TOLERANCE LIMITS AND DETOXIFICATION MECHANISMS IN THE FISH TILAPIA MOSSAMBICA SUBJECTED TO AMMONIA TOXICITY

Abstract

The effect of induced ammonia toxicity on selected enzyme systems of carbohydrate and nitrogen metabolism of freshwater fish, Tilapia mossambica was studied. An increas-s in lactate dehydrogenase (LI>H) and decrease in succinate (SDH) and malate dehydKjgenase activity levels were noticed in all the tissues studied. The activity levels of asparate aminotransferase (AAT) decreased in all the tissues, while that of alanine aminotransferase (AlAT) had shown an increase. An elevation in the levels of Eirginasts activity and urea was found in the gill and liver tissues. The mettbolic sigmficance of these results is discussed