Effect of Waterborne Zinc on Survival, Growth, and Feed Intake of Indian Major Carp, Cirrhinus mrigala (Hamilton)

The effect of waterborne zinc on survival, growth, and feed intake of Indian major carp, Cirrhinus mrigala (Hamilton), advanced fry was studied under laboratory condition. Survival rates of C. mrigala advanced fry (2.71+/-0.49 g) after 30 days exposure to control (0.01), 0.03, 0.06, 0.10, and 0.15 mg/L zinc using the static renewal method in freshwater at pH 7.3+/-0.2, temperature 26+/-2 degrees C, and total hardness 114+/-16 mg/L as CaCO3 were 100%. Growth of the fish exposed to 0.10 and 0.15 mg/L of zinc was significantly lower (P<0.05) than in control (0.01), 0.03, and 0.06 mg/L of zinc after 30 days of exposure. However, there were no significant differences (P>0.05) in fish growth between 0.03 and 0.06 mg/L zinc concentrations. Feed intake rates were significantly (P<0.05) reduced in the fish exposed to 0.10 mg/L and higher levels of zinc. The zinc accumulation in the whole body of the fish increased with increasing concentrations of the metal.