Department of Zoology, University of the Punjab, Lahore 54590, Pakistan
A. S. Chaudhry School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
We examined the muscles from replicated samples of Cirrhinus mrigala as a bio-indicator of water pollution following sewage and industrial discharges from the Lahore city into Ravi River of Pakistan. For this, C. mrigala was netted from three variably polluted downstream sites (B, C and D) and one less polluted upstream site (A). The fish was sampled during low (winter) and high (post monsoon) river flow seasons. The fish muscles from site D showed 28 % less total carbohydrates than the fish caught from site A. The muscle carbohydrate contents were further decreased at sites B and C by 58 and 59 % and 77 and 74 %, during low and high flows, respectively. Moreover, total lipids, cholesterol and RNA contents for the muscle of the fish from the downstream locations were also decreased up to 29, 68 and 58 %, respectively. Conversely, total protein, soluble protein and DNA contents were increased in fish muscles progressively downstream during both the low- and high-flow seasons. It appeared that the fish muscle components can change with the level of water pollution which may affect the fish attributes as a safe food.