Terrestrial Isopod Experiment Essay

The purpose of this lab is to observe isopods and examine their responses to a chosen factor, the preference of either a dark or light environment. From observing the responses of the isopods, the behaviors of the isopods will be decided whether they fall into taxis or kinesis. Chi-Squared test will also be calculated in order to determine whether the observed results were due to chance or preference. Terrestrial isopods are commonly known as pillbugs, sowbugs, or “roly-pollies”. These organisms are members of the Phylum Arthropoda, Class Crustacea. Isopods are omnivores that generally feed on decaying material, algae, moss and bark. Because isopods respire through gills, they are more restricted to areas with high humidity, particularly under rocks or logs, in leaf …show more content…
The experimental model in this lab represents the real habitat and system in which the isopods reside in. Isopods generally live in a habitat where they deal with the difference in dark and bright natural environments. If the isopods are exposed to only two environments, dark and bright, then the isopods will prefer the dark environments as they generally reside under rocks or logs, in its crevices. Their tendency to reside in habitats with high humidity also predicts their preference to be in darkness. The independent variable in this environment is the change in environment: dark or bright light. The dependent variable is the number of isopods in each chamber at the given time, which in this lab is every 30 seconds. Constants include the temperature of the testing room, humidity (wetness of filter paper) and source of these experimented isopods. There is no control group included for this experiment, due to the only options of light being dark and