The effect of size on mate selection in guppies.

Abstract

Sexual selection in species tends to be a popular topic of study among scientists. Guppies are an easy
species to study for this topic as they are small, easy to care for, and easy to observe. Much study has
been done regarding the visual preferences of female guppies in sexual selection, but less so for males
(Herdman et al. 2004). This study focuses on the less studied male guppies. In this experiment we tested
whether male guppies preferred larger females or standard size females. We hypothesized that male
guppies would prefer larger females as they may find them more sexually attractive because fertility of
female guppies tends to increase with size. When a male guppy was presented with a standard size, red
female guppy and a large, red female guppy we found there was no significance difference in time spent
with each model, so we cannot conclude the male guppies prefer a certain size mate. This could be due to
various reasons, including predation.