Sexual Selection of Poecilia reticulata: Effect of Female Caudal Fin Size on Male Preference

Abstract

Many organisms have developed certain characteristics to make themselves more attractive as part of sexual selection. Guppies, Poecilia reticulata, have distinct mating behaviors and characteristics that allow them to be easily observed. Our goal was to explore the effects of different female characteristics on male mate choice. We hypothesized that male guppies would be more attracted to female guppies with smaller caudal fins because it would be easier to access the female genitalia. In order to test this, we set up a tank with one male guppy and two female models with different size caudal fins. We then recorded any courtship behaviors displayed by the male as well as the amount of time spent near each model over ten five-minute trials. We found no courtship behavior displayed and no interest shown in the models. Future studies might look for ways to make the models more realistic to expand upon our findings.