Male Guppy Reproduction Interaction with Female Guppies

Abstract

Guppies in the streams of Trinidad have sparked curiosity throughout the biological field. At the head of the streams there is generally only one species of predators that are eating and are a threat to guppies, even though this species are generally slow. Down along the streams there is a larger population of predators with up to as many as seven different species of predators to guppies, while eating on average as many as three guppies per hour. In the part of the streams with more predators, the male guppies have less variation in color, while in the part of the stream with only one species of predator; the males are more likely to be more brightly colored and vibrant. We originally hypothesized that females were more attracted to the males that were more colorful and stood out in their environment, and that the males would be more attracted towards the females of larger size and more color, because larger size means that they are more likely to successfully produce offspring, thus making the males successful, and the color would attract the males simply because the males could see the brighter colored females better than the bland ones (French I14.1). As it turns out, males show discrimination towards females of smaller size, probably because females of larger size produce more offspring (Benz 2).  We started by testing with a single male in a fish tank by itself, there were three sections in the tank: The left, the right, and the middle. The middle was the zone where there was not going to be any female models. We did trials that lasted five minutes each, we had two stopwatches, one for the left side and one for the right; we would start the timer when the male entered a side, and we would stop it when he left a side. We tested the interest of the males by having a control model of a plain color and another model of a different color and size, we placed them in the tank during each five minute trial and observed and recorded any sexual behaviors that males exhibited towards the female models. We found that the males didn’t show much different reactions toward the control and the experimental groups, we didn’t really get much data that proves or disproves or hypothesis.