Water samples were collected by inverting a 250 ml sterilized glass bottle 30 cm below the pond water surface. All samples were transferred to the lab in an icebox. Analysis was initiated within 2 h of sample collection. Five fish were sampled at the same time with water sampling by harvesting with a net and put in a sterile polyethylene bag. 10 g of the muscle portion of fish along with the skin was homogenized for 1 min with 90 ml of peptone water in a homogenizer