Lovesick Guppy: Effects of Immunity on Male Mate Preference

Abstract

In this experiment, we studied how the presence of a visibly-healthy female guppy model and the presence of a visibly-diseased female guppy model would affect the sexual selection of male Poecilia reticulata. Male guppies display a number of sexual behaviors to attract females, and while many experiments conducted have tested their preferences to color or size, we tested the presence and absence of immunity in female guppies by using symptoms from Ichthyophthirius multifiliis. We predicted that the male guppies would display more sexual behaviors towards the healthy female models, which would indicate that they preferred a female guppy without visible symptoms of the “ich” disease. Our hypothesis was not supported, as the male guppies showed more interest in the diseased model than the healthy control model. However, while the male guppies showed more interest in the diseased model, they ultimately held little interest in either and instead spent most of their time in the no-choice zone of the tank, therefore the results are inconclusive.