In Poecilia reticulata, How Does the Body Width Size of the Female Affect the Mate Attraction?

Abstract

Poecilia reticulata, often referred to as guppies, are ideal subjects to research sexual selection. Their courting behaviors are easily recognizable and their varying size, shape, and color allow for easy manipulation of studies. For our experiment, our group conducted ten trials with ten individual male guppies to measure their courting behaviors when introduced to female guppy models. Our female guppy models consisted of a control model and an experimental model, which was altered to have increased width. Our study revealed that the courting behavior of the guppies, specifically biting, was higher with the experimental model, and the time spent with the experimental model was higher than the control model. Our hypothesis, which was that the male guppies would prefer the larger female model to the control model, was supported. Our group concluded that male guppies will select females with greater body widths because the larger body conveys larger egg sizes and the opportunity for higher fertility rates with more offspring. Because the overall goal of organisms is to increase their fitness, male guppies favor the females with larger body widths.