Equipe de France Au Kenya, la part sexage est couramment utilisé, mais avec seulement environ 60% de réussite. Clarias est utilisé comme un prédateur dans une installation de contrôle biologique, ce n'est pas très parce que l'un succès mai terminer avec quelques gros poisson-chat qui ne sont pas efficaces dans le contrôle de la prolifération de tilapia. Macharia -----Original Message----- From: sammy Macharia [mailto:sammacharia@yahoo.co.uk] Sent: 20 November 2008 09:18 To: William Leschen Subject: Re: [Sarnissa-stakeholders] Gender control for tilapia production French Team In Kenya, hand sexing is commonly used but with only about 60% success. Clarias is used as a predator in a biological control setup, this is not very success because one may end up with a few big caftfish that are not effective in controlling the tilapia proliferation. Macharia --- On Wed, 19/11/08, William Leschen <william.leschen@stir.ac.uk> wrote:

From: William Leschen <william.leschen@stir.ac.uk> Subject: [Sarnissa-stakeholders] Gender control for tilapia production To: "sarnissa-stakeholders Mailing List" <sarnissa-stakeholders@lists.stir.ac.uk> Date: Wednesday, 19 November, 2008, 11:58 AM From French forum

Dear all,

We all know the importance of sex control for tilapia production in the majority of the numerous farming conditions of this species group. It is not necessary to remind you all that numerous techniques have been used up till now (hybridisation), or is more classically used for sex control such as manual sexing, hormonal inversion and use of YY males. Each of these techniques has been often discussed showing their advantages and disadvantages. We all know farmers who use one or another approach depending on his constraints which are essentially the cost, the facility for its use and its efficiency.

However, it is harder to have a relative estimation of which farmers used which approach.

Would you share this information telling us if:

you use mainly a) manual sexing, b) hormonal inversion, c) off-springs of YY males, d) hybridisation, and mentioning which rearing conditions you are using (monoculture, polyculture, extensive or semi-intensive conditions). Or do you use predators and if it is the case which species do you use (Hemichromis, Heterobranchus, Clarias, Lates)? Finally, what is the main justification of your choice?

Thank you very much,

Helena D'Cotta and JF Baroiller

___________________________________

Dr. Helena D'Cotta

CIRAD-PERSYST

Aquaculture Research Unit, TA B-20/A, Bur.A18 Campus International de Baillarguet

34398 Montpellier cedex 5, France

Tel : 33 - (0) 467593951; Fax : /3825

dcotta@cirad.fr<mailto:dcotta@cirad.fr>

http://aquatrop.cirad.fr/

PS from Will - See video clip (link below) of Helena and Jean Francois at work.

Please note clip is in a section of main news report

http://minilien.com/?aPNxm6nYpr

http://jt.france3.fr/regions/popup.php?id=e31a_invite&video_number=0

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