Biochemical Changes in Chinese Pond Mussel Anodonta woodiana Following Exposure to Copper

We evaluated the potential utility of biochemical parameters as indicators of exposure to water-borne copper (Cu) in the freshwater mussel Anodonta woodiana. Semi-static renewal tests showed that the 96 h median lethal concentration of Cu was 3.4 mg/L (95% confidence interval [CI]: 2.1-6.5 mg/L) for juveniles and 22.1 mg/L (CI: 13.8-28.6 mg/L) for adult A. woodiana. In vivo bioassays were performed to determine the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and the levels of glutathione (GSH) in the adductor muscle, foot, gill, mantle, and visceral mass of A. woodiana after 48 and 96 h of exposure to Cu concentrations of 0.125 and 0.25 mg/L for juveniles, and 0.75, 1.5, 3 mg/L for adults. The levels of the lipid peroxidation product, malondialdehyde (MDA), were evaluated in five adult tissues. Our results indicated that SOD and CAT activity, and GSH levels in juvenile mussel foot and adductor muscle of adults might be sensitive to Cu exposure. This antioxidant defense system (CAT, GSH) was significantly enhanced in the mantle of juvenile mussel exposed to 0.25 mg Cu/L. The effect of Cu on the foot and mantle of juveniles, and the adductor muscle of adults seemed to be directly correlated with the levels of reactive oxygen species and antioxidant defense system components. Our data suggest that the biochemical responses (SOD and/or CAT, GSH) in the foot and mantle of juveniles, and the adductor muscle of adult A. woodiana might be good biomarkers of Cu contamination.