温度胁迫对银鲳(Pampus argenteus)幼鱼消化酶活性及血清生化指标的影响

分别在22、27(对照组)、32℃的水环境中，对银鲳(Pampus argenteus)幼鱼进行急性温度胁迫48 h，检测不同时间、不同温度下银鲳幼鱼肠道消化酶活力及血清生化指标。结果显示，肠道消化酶中，胃蛋白酶和胰蛋白酶的活力在22℃实验组没有显著变化(P>0.05)，淀粉酶活力逐渐下降，脂肪酶活力则相反(P<0.05)；在32℃实验组中，脂肪酶、胃蛋白酶、胰蛋白酶的活力变化基本一致，均呈现上升趋势(P<0.05)，而淀粉酶活力呈先升高后降低趋势；在血清生化指标中，葡萄糖(GLU)、乳酸(LD)、皮质醇(COR)在22℃实验组显著升高(P<0.05)，甘油三酯(TG)和肌酐(CREA)均呈现先降低后升高再降低的趋势(P<0.05)，血清总蛋白(TP)含量则呈先降低后升高趋势(P<0.05)。在32℃实验组中，TP 和 TG 含量降低；GLU 含量没有显著变化(P>0.05)；LD 含量呈先下降后上升的趋势(P<0.05)；COR 先上升后降低，而 CREA 则呈现上升趋势；在肠道和血清中不同处理组在同一时间也出现显著性差异(P<0.05)。研究表明，急性温度胁迫对银鲳幼鱼消化系统及排泄系统造成一定的影响。因此，在实际生产操作及工厂化养殖过程中，应尽量避免急性温度胁迫，减小银鲳幼鱼的应激反应，使其有良好的生活环境。

Effects of Temperature Stress on Activities of Digestive Enzymes and Serum Biochemical Indices of Pampus argenteus Juveniles

To investigate how temperature affects activities of digestive enzymes and serum biochemical indices of Pampus argenteus juveniles, in this study we tested their biochemical indices in experimental temperature groups (22℃ and 32℃), and the control group (27℃). P. argenteus juveniles were randomly assigned to three replicates in each group and reared for 48 h. In the 22℃ group, the activities of pepsin and trypsin in the gut showed no significant change (P>0.05). However, the amylase activity was decreased whereas the lipase activity was increased (P<0.05). In the 32℃ group, activities of lipase, pepsin, and trypsin were significantly enhanced (P<0.05), but amylase activity was first increased followed by a decline (P<0.05). In the 22℃ group, the contents of glucose (GLU) , lactic acid (LD) , and cortisol (COR) were raised (P<0.05); the levels of triglyceride (TG) and creatinine (CREA) showed a decrease-increase-decrease pattern (P<0.05); the content of total serum protein (TP) dropped first and then went up (P<0.05). In the 32℃ group, levels of TP and TG were decreased; no significant changes were observed in the GLU level (P>0.05); LD decreased first and then increased, whereas COR altered in an opposite way (P<0.05);the content of CREA was elevated. There were also significant differences in gut and serum between different experimental temperature groups at the same time point. These results indicated that the acute temperature stress might jeopardize the digestive and excretory systems of P. argenteus juveniles, therefore it should be avoided in the process of industrial aquaculture to improve the living condition of P. argenteus juveniles.