Efficacy of Tannin Extract from Cape Gooseberry Root Physalis peruviana L. as Egg De-Adhesion Agent during Artificial Propagation of African Catfish Clarias gariepinus Burchell

Abstract

The study assessed the best immersion period and concentrations of the Cape gooseberry root Physalis peruviana that can efficiently remove egg adhesiveness of Clarias gariepinus. One male and one female C. gariepinus brood stock weighing 1.0 kg and 1.3 kg respectively, were used for the experiment. Three different concentrations (0.5%, 1%, and 2%) of tannin extract from Cape gooseberry root were used. Tannic acid (0.75g) diluted in 1 litre of water was used as reference de-adhesion agent, while water was used as control. The fish eggs were rinsed with the solutions at different durations of 0.5, 1 and 2 minutes. Each concentration and rinsing time was recorded in triplicates. Data generated were subjected to Univariate Analysis of Variance Test, and third order Polynomial regression analysis was then used to determine the best concentration and immersion period that neutralizes adhesiveness in eggs of C. gariepinus. Results of the study showed that there were no significant differences (p≤0.05) in the non-adhesive eggs and hatching of eggs immersed in tannin extract from Cape gooseberry root and Tannic acid solution but significantly different from the control. Therefore, this study showed that tannin extract from Cape gooseberry root at 1% concentration and 1 minute immersion period is more efficient for egg adhesion and increase hatching in C. gariepinus.