Meeting Abstract

P3.191  Tuesday, Jan. 6  Hormonal Regulation of Female Sexual Behavior in a Cichlid Fish KIDD, M.R.*; HOFMANN, H.A.; Univ. of Texas at Austin mrkidd@mail.utexas.edu

Female sexuality is regulated by levels of circulating hormones mediated by the preoptic-hypothalamic axis. While many studies have looked at the neurobiology, physiology or behavioral ecology associated with female sexual behavior, these different processes have yet to be integrated into a single model system. Using the cichlid fish Astatotilapia burtoni , we examined the endogenous factors that regulate female sexuality on a fine temporal scale by relating circulating hormones levels to changes in oocyte maturation and female affiliative and choice behavior. Even though females overwhelmingly chose to spawn with large males (N=95, p<0.001), their association behavior does not reflect their eventual choice until the day of spawning. In addition to the observed change in association preference, the amount of time spent in a mating bower (p<0.001) and the number of receptive circles performed (p<0.001) by a female increase sharply on the day of spawning. Temporal patterns of circulating hormones 17beta-estradiol (E2), testosterone (T), progesterone (P), and prostaglandin F2 alpha (PGF2) are consistent with those of other vertebrates, yet the occurrence of consecutive hormone peaks within only the last week prior to spawning was surprising. Additionally, while both E2 and T are thought to decrease as levels of circulating P increase, our results suggest that P and T peak at the same time (-4 days pre-spawning). The surge in testosterone precisely coincides with a dramatic increase in female aggression towards unattractive males. Finally, none of the canonical hormones associated with female sexual behavior (E2, T, P, PGF2) are elevated at the time of spawning (rather, they are in a state of marked decline). These results provide novel proximate insights into mate choice behavior.