Nile tilapia (Oreochromis niloticus) is among the most widely cultured fish species globally, valued for its good growth, palatability, high demand, and adaptability to diverse environmental conditions. In Uganda, Nile tilapia dominates the aquaculture sector and ranks as the second most important commercial species after Nile perch (Lates niloticus) from capture fisheries. Tilapia farming plays a crucial role in reducing unemployment, food insecurity, and improving nutrition for Uganda’s rapidly growing population. Despite its economic potential, tilapia farming faces one of the major challenges of most farmers’ inability to access good-quality seed, often characterized by poor growth performance. Nile tilapia is naturally distributed across Uganda’s water bodies, forming three genetically distinct populations: Albert, Edward-George, and Victoria. However, the reproductive performance of these populations under standardized environmental conditions remains poorly understood. This study aims to fill that gap by providing baseline information on the reproductive traits of these three Nile tilapia populations, offering insights essential for improving the quality of the seed through selective breeding programs.
Methods: Thirty hapas (1 m × 2 m × 1 m) were installed in a pond, with each Tilapia population (Albert, Edward-George, and Victoria) of ten families each, randomly allotted to 10 hapas. Each hapa was stocked with a pair of mature broodstock. After 14 days, hapas were checked for swim-up fry, and the broodstock were returned to holding tanks. Fry were fed with a 42% crude protein powdered feed, three times daily. After three months, juveniles were PIT-tagged and stocked into a pond at 4 fish/m³ for another three months. A sample from each population was then anesthetized and examined for reproductive status.
Results
Under standardized conditions, Nile tilapia from the Albert and Edward female populations exhibited higher gonadosomatic index (GSI) values than those from the Victoria, indicating greater reproductive investment and suggesting superior reproductive potential for selective breeding programs (Fig.1). However, no significant differences were noticed among males (p>0.05).
Discussion: The higher GSI observed in Albert and Edward females suggests enhanced reproductive capacity, highlighting this population’s potential suitability for broodstock improvement in Nile tilapia aquaculture.
Conclusion: The superior reproductive performance of the Albert and Edward female populations supports their recommendation for selective breeding programs aimed at enhancing seed quality and productivity in Uganda’s tilapia aquaculture sector.
Keywords: Nile tilapia, Reproductive performance, Gonadosomatic index, Selective breeding, Aquaculture productivity