Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.1/3836
Título: Why do winners keep winning? Androgen mediation of winner but not loser effects in cichlid fish
Autor: Oliveira, R. F.
Silva, A.
Canario, Adelino V. M.
Palavras-chave: Social experience
Winner effect
Data: 2009
Editora: The Royal Society
Citação: Oliveira, R. F.; Silva, A.; Canario, A. V. M. Why do winners keep winning? Androgen mediation of winner but not loser effects in cichlid fish, Proceedings of the Royal Society B-Biological Sciences, 276, 1665, 2249-2256, 2009.
Resumo: Animal conflicts are influenced by social experience such that a previous winning experience increases the probability of winning the next agonistic interaction, whereas a previous losing experience has the opposite effect. Since androgens respond to social interactions, increasing in winners and decreasing in losers, we hypothesized that socially induced transient changes in androgen levels could be a causal mediator of winner/loser effects. To test this hypothesis, we staged fights between dyads of size-matched males of the Mozambique tilapia (Oreochromis mossambicus). After the first contest, winners were treated with the antiandrogen cyproterone acetate and losers were supplemented with 11-ketotestosterone. Two hours after the end of the first fight, two contests were staged simultaneously between the winner of the first fight and a naive male and between the loser of first fight and another naive male. The majority (88%) of control winners also won the second interaction, whereas the majority of control losers (87%) lost their second fight, thus confirming the presence of winner/loser effects in this species. As predicted, the success of anti-androgen-treated winners in the second fight decreased significantly to chance levels (44%), but the success of androgenized losers (19%) did not show a significant increase. In summary, the treatment with anti-androgen blocks the winner effect, whereas androgen administration fails to reverse the loser effect, suggesting an involvement of androgens on the winner but not on the loser effect.
Peer review: yes
URI: http://hdl.handle.net/10400.1/3836
DOI: http://dx.doi.org/10.1098/rspb.2009.0132
ISSN: 0962-8452
Aparece nas colecções:CCM2-Artigos (em revistas ou actas indexadas)

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