Morphological, haematological and biochemical changes in African catfish Clarias gariepinus (Burchell 1822) juveniles exposed to clotrimazole

Abstract

Clotrimazole (CLO) is an imidazole fungicide used in human and veterinary medicine for treating fungal infection. This study evaluated the changes in morphological, haematological and biochemical indices in Clarias gariepinus juveniles exposed to CLO. After the acute exposure, the 96 h LC50 value of CLO determined by probit analysis was 38.79 mgl−1. Based on this value, fish were exposed to sublethal concentrations of 7.76, 3.89, 1.94 and 0.00 mgl−1 (control) of CLO for 21 days and were allowed to recover for 7 days. The result revealed no significant effect on the hepatosomatic index and condition factor of the exposed fish. There were concentration and time-dependent significant decreases in red blood cell (RBC), haemoglobin (Hb), packed cell volume (PCV) and mean corpuscular volume (MCV) with significant increase in the white blood cell (WBC), mean corpuscular haemoglobin concentration (MCHC), and mean corpuscular haemoglobin (MCH) in the exposed group when compared with the control. A mixed trend was observed in the levels of neutrophils, lymphocytes, monocytes and eosinophils. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and glucose values significantly increased, while protein levels were reduced (p < 0.05) throughout the 21-day exposure and the 7-day recovery period. The present research indicated that CLO may have potential toxic effect on non-target organisms especially fish and, therefore, should be monitored in the aquatic ecosystem.