Accumulation and Depuration of Copper and Zinc in the Freshwater Mussel Cristaria plicata (Leach) under Laboratory Conditions

Accumulation, depuration and distribution of copper and zinc in the different soft tissues of the freshwater mussel Cristaria plicata (Leach) was studied under laboratory conditions with short term exposure in high concentrations. The results showed that the mussel had an ability to accumulate copper and zinc from the heavy metal polluted water and depurate them when transferred into clear water, with higher rate of accumulation than depuration. Different levels and rates of accumulation and depuration in soft tissues including gill, viscera, mantle, and the total soft tissue and the maximum in gill were found, this might be due to different mechanisms of metal binding and regulation of the soft tissues. At the end of deputation, Culevels in soft tissues of C. plicata were 2-5 times higher than before exposure, while Cu levels in soft tissues were almost similar to levels before exposure, which indicates that C.plicata is a potential biomonitoring organism of Cu contamination in freshwater. The distribution of Cu in soft tissues of the mussel suggests that gill is better for the monitoring of Cu contamination than the other soft tissues and the total soft tissues.