A sizeable matter: a study of sexual selection in male guppies

Abstract

One of the most distinct characteristics of Poecilia reticulata, the freshwater aquarium fish known as the guppy, is the behaviors they exhibit in sexual selection. They demonstrate honest signaling, which is when an organism has large, exaggerated features which signal to a potential mate that it is capable of gathering food, passing on good genes, and survive predators while bearing a large, often awkward sexual trait. Size and color are the main forms of honest signaling that guppies exhibit. Numerous studies about sexual selection in female guppies have been done; however, little research exists about sexual selection in male guppies. Our group decided to study a male guppies’ attraction to bright colors and size due to its novel nature. We hypothesized that a huge neon guppy would attract a male guppy better than a tiny guppy because the neon orange signals that she is capable of passing on good genes and her large body size indicates that she is better suited to carrying a large amount of young. We tested our hypothesis by placing a huge, neon orange 3D model of a female guppy in a tank along with a normal, average sized guppy. Our results proved to be inconclusive; the guppies did not seem to prefer a larger sized model.