Sublethal effects of cadmium on energy reserves in the edible Mollusk Donax trunculus

Abstract

Cadmium (Cd) is one of the most toxic metals for marine organisms. The current experiment aimed to test two sublethal concentrations (LC10 and LC25-96h) of Cd on the main gonad components (carbohydrates, lipids, proteins) of an edible Mollusk Donax trunculus L. (Bivalvia, Donacidae). The samples were collected at El Battah a relatively clean site, during the reproduction period of the bivalves, and reared under laboratory conditions. Physico-chemical parameters of water such as temperature, pH, salinity, and dissolved oxygen were measured during the exposure period. The amount of biochemical components was determined at different exposure times (0, 24, 48, 72 and 96h) for both sexes. Our results revealed that female gonads are richer in energy reserves than males, and Cd caused a significant decrease in proteins and carbohydrates levels in both sex. Moreover, Cd reduced the lipid levels only in females. In fact, the effects of Cd are more pronounced in females as compared to males. A three-way ANOVA indicated significant effects of concentration, time and sex for each biochemical component.