Growth and Bioaccumulation of Iron in the Body Organs of Catla catla, Labeo rohita and Cirrhina mrigala during Chronic Exposures

Laboratory tests were conducted, with nine age groups of three fish species, to determine their feed intake, weight gains and feed conversion efficiency (FCE) during 60-days exposure to sub-lethal (1/3 of LC50) iron (Fe) concentrations of 40.05, 23.33 and 40.08 mg L-1 for Catla catla, Labeo rohita and Cirrhina mrigala, respectively. This investigation also focuses on the extent of Fe bioaccumulations in the fish organs viz. gills, kidney, liver, skin, muscle and scales during chronic toxicity exposure growth trials. Both treated and control three fish species showed significantly variable responses towards feed intakes, weight increments and FCE values. Feed intake in Fe exposed fish species did not cause significant increase in their body weights. However, control fish exhibited significantly higher feed intake, weight increments and FCE than that of treated fish. Sensitivity of fish to Fe toxicity decreased significantly with age. Significant differences existed among nine fish age groups for the accumulation of Fe in the body organs of three treated fish species. Fish liver and kidney showed significantly higher tendency for the accumulation of Fe. L. rohita showed significantly higher tendency for the accumulation of Fe in its body than C. catla and C. mrigala. Fe contents in gills, kidney and skin increased with fish age also. However, Fe accumulation was predominantly highest in the kidney, followed by that in liver and gills. The accumulation of Fe in fish kidney had significantly direct relationships with both temperature and pH of water. However, water hardness had significantly inverse relationship with the uptake and accumulation of Fe by the fish kidney. © 2010 Friends Science Publishers