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

Abstract:

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.