Growth performance of major carps during exposure of zinc and bioaccumulation in fish body organs

Growth is an index of metals influence on a fish. This investigation aimed to determine growth responses of major carps viz. Catla catla, Labeo rohita and Cirrhina mrigala during exposure to sublethal concentration to zinc. The variations among fish age, species, treatment (zinc) of growth parameters viz. weight increment, fork lengths, and condition factor were statistically significant at P<0.01. The control fish age group 90,120,150 and 180 day showed better feed conversion ratio 0.234, 0.168, 0.132 and 0.29 as compared to that of zinc exposed fish which showed range 0.01 to 0.23. Three fish species showed significantly higher amount of zinc in liver than other organs. Labeo rohita showed significantly higher trend for zinc accumulation in body organs than as compared to Cirrhina mrigala and Catla catla. Among body organs; skin, muscle, scales displayed significantly lesser trend for zinc accumulation. It is concluded that metal intoxication significantly reduced the growth of all three fish species and may also show good indicator of metals present in surrounding environment.