Shading of Ponds Improves the Reproductive Performance of Female Nile Tilapia (Oreochromis niloticus L.) Breeders during Warm Months

One of the major challenges facing the tilapia farming industry is the production of sufficient amount of quality seeds during warm months. Extreme temperatures brought about by global warming affects the reproduction of fish. Hence, this study evaluated aquashade technology as a possible solution to the problem on low seed production during warm months. The effectiveness of black greenhouse nets with different shading capacities of (i.e. 40% and 80%), as top cover of breeding ponds was investigated on the reproductive performance of female Nile tilapia breeder. Results of the study showed that shading of ponds reduced the average water temperature by 1 - 2 °C at 0700 h and 3-6 °C at 1100 h to 1500 h. The lower water temperature on shaded pond improved the gonadal development and maturation on female breeders, thus promoting better gonadosomatic index value and pattern. No significant differences were recorded on the spawning rate and seed production per female among the shaded treatments, with 40% shading capacity treatment having the numerically higher value. The application of aquashade can eliminate the deleterious effect of extreme water temperature on the reproduction of breeders and is therefore effective in improving the reproductive performance of female Nile tilapia during warm months.