In the present research, laboratory studies were conducted with nine life stages of three fish species viz. Catla catla, Labeo rohita and Cirrhina mrigala to determine their feed intake, weight gains and feed conversion ratios under sub-lethal chronic exposure of zinc toxicity. Zinc bioaccumulations in fish organs viz., gills, kidney, liver, skin, muscle and scales during chronic toxicity exposures, have also been determined. All the three fish species showed uniformity in their response towards feed intake, weight increment and feed conversion ratios under sub-lethal zinc chronic exposures. Feed intake by all the three fish species increased significantly with metal exposure time. However, this significant increase in feed intake did not result in fish weight escalation and hence resulted in low feed conversion ratios. Sensitivity of the fish to zinc decreased with fish age also. Different fish age groups showed statistical differences for the accumulation of zinc in their bodies. However, the patterns of these accumulations varied significantly among fish organs. Fish liver and kidney exhibited significantly higher tendency for the accumulation of metals.