Guppy Report

Guppy Report

Introduction: Guppies are fish that derive from the tropical streams of the tip of South America. These fish are commonly known for their vivid blueprint of color, ranging from a bundle of color to scarcely any at all. This begs the question of why they differ so much from one another and why these brightly colored fish vary in amounts of external color depending on where they are located. In regards to determining the answer to this question, an experiment was conducted to answer our hypothesis of survival: The male guppies with the brighter colors have managed to survive with less predator fish, Cichlid A, around; male guppies in other locations have had to involuntarily lighten the magnitude of their colors in order to survive around these predator fish. Experimental design helped us test our hypothesis by allowing us to run through a typical male guppy life span and see what happened when male guppies with bright or dim colors were exposed to more predator fish.

Methods: In performing our experiment, there were necessary actions that needed to be put in place. The controls for this included environment, population, and food supply. We needed to create a proper environment for the guppies to culminate in. We first put the same number of guppies in each tank as well as the same amount of food. As we progressed onto the other tanks we increased the number of Cichlid A that were in each tank. We did this over a period of 120 days since that was the maximum life span of the guppies.

Results:

Each tank started with 46 guppies. The data collected below reports the average spot pattern in male guppies in each tank, relative to the number of Cichlid A also inhabiting the tank.

Number of Cichlid A 0 4 8 16

Spot Pattern 8-10 6-8 12-14 4-6

Percentage with recorded spot count 50 52 50 50

Conclusion:

In this experiment, the goal was to determine whether or not the predatory fish, Cichlid A, were the reason that some male colonies had less spots than other male colonies. This test was chosen in order to discover a reason as to why the upper streams, which had predatory fish, but no Cichlid A, were full of male guppies with vibrant color patterns that had an average of 14-16 spots, while the lower streams, which contained both Cichlid A and Cichlid B, contained males with very low spot counts. In order to test the hypothesis that Cichlid A were a threat to the guppies survival causing them to decrease their spot counts, multiple tests were run in which 46 male guppies were