HISTOPATHOLOGICAL EFFECTS AND BIOLOGICAL ACCUMULATION OF COPPER IN THE PERIWINKLE (Tympanotonus fuscatus var. radula).

Histopathological effects and bioaccumulation of copper in the periwinkle, Tympanotonus fuscatus var. radula was assessed in the laboratory for 30 days. Periwinkles were exposed to sub lethal concentrations (0.5, 1, 2, and 4 mg/l) of copper. The test was conducted using the Organization for Economic Cooperation and Development (OECD) protocol #218 in a sediment medium. There were three replicate plastic tanks per treatment and 6 periwinkles per tank. Control groups without copper were also prepared. T. fuscatus var. radula bioaccumulated copper. It was observed that bioaccumulation of copper in the periwinkle increased (p<0.05) with increase in concentration of the heavy metal. Histopathological changes were studied in the kidney and muscular foot of the T. fuscatus var. radula. In the kidney, periwinkle showed fatty change in all concentrations except control groups. Necrosis occurred in the 1 and 2 mg/l concentration. Hyperchromatic nuclei were observed in the lowest (0.5mg/l) and highest (4.0mg/l) concentrations. In the muscular foot, hyperinflation occurred only in the 0.5 mg/l exposure. Fatty change occurred in all concentrations. Hyperchromatic nuclei was manifested in the 1, 2 and 4.0mg/l concentrations with increasing severity as concentration increased. This study shows that copper could inflict histopathological alterations on T. fuscatus var. radula thereby affecting the health of the organism.