Effect of environmental acidity and alkalinity on the physiology of Tilapia mossambica during acclimation

The pattern of carbohydrate metabolism in the muscle of the freshwater fish, Tilapia mossambica (Peters) varied according to the pH of the environmental medium. On acclimation to a more acidic water, the white muscle showed an elevated glycogen content with suppressed glycolysis. In contrast, the muscle tissue showed an accelerated glycolytic pathway with the accumulation of metabotic acids on acclimation to a basic water. In an acidic medium phosphorylase activity was inhibited with an elevated LDH activity, while the reverse pattern was observed in an alkaline medium. The oxidative pathway was elevated in both. Acclimation to acidic and basic environmental waters leads to an adaptive compensatory mechanisms providing increased resistance capacity to the fish under pH stress.