STUDIES ON GROWTH PERFORMANCE OF METALS MIXTURE STRESSED CIRRHINA MRIGALA IN EARTHEN PONDS

The whole experiment was conducted in two phases. During phase-I fingerlings of Cirrhina mrigala were divided into two groups, one group was exposed to sub-lethal concentration of metals mixture (Fe, Zn, Pb, Ni, Mn) while other was kept un-stressed as control in glass aquaria for 30 days. During stress period fish (unstressed) showed significantly better growth, fork and total lengths as 2.24g, 6.11 and 6.95mm, respectively. At the end of phase-I, both stressed and control fish were shifted to earthen ponds for phase II study the growth parameters in semiintensive culture for a period of six months. The ponds were fertilized with poultry droppings at the rate of 0.16g nitrogen per 100g net fish weight daily. During each trial, fish was fed daily at the rate of 2% body weight (6 days a week) with the feed of digestible energy equal to 2.90 Kcal.g^-1 and 35% digestible protein. Analysis of variance revealed that only months had statistically significant effect on growth performance of Cirrhina mrigala in terms of weight, fork and total length increments. While treatments and interaction of months x treatments had nonsignificant results. On the basis of this study, it was concluded that under sub-lethal stress of metals mixture to Cirrhina mrigala in the glass aquaria showed significantly lower growth in terms of wet weight increment as compared to control fish. However, during semi-intensive culture system in pond, fish Cirrhina mrigala showed non-significantly better growth performance in the wet weight, fork and total lengths increments in unstressed pond as compared to treated ponds.