Comparison of spawning rate between wild and Improved strain of oreochromis shiranus (Boulenger, 1897)

Abstract

The study was conducted to determine the spawning rate of Malawian Tilapia, Oreochromis shiranus bred in hapas and placed in ponds at the Malawi’s National Aquaculture Centre (NAC). Two strains compared were improved strain from fifth (F5) generation brooders which were procured from a selective breeding program and the wild strain. The brood stock fish were grouped into 3 size categories (24-59g which was designated as treatment 1), 60-99g brooders were denoted as treatment 2 and treatment 3 comprised of brooders that were >100g. Two reproductive parameters were measured every fortnight: number of eggs produced and condition factor (CF) of the fish. The results showed no significant differences in the number of eggs produced between improved and wild strain (P<0.05). The study has demonstrated the significance of using body weight and standard length in selecting both wild and improved strain as a selection criterion for brooders in Malawian Tilapia aquaculture industry