Aims: To examine the dietary effects of Prunus amygdalus dulcis seed meal on the sperm quality of male African Catfish (Clarias gariepinus).
 Place and Duration of Study: The experiment was carried out at the Department of Fisheries and Aquaculture Technology Teaching and Research Farm, The Federal University of Technology, Akure for a period of 70 days.
 Methodology: Five diets with crude protein of 40% were formulated with different inclusion levels of P. amygdalus dulcis seed powder. D1 (control) has 0 g of the powder, while D2, D3, D4 and D5 has 5, 10, 15 and 20 g of the P. amygdalus dulcis seed powder in 100 g of feed respectively. A total of 45 C. gariepinus were randomly distributed into 15 concrete tanks (2×2×1.5 m) at stocking density of 3 fish per tank and constant water level of 1 m was maintained in the experimental tanks. The fish were fed at 3% of body weight twice a day between 08.00-09.00 and 16.00-17.00 hours for a period of 70 days. At the end of the 70-day experiment, gonadosomatic index and reproductive indices such as milt volume, motility duration, spermatozoa count, percentage motility, percentage fertilization, percentage hatchability and percentage survival of fry were determined. The qualities of the milt were assessed by aid of microscope and by fertility tests. Histological examination of the testes of fish fed each of the diets was also carried out.
 Results: Fish fed experimental diets showed significantly improved gonado-somatic index and reproductive indices over the control treatment. Higher gonado-somatic index and reproductive indices were recorded for the fish fed diet of 20 g/kg P. amygdalus dulcis seed powder compared to other experimental diets.
 Conclusion: The results indicated that supplementing diets with P. amygdalus dulcis seed powder enhanced growth and improved gonadosomatic index, and reproductive indices of male C. gariepinus broodstocks which can be exploited in fish seeds production.