Abstract: Perinereis aibuhitensis is used as biological subject in acute toxicity test, for determining the 96 h-LC₅₀ of tetrabromodiphenyl ether(BDE-47).On this basis, the activities of SOD,CAT,GST,GPx and the contents of GSH, MDA of the antioxidant defense system of Perinereis aibuhitensis exposed to 0,2,4,8 mg·L^-1 of BDE-47 pollutants were determined. The results were as follows:the 96h-LC₅₀ of BDE-47 to Perinereis aibuhitensis was 31.24 mg·L^-1.Compared with the control group, the content of GSH and activities of GST and CAT had basically no significant change, only the GST activity of 8 mg·L^-1 group was significantly higher (P<0.01) on 14 th day.The GPx activity of 4 mg·L^-1 group was significantly higher (P<0.05) on 1 th day, and 2 mg·L^-1 group showed the increasing trend during the 7 th to 14 th day.On 1 th day, the SOD activity of the 4 mg·L^-1and 8 mg·L^-1 groups significantly decreased (P<0.05).Overall, during the period of 1-7 d, SOD activity of the 2 mg·L^-1, 4 mg·L^-1groups were induced to rise. On 14 th day, SOD activity in 4 mg·L^-1, 8 mg·L^-1 groups were significant (P<0.05) and significantly (P<0.01) inhibited respectively. The MDA content of all the treatment groups were induced to increase (P<0.05), and 4 mg·L^-1 group significantly increased (P<0.01) on 1 th day. There was no significant change in the content of MDA of the treatment groups during the exposure period of 4-14 th day, only 8 mg·L^-1 group was significantly higher (P<0.05) on 7 th day.In conclusion:the content of MDA and activity of SOD of the antioxidant defense system of Perinereis aibuhitensis had significant changes at the early exposure stage (P<0.05), which could be used as potential biomarkers.

Key words: Perinereis aibuhitensis, BDE-47, antioxidant enzyme, GSH, MDA, biomarker