EFFECTS OF ZINC TOXICITY ON BIOCHEMICAL-COMPOSITION OF MUSCLE AND LIVER OF MURREL (CHANNA-PUNCTATUS)

Selected specimens of murrel (Channa punctatus) were exposed to a subl ethal zinc concentration (2.4 mg L-1), determined as a fraction of the 96-h LC50 value, for 15, 30, 60, and 120 d. The zinc exposure produce d marked changes in the chemical composition of liver and muscle tissu es. These changes were more severe after 60 and 120 d, suggesting a cu mulative action of zinc on the tissues. The metabolism of the fish dec reased with the time of exposure and there was a decline in the calori fic value of lipid, protein, and glycogen in muscle and liver. Glycoge n and iron were the components most affected and the nutritive value o f the fish was also adversely affected. (C) 1998 Elsevier Science Ltd.