Coloration Effects on Male Guppy (Poecilia reticulata) Courtship Behavior

Abstract

Guppies, Poecilia reticulata, have been a research animal of interest to neuroscientists, evolutionary biologists, and ethologists for several decades due to their small size, easy care, well-identified behaviors, and the plethora of early work describing their behavior and biology. The guppy species is a near perfect example of the Darwinian theory of natural selection, as more drab-colored male guppies exist in the areas with more predators because they are harder for predators to see. In the same way, the more attractive, brightly colored fish are more susceptible to predators and therefore do not have the opportunity to produce as many offspring. For this lab, we were interested in studying the mating preferences, or sexual selection process, of guppy males and why some guppies attract more mates than others in the absence of predators. By placing various 3D-printed models of female guppy fish in several tanks containing a single male guppy, the lab determined that male guppies are most attracted to brightly colored females as most courtship behaviors took place with the orange model and other brightly colored model fish. Overall, the orange model received the most variety of courtship behavior; however, the yellow model obtained the greatest number of responses. This conclusion supported the hypothesis that if a male guppy is presented with a brightly colored yellow or orange female guppy model, then he will perform more courtship behaviors than when presented with a black or more drab-colored model. The brightly colored females will attract more mates.