Social modulation of sex steroid concentrations in the urine of male cichlid fish Oreochromis mossambicus. | - CCMAR -

Journal Article

TitleSocial modulation of sex steroid concentrations in the urine of male cichlid fish Oreochromis mossambicus.
Publication TypeJournal Article
AuthorsOliveira, RF, Almada, VC, Canario, AVM
Year of Publication1996
JournalHorm Behav
Date Published1996 Mar
KeywordsAnimals, Behavior, Animal, Male, Perches, Radioimmunoassay, Social Behavior, Steroids, Time Factors

The relationship between urinary concentrations (free + sulfates + glucuronides) of the steroids testosterone (T), 11-ketotestosterone (11KT), 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (17, 20 beta-P) and 17 alpha, 20 alpha-dihydroxy-4-pregnen-3-one (17, 20 alpha-P), and the social behavior of males of the cichlid fish Oreochromis mossambicus was investigated. After 8 days of isolation none of the steroids were good predictors of social dominance developed after subsequent formation of all-male groups. One day after group formation dominance indexes were good predictors of the urine concentrations of all sex steroids. Dominance indexes and androgen concentrations measured after all-male group formation were positively correlated with territoriality, courtship rate, and nest size. Similar relationships were found for progestins with the exception that they were not correlated with courtship rate. All-male group formation was also accompanied by an increase in urinary sex steroid concentrations in fish that became territorial and a decrease in non-territorial fish with the exception of T, which increased in both groups. Addition of ovulating females caused steroid concentrations to return to levels near isolation, except for 17, 20 alpha-P in territorials, which underwent a large increase. Thus, social interactions may have an important modulatory effect on sex steroid concentrations in O. mossambicus.


Alternate JournalHorm Behav
PubMed ID8724173
CCMAR Authors