CYTOPATHOLOGICAL INVESTIGATIONS OF DIGESTIVE-TRACT AND STORAGE-CELLS IN DAPHNIA-MAGNA EXPOSED TO CADMIUM AND TRIBUTYLTIN

Histopathological effects on the ultrastructural organization of digestive tract and storage cells of Daphnia magna were examined after a 7-day exposure to cadmium or tributyltin chloride. No distinct cytological changes were noticed in the above-mentioned tissues of D. magna exposed to 10 μg Cd/l. In animals exposed to 20 μg Cd/l, however, there was a slight decline in the glycogen content of the storage cells and some structural changes in the mitochondria of these cells. By contrast, in daphnids exposed to 1 or 5 μg TBTC/l the ultrastructural integrity of storage cells appeared to be seriously affected. In addition, conspicuous lipid accumulations were observed in posterior gut epithelium and in a specific haemolymphatic cell-type of TBTC-exposed D. magna. The results of this histopathological investigation are discussed within the framework of our toxicity studies on the effects of cadmium exposure in Daphnia. © 1990.