EFFECT OF TURRAEA HETEROPHYLLA EXTRACT SMITH, 1819 ON MASCULINIZATION IN TILAPIA OREOCHROMIS NILOTICUS (LINNE, 1758) REARED IN A CONTROLLED ENVIRONMENT IN IVORY COAST

In order to propose an alternative to the use of the hormone 17-α-methyltestosterone for sex reversal in Nile tilapia (Oreochromis niloticus), a masculinization study was conducted in a controlled environment using an extract of the plant Turraea heterophylla at the Nangui ABROGOUA University fish farm in 2024. Two diets were prepared using a commercial feed (ALIMPOI) containing a dose of Turraea heterophylla (30 g/kg) and 17-α-methyltestosterone (70 mg), compared to a control diet. Larvae with an average initial weight of 15 ± 0.01 mg were fed these diets in aquariums at a density of 50 larvae per aquarium for 21 days. The fish were then reared in tanks at a density of 30 fish/m³ (148 fish/tank) and fed their standard diet for 90 days. At the end of the experiment, the average final weights ranged from 46.12 ± 2.59 g to 67.94 ± 2.87 g, depending on the treatment. The best growth and feed conversion ratios were observed in the fish treated with hormones, followed by those treated with Turraea heterophylla. The 17-α-methyltestosterone treatment resulted in a 100% masculinization rate, compared to 86.83% for the Turraea heterophylla extract and 51.41% for the control group. A survival rate of 96.81 % was observed at the end of the rearing period. This study demonstrated that completely replacing 17α-methyltestosterone with plant extracts would significantly reduce the production costs of single-sex fry.