Name: | Description: | Size: | Format: | |
---|---|---|---|---|
288.23 KB | Adobe PDF |
Advisor(s)
Abstract(s)
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.
Description
Keywords
Androgen responses Conjugated metabolites Non-invasive methods Gill diffusion Steroid excretion Urine Challenge Cichlid
Citation
Behaviour, 145, 1367-1388