Effect of crude oil on some hematological parameters of the freshwater fishes, oreochromis niloticus

الملخص EN

In the present study collected fishes (Oreochromis Nilotic us) were exposed to different concentrations (100, 250, 500, 1000, 1500, 2000 ppm) of crude oil extract for a varying period (for up to 48 h in lethal extract and 72 h in sub lethal one).

A number of hematological changes in the hemoglobin level, the hematocrit value and the blood sugar level were studies.

All the parameters have been increased except the hemoglobin level which fell down significantly in an acute lethal concentration (2000 ppm) after 48 h of exposure.

The hematocrit value increased significantly in 2000 ppm.

The blood sugar level showed hyperglycemia in all concentrations.

The increase in ascorbic acid was pronounced in higher concentrations. Changes occurring in different parameters seemed to be reversible as well as all the parameters returned to their normal levels after returning the fish to normal water media, except the nuclear swelling which did not resume the normal functioning even after a prolonged treatment (more than one month) in the recovery jar.

The hematological effects induced by crude oil resembled partly those exposed to severe hypoxic conditions and partly to the fish poisoned by heavy metals (copper and zinc).

On the basis of results obtained in these investigations, crude oil may be categorized as a complex toxic agent.