Social context may affect urinary excretion of 11-ketotestosterone in african cichlids

• Autor(a) principal: Hirschenhauser, Katharina
• Data de Publicação: 2008
• Outros Autores: Canário, Adelino V. M., Ros, Albert F. H., Taborsky, Michael, Oliveira, Rui Filipe
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.12/1273
• topic: Androgen responses; Conjugated metabolites; Non-invasive methods; Gill diffusion; Steroid excretion; Urine; Challenge; Cichlid

We previously investigated the androgen responsiveness of males to simulated partner and territory intrusions in five African cichlid species (Neolamprologus pulcher, Lamprologus callipterus, Tropheus moorii, Pseudosimochromis curvifrons, Oreochromis mossambicus; Hirschenhauser et al., 2004). Here we re-analysed data on 11-ketotestosterone (11-KT) levels in holding water to compare the free (presumably from the gills) and conjugated (presumably from urine and faeces) 11-KT fractions. We sampled (i) pre-test baseline control levels from individual males in social isolation and (ii) response levels released after social interactions, either with an ovulating female or a male territory intruder. In four out of five species, conjugated metabolites contributed to the observed total 11-KT responses in water during social context, which was particularly apparent in peak responsive individuals exposed to male intruders. Thus, in water from males sampled in isolation immunoreactive 11-KT seemed to derive both from gills and urine, whereas the urinary 11-KT component apparently increased in the social context, particularly when a male was challenged by a same-sex intruder. These results suggest that (i) the social context may affect urine release patterns of males and (ii) 11- KT data acquired by using fish-holding water may not simply reflect the passive transmission of steroid hormones via the gills.