Is More the Merrier? Does Group Size Affect Male Guppy Mate Selection

Guppies, Poecilia reticulata have been considered ideal for animal research due to their small size, easy care, and well- identified behaviors (Baerends et al. 1955). Our group observed sexual behaviors of male guppies and tested different group sizes to determine the preference of male guppies. To perform this experiment, we used three dimensional standard guppies, which represented the female guppies. We used three standard control models on one side of the tank to replicate a group and we used one standard control model on the other side of the tank to replicate an isolated guppy. We hypothesized that the male guppies would favor a larger group size of females because there are more potential mates compared to the one guppy on the other side. Our results show that the male guppy spent a longer period of time on the side with the single guppy, but displayed more mating behaviors towards the larger group size. Our results slightly supported our hypothesis based on the 10 trials we ran, and more research should be done to see how group size affects guppy mating.