scallops C. farreri were randomly divided into four groups: control group (XD) and CdCl2·2.5H2O treated groups (XA, XB, XC). The final Cd2+ concentration was 0.1 mg/L (20 times than the standard value of Cd 2+ = 0.005 mg/L) in XA group, 0.3 mg/L (60 times than the standard value of Cd 2+ = 0.005 mg/L) in XB group, and 1 mg/L in XC group. All the scallops were exposed to cadmium for consecutive 15 days.