CHANGES IN ELECTROLYTES LEVEL OF CLARIAS GARIEPINUS (BURCHELL 1822) EXPOSED TO SUBLETHAL CONCENTRATIONS OF OILFIELD WASTEWATER

*N. P. Akani and C. E. I. Nwankwo

ABSTRACT

The electrolytic changes of twenty-eight adult Clarias gariepinus (Burchell, 1822), (mean weight 205 ± 12.89g SD; Mean length; 31.13 ± 3.82cm SD) exposed to sub-lethal concentrations (0, 10, 20, 30, 40, 50 and 60%) of an oilfield wastewater over a period of twenty eight (28) days were studied in a semi-static system. At the end of 28 days, tissue/organ and plasma samples were collected for electrolysis using standard methods. Insignificant (p≤0.05) fluctuations in electrolytes (sodium, potassium, chloride, calcium and bicarbonates ions) were observed in exposed fishes when compared to the control group. These fluctuations in electrolytes suggest the effort made by the fish to combat the stress imposed by the toxicant. The ions (electrolytes) are involved in regulation of osmotic changes in the fish and can be used to measure long term effect of C. gariepinus exposed to oilfield wastewater. The proper treatment of oilfield wastewater prior to discharge into the recipient water body is advocated to reduce ecotoxicological problems.

Keywords: Clarias gariepinus, ecotoxicology, electrolytes, oilfield wastewater, organ, tissue.