Lethal Toxicity of Aqueous Extract of Sodom Apple (Calotropis procera) on African Catfish (Clarias gariepinus) (Burchell, 1822) Juveniles

Abstract

The experiment was performed to check the lethal toxicity of aqueous extract of Calotropis procera on Clarias gariepinus juveniles. A range finding test was done and the concentrations for the definitive tests were determined. A total of 150 African catfish juveniles of average weight 9.37±0.08g were randomly selected and distributed into four treatments in triplicates of 20mg/L, 40mg/l, 60mg/L, 80mg/L concentrations and a control (0.00) using a static bioassay test over a period of 96 hours. Behavioral responses observed during exposure of the fish to lethal concentrations included erratic swimming, air gulping, haemorrhage, loss of equilibrium and sudden death. All data obtained were summarised using descriptive statistics for the mortality, water quality parameters, growth performance and nutrient utilization. While one-way analysis of variance (ANOVA) was used to assess differences in means among the concentrations and Duncan multiple range tests was used to separate the means, where there was a difference. Physico-chemical water parameters and haematological parameters showed various significant difference among the treatments (P< 0.05). C. procera at higher concentrations of 40mg/L and above was highly toxic to fish, which led to erratic behavior and mortality.