Effect of Environmental Acidic pH on Oxygen Consumption of Fish, Cyprinus carpio (L.)

The present study was aimed to investigate the total oxygen consumption of freshwater fish Cyprinus carpio during exposure and acclimation to sublethal acidic pH (5.0) medium. The oxygen consumption of fish significantly depleted in all the days of exposure to sublethal acidic pH 5.0 starting from first day to fourteen days of exposure. The rate of total oxygen consumption depletion was higher on first day. From the second day onwards a gradual decreasing trend was observed in the depletion up to 14th day of exposure. The unit oxygen consumption of fish on exposure to sub-lethal pH medium exhibited significant depletion when compared to control. The rate of depletion was maximum in the initial days of exposure and was reduced gradually in twelfth and fourteenth day of exposure. But, at day 14th not significant decrease was observed in both the parameters of the experimentation. This observation indicates that the fish was capable of regulating their metabolic modulations and physiological functions through acclimation process to be the possible reason for the successful survival of fish in acidifying water. The reduced oxygen consumption of fish on exposure to sublethal acidic medium confirms the prevalence of hypoxic condition in the surrounding medium.