Toguyeni Aboubacar, Fauconneau Benoît, Mélard Charles, Fostier Alexis, Lazard Jérôme, Baras Etienne, Kühn Eduard R., Van Der Guyten S., Baroiller Jean-François.
1997. Sexual dimorphism studies in tilapias, using two pure species, Oreochormis niloticus and Sarotherodon melanotheron, and their intergeneric hybrids (O. niloticus x S. melanotheron and S. malanotheron x O. niloticus).
In : Proceedings of the fourth international symposium on tilapia in aquaculture = [Actes du 4ème congrès international sur tilapia en aquaculture]. Fitzsimmons K. (ed.)
Autre titre : Etudes du dimorphisme sexuel des tilapias : utilisation de deux espèces pures, (Oreochormis niloticus and Sarotherodon melanotheron), et des hybrides interspécifiques (O. niloticus x S. melanotheron and S. malanotheron x O. niloticus)
Résumé : This comparative study of growth performances and sexuel growth dimorphism was conducted with fish obtained from artificial reproduction. Growth was measured weekly. The levels of sexual steroids (11-KT) and thyroid hormones (T3 and T4) was measured after 74 rearing days and at the end of the experiment (103 days). Social interactions were examined with a video camera (three sequences of one hour for each group). #O. niloticus# and #S. melanotheron# achieved the best and worst growth rates, respectively, with their intergeneric hybrides standing in between. Tilapias originating from female #O. niloticus# (pure species and hybrid 1) exhibited a significant sexual growth dimorphism, which contrasted with the situation observed in the two other groups (originating from female #S. melanotheron#), where no significant difference was measured. Male tilapias from the two hybrid groups had similar growth rates, whereas hybrid females originating from female #S. melanotheron# (hybrid 2) grew faster than those coming from female #O. niloticus# (hybrid 1). The levers of 11-KT were highest in #O. nioticus# and lowest in #S. melanotheron#. The levels in the hybrid groups were similar and intermediate between those of the pure species. By contrast, the lever of T4 was highest in #S. melanotheron#. The levels of T3 at 74 days did not differ between groups but between sexes in all four groups. At the end of the experiment, this sex-related difference was still observed in the hybrid 2 group whilst it had vanished in the hybrid 1 group. The analysis of behavioural sequences indicated that aggressive behaviours (face to face or jaw to jaw interactions, attacks with or without poursuit) first emerged among faster growing fish (#O. niloticus# and hybrid 1)
Mots-clés Agrovoc : Tilapia, Oreochromis niloticus, Sarotherodon, hybride, dimorphisme sexuel, gain de poids, contrôle hormonal
Classification Agris : L52 - Physiologie animale - Croissance et développement
Auteurs et affiliations
- Toguyeni Aboubacar
- Fauconneau Benoît
- Mélard Charles
- Fostier Alexis
- Lazard Jérôme, CIRAD-EMVT-ABEL (FRA)
- Baras Etienne
- Kühn Eduard R.
- Van Der Guyten S.
-
Baroiller Jean-François, CIRAD-EMVT-ELEVAGE-AGRICULTURE (FRA)
ORCID: 0000-0002-0992-1725
Autres liens de la publication
Source : Cirad - Agritrop (https://agritrop.cirad.fr/389863/)
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