Effects of dissolved oxygen on respiratory rate,physiological and biochemical parameter and tissue structure of Cynoglossus semilaevis
In order to understand the effects of dissolved oxygen changes on Cynoglossus semilaevis,which often occurs in circulating water culture systems with low and high oxygen,this experiment examined the effects of low dissolved oxygen(3 mg/L),control(8 mg/L),and high dissolved oxygen(14 mg/L,20 mg/L)conditions on the respiration,physiological and biochemical parameter,and tissue structure of Cynoglossus semilaevis.The results showed that respiratory rate increased significantly in the hypoxic group and decreased significantly in the hyperoxic group within 24 h(P＜0.05)At day 7,the respiratory rate of the low oxygen group was not significantly different from that of the control group(P＞0.05),while the respiratory rate of the high oxygen group decreased significantly with the increase of dissolved oxygen(P＜0.05).After the 14th day,the respiratory rate of the low oxygen group was not significantly different from that of the control group,while the respiratory rate of the high oxygen group decreased significantly with the increase of dissolved oxygen(P＜0.05).Both the hypoxic and hyperoxic groups showed proliferation of epithelial cell layers compared to the control group,and the gill tissue in the hyperoxic group showed more vacuolation than the control group in the Cynoglossus semilaevis.In the hypoxic group,liver tissue structure was abnormal,with extensive loose edema and unclear cell outline,while the hepatocytes in the hyperoxic group had clear outline and red stained cytoplasm,but no obvious degeneration was observed.The number of erythrocytes and hemoglobin content of blood in the hypoxic group increased compared with the control group(P＞0.05),and the ratio of erythrocyte volume decreased compared with the control group(P＞0.05).The erythrocyte count,hemoglobin content and erythrocyte specific volume were higher in the hyperoxia group than in the control group(P＞0.05).Plasma MDA content,SOD activity and CAT activity were significantly higher in the hypoxic and hyperoxic groups than in the control group(P＜0.05).In conclusion,both hypoxia and hyperoxia caused stress on Cynoglossus semilaevis,and the stress of hypoxia was more obvious on Cynoglossus semilaevis.
NETL
NSTL
万方数据
