⁺-K⁺-ATPase in the 40 and 50 salinity stress groups was significantly higher than the control group (P<0.05). During the experiment, the degree of SOD change was small, and the difference was not significant compared with the control group (P>0.05). The activities of CAT, T-AOC, GSH-Px and the content of MDA were significantly different (P<0.05). Salinity stress stimulated the antioxidant stress ability of P. monodon. High salinity reduced the activities of pepsin and lipase in P. monodon, especially in 40 and 50 salinity stress groups (P<0.05). On the third day of the experiment, the activity of amyase in 20 salinity group was significantly increased (P<0.05), and activities of pepsin and lipase were decreased (P<0.05). The results showed that salinity stress was not conducive to the growth of P. monodon, but it could activate the antioxidant capacity, adjust its enzyme activity to adapt to environmental changes, and the digestibility of the shrimp to varying degrees, thus inhibiting the growth performance.