Injured Caudal Fin Appearance and Effect on Poecilia reticulata Male Mating Choice

Abstract

Mate choice is a mechanism of sexual selection that occurs in a wide variety of organisms and acts on an organism’s ability to mate and produce offspring. Among these organisms is the guppy, Poecilia reticulata, which was used in our experiment due to its easy care and popularity in the research field. For our experiment we used a two choice guppy model system using a standard body size, warm gray colored guppy and a warm gray colored guppy with an abnormal caudal fin. We hypothesized that if the female model guppy has an injured appearing caudal fin, then the male guppy will exhibit less mating behaviors than when compared to the standard female model, because the abnormality may convey lesser fitness. We found our hypothesis to be supported since the male guppy spent more average time around and exhibited greater number of mating behaviors towards the healthy appearing female guppy model when compared to the average time spent around the guppy model with the injured caudal fin.