The effect of copper and zinc at neutral and acidic pH on the blood coagulation of Oreochromis mossambicus

Abstract

The effect of copper and zinc on fish blood coagulation under alkaline and acidic conditions and the possible occurrence of disseminated intravascular clotting under these conditions have been poorly studied to date.

It was found that the blood coagulation system of adult O. mossambicus exposed to copper and zinc at neutral and acid pH levels was altered. Deviations from normal coagulation times are either inherent or are due to factors such as liver damage, vascular abnormalities, and mineral and vitamin deficiencies. Exposure to copper and zinc at neutral pH caused prolonged blood coagulation, whilst at acidic pH exposure to these metals caused accelerated coagulation. Haemostatic conditions induced by these metals were fibrinolysis, haemophilia, thrombocytosis (hypercoagulability) and thrombocytopaenia.


Keywords: copper; zinc; neutral pH; acidic pH; blood coagulation; Oreochromis mossambicus; Olifants River; South Africa


(Afr J Aqua Sci: 2002 27(1): 47-60)