Evaluation of Lignan as a Natural Hormonal Diluent for Enhancing Reproductive Performance of African Catfish, Clarias Gariepinus

This study evaluated the effectiveness of lignan extracted from watermelon (Citrullus lanatus) seeds as a hormonal diluent during the artificial propagation of C. gariepinus. A completely randomised design consisting of five treatments was employed: 0% (control), 25%, 50%, 75%, and 100% lignan inclusion levels, each replicated three times. Reproductive performance indices, hormone residue levels, and water quality parameters were assessed. Results showed that lignan significantly influenced reproductive performance (P0.05) among treatments, indicating that lignan did not interfere with hormone metabolism or clearance. Water quality parameters remained within acceptable ranges and were not significantly affected by lignan inclusion. Third-order polynomial regression analysis identified approximately 35% lignan inclusion as the optimum concentration for hatchability enhancement, with a strong model fit (R² = 0.9596). The study demonstrates that lignan possesses reproductive-enhancing properties and can effectively function as a hormonal diluent during artificial propagation of C. gariepinus. Therefore, lignan represents a safe, environmentally friendly, and cost-effective alternative for improving hatchery performance and promoting sustainable aquaculture production.