Meeting Abstract
Sexual selection, the ultimate mechanism driving the evolution of sexual dimorphism in plants and animals, includes both intra and inter-sexual components. Exploring the interaction of these forces is difficult and most experimental studies tend to focus on one aspect or the other. Here, we set out to explore the interaction between intra- and inter-sexual selection pressures on mate preference in a monogamous model system. Two female convict cichlids, Amatitlania siquia, were placed into an experimental aquarium containing two compartments with a potential male mate and nest site in each, and a central neutral compartment. The females could freely move between compartments and interact with potential male mates, as well as each other, for a three-day observation period. This design allowed for simultaneous intrasexual competition between females as well as the formation of a preference between two males of similar quality. In a second experiment, the same design was used, but the two males differed in quality. We found that females demonstrated a time-based preference for males in both experiments, but that in the first experiment (size-matched males), there was no difference in preference between the two males; each female seemed to prefer one of the males. In the second experiment (size difference males), however, both females demonstrated a preference for the large male. This was evidenced by females spending significantly less time with the smaller male by the end of the experiment. This suggests that in the presence of intrasexual female competition, females may adjust their threshold for potential mates, even to the extreme level of foregoing reproduction with a low-quality male when a higher quality male is unavailable. Future work will explore how levels of female aggression may be affected by differences in male quality in this experimental paradigm.
