Large or Small, Do They Love Them All? Male Guppy Preference for Female Caudal Fin Size

Abstract

In this experiment, we are testing whether male guppies are more attracted to females with larger caudal fins, also known as tail fins.  We are using a green control female model with a normal sized caudal fin and a green experimental female model with an enlarged caudal fin.  Many previous studies have been done on guppies and many results  indicate that males are more attracted to females that are larger (Lakey et al. 2015), so in this experiment, we would predict more attraction to the female model with the larger fin, as it will appear larger.  Our hypothesis was partially supported because the male guppies on average spent more time in the choice zone of the female with the larger caudal fin, but none of the males displayed any mating behaviors towards the females.  There are many factors that could cause this, and we noticed that the males spent more time looking at their reflection.