Heavy metals toxicity and bioaccumulation patterns in the body organs of four fresh water fish species

Various environmental pollutants, including metals can cause toxicological effects on aquatic animals especially fish species. Laboratory experiments were conducted to determine acute toxicity and bioaccumulation patterns of arsenic (As), nickel (Ni) and zinc (Zn) in 150-day old fish species (Labeo rohita, Cirrhina mrigala, Catla catla and Ctenopharyngodon idella), separately, in glass aquaria under constant water temperature (30oC), total hardness (300 mg L-1) and pH (7.5). Catla catla showed significantly (P<0.05) highest sensitivity to metals while L. rohita was least sensitive. Significantly variable accumulation of metals was observed in fish that followed the order: Zn>Ni>As. Among exposed fish species, Cirrhina mrigala exhibited significantly higher ability to amass Ni (146.8±149.1 μg g-1) and Zn (243.0±190.5 μg g-1), followed by Ctenopharyngodon idella, Labeo rohita and Catla catla at 96-h LC50. Liver showed higher tendency to accumulate Ni, followed by gills and kidney with significant differences while kidney showed higher tendency to accumulate As, followed by liver. Fins and scales exhibited significantly (P