The antagonism between selenium and cadmium in a freshwater mollusc.

The protective effect of selenium against cadmium toxicity in rats is well documented. Data concerning such protection are lacking in invertebrates. The object of this study was to check whether such an antagonism between Se and Cd can be found in the freshwater mollusc Lymnaea stagnalis L. In the presence of sublethal amounts of selenium, sensitivity with respect to cadmium is nearly halved. Sublethal amounts of cadmium give additional protection against the toxic effects of selenium, since this concentration completely prevented mortality due to high doses of selenite (3 mg/L Se) and selenate (15 mg/L Se).