Masculinization of genetic female Nile tilapia (Oreochromis niloticus) by dietary administration of an aromatase inhibitor during sexual differentiation
✍ Scribed by Kwon, Joon Yeong ;Haghpanah, Vahid ;Kogson-Hurtado, Luz Mary ;McAndrew, Brendan J. ;Penman, David J.
- Book ID
- 101324533
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 116 KB
- Volume
- 287
- Category
- Article
- ISSN
- 0022-104X
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✦ Synopsis
A series of experiments was carried out in which genetically female Nile tilapia (Oreochromis niloticus) fry were treated with Fadrozole, a nonsteroidal aromatase inhibitor (AI), in the diet during the period of sexual differentiation. Batches of tilapia fry treated with AI during the first 30 days following yolk-sac resorption (7-37 days post hatch, dph) showed a dose-dependent increase in the percentage of males from 0 to 200 mg • kg -1 . The percentage of males remained approximately constant (92.5-96.0%) from 200 to 500 mg • kg -1 . Any continuous 2-or 3-week treatment with 500 mg • kg -1 AI in this 4-week period successfully masculinized the majority of the treated fish (>80%). Treatments of 1 week duration revealed that the most sensitive time to AI lies in the first week (between 7 and 14 dph). Progeny testing of males from AI-treated groups gave results indicating that these were XX males, as expected. These experiments strongly implicate aromatase activity as a key factor in sexual differentiation in the Nile tilapia.