The significantly better culture performance of the 95%male population (total yield and FCR) is in agreementwith previous results of higher yields (Mair et al., 1995) and better FCRs (Toguyeni et al., 1997; Chakraborty et al., 2011) for male tilapia populations compared to mixed-sex populations. Previous studies have also reported a lack of significant differences in survival between mixed-sex and male tilapia populations (Chakraborty et al., 2011; Dan and Little, 2000).