Guppy Love: How female guppy size influences male mating behavior and selection

Poecilia reticulata , or guppies, and the ways in which they select and pursue their mates, is an important area of research for scientists studying sexual selection in fishes. This study investigates how the size of female guppies influences male guppy mating behavior and selection. Since much of the prior research regarding size and selection shows that female guppies are attracted to larger male guppies, we hypothesized that the opposite is true – male guppies are more attracted to smaller female guppies. We conducted our experiment by placing two model female guppies – one regular sized and one tiny – in a tank with a male guppy and recording the male’s courtship behaviors. We chose to use orange models because of the previous research showing that male guppies are attracted to brightly colored female guppies. Our results show that male guppies display more courtship behaviors toward smaller female guppies. The information from our experiment can be used by future scientists studying sexual selection in guppies by implementing our results regarding size with other factors, such as color and shape.