Changes in response to olfactory cues across the ovulatory cycle in brook sticklebacks, Culaea inconstans

Previous research has shown that female brook stickleback are attracted to the scent from conspecific males. In this paper, I show that a female's response to the male-based cue changes depending upon the stage she has reached in her ovulatory cycle. On the day of ovulation, when the female was ready to spawn, she was strongly attracted to the scent of conspecific males, and even performed the species-specific courtship/receptive display (head-up, sink to the bottom and remain stationary) in response to the cue. Within 24 h of spawning, the female had begun to decrease her courtship response and move away from the cue, and by 48 h she had stopped courting completely and was spending most of her time on the control (water-drip) side of the tank. Upon ovulating a second time, she was again attracted to the scent and began courtship behaviour. This represents the first experimental demonstration of a female teleost showing a change in responsiveness to male-based odours across her ovulatory cycle similar to that displayed by female mammals.