TOXICITY IMPACT OF DIETHYL PHTHALATE ON SOME LABORATORY POPULATION OF JUVENILE CLARIAS GARIEPINUS (BURCHELL, 1822)

Abstract Diethyl phthalate is a kind of plasticizer widely used in industries and have recently attracted special attention of the scientific community, regulatory agencies and the general public as a consequence of their high production volume, widespread use and possible endocrine related effects. Hence the present study was conducted to assess the toxicity impact of diethyl phthalate (DEP) on the the laboratory population of Clarias gariepinus. The fish was treated with different lethal concentrations (25.0, 37.5, 50.0, 62.5, 75.0 and 87.5 µL/L) of DEP and sub lethal concentrations (26.0, 34.5, 43.25, 53.8 and 62.5 µL/L). The 96h LC50 value of DEP-exposed C. gariepinus was estimated by probit analysis method (with 95% confidence limits) and the survivability of the test organisms was assessed and recorded. Hematological parameters such as red blood cell count (RBC), white blood corpuscles (WBC), hemoglobin (Hb), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean cell volume (MCV), were observed in the exposed fish and compared with the control group. Histological alternations in the gills, liver, kidneys and brain of the test organisms were equally analyzed. The test organisms showed some behavioural abnormalities to the toxicant. The results also revealed some degree of histological degradation in the analyzed organs. All these responses were DEP concentration-dependent. The present findings revealed that Diethyl phthalate exerts its toxic action even at sub lethal concentrations and hematological parameters, histological degradation and abnormal behavior may be sensitive indicators to evaluate phthalate intoxication. Therefore, caution should be taken in the usage of such chemical by the concerned industries and also, the usage must be strictly monitored.