BIOACCUMULATION AND TOXICITY OF SELENIUM IN CHIRONOMUS-DECORUS LARVAEFED A DIET OF SELENIFEROUS SELENASTRUM-CAPRICORNUTUM

The bioaccumulation and toxicity of selenium in a simple aquatic food chain was investigated by feeding a diet of seleniferous algae (Selena strum capricornutum) to fourth instar midge (Chironomus decorus) larva e. Treatment diets consisted of S. capricornutum cultured in three con centrations of selenite (0, 10, and 40 mu g Se/L) and four concentrati ons of selenate (0, 4, 10, and 40 mu g Se/L). The seleniferous algae w as freeze-dried and utilized as a diet for the midge larvae. The data show that, under laboratory conditions, a 96 h dietary exposure of gre ater than or equal to 2.11 mu g Se/g dry weight significantly reduced larval growth at tissue concentrations greater than or equal to 2.55 m u g Se/g dry weight. The results demonstrate that some invertebrates a re very sensitive to dietary selenium exposure. When compared to simil ar studies with Daphnia magna, the data suggest that invertebrate prim ary consumers differ in the metabolism of dietary selenium.