Effects of varying concentrations of ethanol leaf extract of Paullinia pinnata on histopathology of Clarias gariepinus juveniles

The study investigated of varied levels’ effects of Paullina pinnata ethanol leaf extract on Clarias gariepinus juveniles in a 2-phase (range-finding and main) experiment. Two hundred and fifty Clarias gariepinus juveniles were acclimatised for two weeks at the Fish Hatchery complex of the Federal University of Agriculture, Abeokuta, where they were weighed with a mean weight of 9.00 ± 1.00 g, distributed into 12 plastic tanks of 35 L capacity, and arranged in a completely randomised system with a stocking density of 9 fish per tank. For the first phase (i.e., range-finding) experiment, 99 C. gariepinus juveniles were stocked into the plastic tanks (35 liters) filled to 10 litres of the volume, dosed with 5 mL syringe drops of 500, 1000, and 1500 mg L-1 extracts in triplicate, where no behavioural changes and mortality were observed. For the main experiment, 108 C. gariepinus juveniles were stocked and dosed with increased 5 mL syringe drops of 0, 3000, 5000, and 7000 mg L-1 extracts in triplicated. Analysis of variance (ANOVA) analysed the data, and the Duncan Multiple Range Test separated the means. The histological results of the main experiment revealed severe lesions on the gills of the varied-extract exposed fish. The extract had a significantly negative effect on the exposed fish and posed a threat, which eventually led to death at a higher concentration. The study concluded and recommended that the range-finding concentrations of the extract should always be administered by the fish farmers while exploring the ethanol leaf extract of Paullinia pinnata to lessen the threat to life below water.