Catalase Activity in Response to Metals in Freshwater Fish Catla catla

Catalase activity in response to binary metal mixture of Zn + Ni was studied in gills, hepatic, renal and cardiac tissues of Catla catla. A total of 30 fish fingerlings were kept in two glass aquaria (15 in controlled condition and 15 in metal mixture containing aquarium) for the period of two weeks. After the completion of the trial period, fish were dissected for different organ collection. The extracted organs were homogenized in phosphate buffer (50 mM; pH 7.0). The activity of catalase was determined by absorption at 240 nm by using the standard methods. The inferences showed higher catalase activity in liver (223.33 ±1 UmL-1), kidney (163.33 ± 0.7 UmL-1), gills (123.33 ±0.9 UmL-1) and cardiac (120 ±3 UmL-1) tissues of Zn + Ni treated fish in comparison to controlled fish liver (116.66 ±2 UmL-1), kidney (101.66 ±1 UmL-1), gills (96.66 ±0.66 UmL-1) and cardiac tissues (70 ±0.33 UmL-1) in this study. Statistically, significant differences at p ≤ 0.05 was observed for catalase activity between Zn + Ni stressed and control fish groups. While, in different organs of both group of fishes the catalase activity order was observed as hepatic > renal > gills > heart. Findings of this study would be helpful in monitoring aquatic ecosystems using fish antioxidant system which acts as a bio-indicator of metal contamination.