Tilapia Sex Reversal, the technology for producing all-male tilapia, has revolutionized the fanning of the fish world wide.
The technology which is regarded as a milestone in global aquaculture is widely applied in the Philippines and other countries like Israel, Thailand, and the United States. More than 50 percent of the Nile tilapia produced in ponds and cages in the Philippines have been sex-reversed.
The technology is based on the theory that the development of the sex organ (testis for male and ovary for female) in the fish can be artificially influenced by feeding of a synthetic sex hormone (methyltestosterone for male and estrone for female) during the “sexless period” of the young. Hormonal or induced sex reversal was first demonstrated in the 1950s by T. K-O. Yamamoto of Japan in the medaka, an aquarium fish.