Effects Of Acute And Sub-Lethal Concentrations Of Phostoxin On Weight Changes And Haematology Parameters Of <i>Clarias Gariepinus</i>

Abstract

Fish are sensitive to a wide variety of chemicals and toxic conditions. In aquatic environment, organophosphate may cause several physiological and biochemical defects in fishes. Clarias gariepinus (mean weight 10±0.1g) was exposed to acute and sub-lethal concentrations of phostoxin to evaluate the toxicity of phostoxin organophosphate. Effect of phostoxin on haematological parameters and weight changes of juvenile Clarias gariepinus was also investigated. The concentrations used during the acute toxicity test were 1.00, 2.0, 4.00, 6.00 mg/l with a control of 0.00mg/l; while the concentrations of the toxicant used during the 28-days sub-lethal exposure were 0.60, 0.40, 0.20 mg/l with a control of 0.00 mg/l. The lethal concentration (LC50) value of phostoxin was 2.20mg/l for 96h of exposure. The results obtained from the sub-lethal exposure showed that there was a progressive decrease in weight gain of fish as the concentration of the toxicant increased. Also, haematological indices indicated that the fish became hyperglycaemic and hypoproteinaemic and the severity of this condition were directly proportional to the phostoxin concentration. C. gariepinus is susceptible to phostoxin; therefore use of phostoxin in disinfection on/near fish farm or area close to aquatic environment should be discouraged. Keywords : Clarias gariepinus , phostoxin, Toxicity test, Weight, Haematology Journal of Environmental Extension Vol. 7 2008: pp. 72-77