EFFECT OF COPPER ON BLOOD-COAGULATION OF OREOCHROMIS-MOSSAMBICUS (CICHLIDAE)

The effect of copper on the blood coagulation in freshwater fish, Oreo chromis mossambicus was investigated, These fish were exposed to suble thal copper concentrations over short-term (96 hr) and long-term (4 wk ) periods, at 29 +/- 1 degrees C (summer) and 19 +/- 1 degrees C (wint er), in experimental flow-through systems, Copper concentrations appli ed during short-term exposures were 0.16 mg/l and 0.40 mg/l, respectiv ely, while 0.40 mg/l copper was applied during the long-term exposures . After a photocymographic observation of blood, during all the phases of coagulation was made, it was evident that there were delays in the blood coagulation times, as well as decreases in the shear modulus (e lasticity) of the clots formed, after the exposure of the fish to copp er concentrations at both temperatures. Copper was found to induce hae mophila at 29 +/- 1 degrees C and 19 +/- 1 degrees C, while at the lat ter it also induced thrombocytopenia. Thus exposure to copper lead to coagulation defects, which caused haemorrhage in the body tissue, whic h cam eventually cause the death of those fish.