Meeting Abstract
Julidochromis marlieri, a socially plastic African cichlid, naturally establishes pair bonds between relatively larger and more aggressive dominant females and smaller subordinate males in both the wild and in the lab. However, these fish will also form pairs with a relatively larger male and a smaller female, and exhibit a reversal of their natural sex-biased behaviors. Here we investigate the hormonal profiles associated this plastic switch in social behavior. We collected gonadal hormones and behavioral measurements from male and female J. marlieri in both dominant and subordinate conditions over several weeks. Analysis of three sex hormones—17β-estradiol, testosterone, and 11-keto testosterone—showed that 11-keto testosterone concentration correlated positively with increased dominance and aggression in both males and females, with no significant correlation found between dominance and testosterone or 17β-estradiol in either sex. This further expands the importance of 11-keto testosterone in teleost social behavior, and illuminates the appropriate hormone for further manipulation and functional analysis in J. marlieri.
