Effects of Chromolaena odorata leaf extract on behaviour and haematology of Clarias gariepinus juveniles (Burchell, 1822)

Abstract

The current study investigated the effect of Chromolaena odorata leaf extract on the behaviour and haematology of Clarias gariepinus juveniles. One hundred and fifty (150) juveniles of C. gariepinus (46.02 ± 1.20 g) were exposed to a range of concentrations of C. odorata leaf extract: 10 mg l⁻¹, 20 mg l⁻¹, 30 mg l⁻¹ and 40 mg l⁻¹ at 24 h, 48 h, 72 h and 96 h exposure duration. Dose- and time-dependent behavioural changes, such as loss of equilibrium, hyperactivity and jerky movement, were observed in fish exposed to C. odorata leaf extract. There was a progressive and dose-dependent decrease in response to stimulus with time, until a state of calmness, which was subsequently followed by death. Haematological analyses revealed significant and dose-dependent decreases in pack cell volume, haemoglobin and erythrocytes, and elevated white blood cells, in exposed fish relative to control fish.