Attraction of female fathead minnows,Pimephales promelas, to chemical stimuli from breeding males.

Female fathead minnows,Pimephales promelas, were attracted to water that had contained conspecific males in breeding condition. The attraction was particularly strong in the morning and occurred in both females with mature gonads and gonadally regressed females. Females were also attracted to water that had contained other females but this attraction was weaker than the attraction to breeding males and tended to occur in afternoon trials. When offered a choice, females preferred breeding male water over regressed male water or female water. Swarming behavior, in which females formed a very active group near the water inlet, occurred primarily in test locations receiving water from breeding males. Our results indicate that breeding maleP. promelas produce water-borne chemical stimuli that attract females and that females distinguish breeding male stimuli from female or regressed-male waterborne stimuli.