Abstract

Tilapia (Oreochromis sp.) is one of the main species in aquaculture today due to its nutritional characteristics and high tolerance to different culture media. However, commercial tilapia production generally requires the use of monosex populations with male individuals. One way to obtain this kind of fish stock is through the use of hormones, after which during the production cycle, the reproductive stage is nullified in the whole herd. This aim is achieved by means of fish sexual reversion to males with controlled techniques immediately as fish are old enough to be eaten. In this work, a technique for Tilapia sexual reversion by food aspersion using 17α-methyltestosterone is presented. To avoid competition, the experiment was done in five tanks of 100 L with each containing 500 animals. The result shows an efficiency of male reversion above 97% of the total fry produced in a group of 2500 eggs hatched.

Key words: Fingerling, male fish, productivity, fast growth, hormone.