Size Does Matter: Male Guppies Preferences in Respect to Mate Size

Abstract

Male guppies are able to assess the female guppies fitness based off of size; this then allows males to be able to choose which female will allow them to have a greater reproductive benefits (Dosen et al, 2004). For this experiment we hypothesized that male guppies will prefer larger females rather than smaller females due to the male’s ability to differentiate between females that will produce offspring with higher fitness. To test this hypothesis we chose to order a large 3D printed female guppy with large fins. This served as our experimental group. We used a 40 mm regular sized grey model guppies for our control group. We chose to perform three trials a day on two different male guppies. These trials lasted for the duration of five minutes and the fish was then given a five minute break to recover.  Our results reveal that the male guppy prefers the larger female model based off the average calculated time the male guppy spent around the female models.