Ammonia toxicity: metabolic disorder in nine freshwater teleosts.

An inverse relationship was recorded between the concentration of ammonium chloride (5, 10, 15, and 20 ppm) and the fall in pH and dissolved oxygen of water; with ammoniacal nitrogen and carbon dioxide the relationship was reversed. The effect of various concentrations of ammonium chloride (5, 10, 15, and 20 ppm) on tissue glycogen, serum glucose and lactate level was studied in 9 freshwater teleosts from a tropical environment. The fall in tissue (liver, muscle, and brain) glycogen was inversely proportional to ammonia concentration. An elevation in renal glycogen was recorded up to 10 ppm with a decrease thereafter. The greatest fall in tissue glycogen was recorded in the liver (C. mrigala), muscle, brain (C. catla), and kidney (C. mrigala). There was a direct relationship between ammonia concentration and accumulation of glucose and lactate in serum. The decrease in tissue glycogen was greater in major carp species than in murrels or catfish.