Bioaccumulation and toxicity of selenium in Chironomus decorus larvae fed a diet of seleniferous Selenastrum capricornutum

Abstract

The bioaccumulation and toxicity of selenium in a simple aquatic food chain was investigated by feeding a diet of seleniferous algae (Selenastrum capricornutum) to fourth instar midge (Chironomus decorus) larvae. Treatment diets consisted of S. capricornutum cultured in three concentrations of selenite (0, 10, and 40 μg Se/L) and four concentrations of selenate (0, 4, 10, and 40 μg Se/L). The seleniferous algae was freeze-dried and utilized as a diet for the midge larvae. The data show that, under laboratory conditions, a 96 h dietary exposure of ⩾2.11 μg Se/g dry weight significantly reduced larval growth at tissue concentrations ⩾2.55 μg Se/g dry weight. The results demonstrate that some invertebrates are very sensitive to dietary selenium exposure. When compared to similar studies with Daphnia magna, the data suggest that invertebrate primary consumers differ in the metabolism of dietary selenium.