The Effect of Multiple Females on Sexual Selection in Poecilia reticulata

Abstract

We are constantly evolving our knowledge on sexual selection and how it affects a species as a whole. For the purpose of our study, we focused on Poecilia reticulata, commonly known as the guppy, and how the presence of multiple females affect the male’s preference for a mate. We hypothesized that a male would prefer a group of females as opposed to a single female simply because it would further his chance of successfully reproducing. In order to test this, we were given four female models (all standard size and true orange in color) to place in a tank with a single male guppy. Three models were placed in a vertical stack on one side of the tank with the other placed on the opposite side of the tank, each time randomizing what side of the tank each would be on. Male courtship behavior was monitored and recorded for five minutes and the process was repeated on another male guppy. The male guppies, on average, were near the group of female models longer than the single female model, yet displayed more courtship behaviors towards the single female model. While the study we created had the potential to give insight into a driving force behind natural selection, our data appeared to be rather inconclusive. We believe the inconclusiveness of this data was due to the possible stress the males endured.