population itself before any selective breeding,was reported to have a 60% advantage in harvest weight over widely farmed Philippinestrains (footnote 27). This could be mostly attributed to the crossbreeding of strains during development of the synthetic base population. Together with the subsequent responses to selection, this represents a claimed growth performance advantage of about l25% for GIFT over Philippine farmed strains. In other words, in comparable environments, GIFT should reach harvest size in less than half the time taken by unimproved tilapia strains.