Acute Toxicity Assessment of Ethanolic Extract of Unripe Plantain (Musa paradisiaca) Peel on Juveniles of Clarias gariepinus (Burchell, 1822): Implications for Its Use as a Feed Additive in Aquaculture Diets

Abstract

The increasing search for cost-effective and sustainable feed additives in aquaculture has stimulated interest in the utilisation of agricultural wastes such as unripe plantain (Musa paradisiaca) peels. This study evaluated the acute toxicity of ethanolic extract of unripe plantain peels on juveniles of Clarias gariepinus to determine its safety for potential application in aquaculture feed formulation. Ten juveniles were stocked in each plastic aquarium containing two litres of water and exposed to 0, 20, 25, 30 and 35 mg/L of the extract in duplicate batches (A and B) under static bioassay conditions for 96 hours. Mortality, behavioural responses, water-quality parameters and histopathological alterations of the gills and liver were assessed following standard procedures. No mortality was recorded in the control and 20 mg/L treatments, while 10% mortality was observed at 25 mg/L. Mortality increased to 20-30% and 40-50% at 30 and 35 mg/L, respectively. Behavioural abnormalities, including air gulping, erratic swimming, respiratory distress and vertical erection, increased with concentration and exposure duration. Significant variations (p < 0.05) were observed in pH, dissolved oxygen, conductivity and temperature across treatments and exposure periods. Histological examination of the gills revealed no pathological alterations in any treatment group, indicating preservation of gill structural integrity. Similarly, liver tissues from the control and 25 mg/L groups showed normal architecture, whereas moderate to severe hepatic distortions, characterised by tissue degeneration and structural disorganisation, were observed at 20, 30 and 35 mg/L. The findings indicate that lower concentrations of ethanolic extract of unripe plantain peels are relatively safe for C. gariepinus juveniles, while higher concentrations may induce toxicological effects. Therefore, careful dosage consideration is necessary before incorporation into aquaculture feed formulations.