BIOL 123 poster

Picky Pill Bugs: Environmental Preferences of A. Vulgare Rory O’Connor, Po Nwe, Susie Mohamed, Tessa Carby, TA: Dakota Vaccaro WESTERN KENTUCKY UNIVERSITY RESULTS DISCUSSION ACKNOWLEDGEMENTS INTRODUCTION METHODS OUR STUDY Armadillidium Vulgare , more commonly referred to as the pill bug because of its capsule shape, is a species of isopod: a type of crustacean native to Europe but commonly found in North America. Only about half of all isopods are land-dwelling compared to living in freshwater. The pill bug is cold-blooded, meaning that the environment changes the body temperature that it is in; the pill bug can usually be found in cooler environments. The pill bug is also a nocturnal species and, as a result, typically dwells in the dark, hidden areas under the soil, rocks, mulch, or fallen leaves (US Department of Commerce, 2014). c Even though the female pill bug carries her young in a pouch, they are not marsupials. The pill bug has a hard-shelled exoskeleton, seven pairs of legs, and five pairs of gills. Although gills on a land-dwelling creature may seem inefficacious, they can take up oxygen through them in damp environments. This is because their gills are an evolved trait from the pill bug’s water-dwelling ancestors (What About Pill bugs? 2019). The basis of this study was to determine which of the stimuli presented was the most important for pill bugs. Pill bugs are known to like wet and dark environments. This experiment was helping us determine if either a wet or dark environment was more important for the pill bugs. We studied this by placing groups of pill bugs in a divided petri dish, one side being wet/light and the other being dark/dry. Our null hypothesis was that a wet or dark environment will have no effect on pill bug preferences. Our alternative hypothesis stated that pill bugs will prefer the dark/dry environment over the light/wet environment. Our mechanism is because temperatures above 40 prove to be lethal to pill bugs, ℃ and darker environments tend to be colder(Gibbs & Smigel 2008). REFERENCES Gibbs,AG&Smigel,JT. 2008. Conglobation in the Pill Bug, Armadillidium vulgare , as a Water Conservation Mechanism. Journal of Insect Science . 8:44. Joly, F.-X., Weibel, A. K., Coulis, M., & Throop, H. L. 2019. Rainfall frequency, not quantity, controls isopod effect on litter decomposition. Soil Biology & Biochemistry . 135:154–162. Leclercq-Dransart, J., Pernin, C., Demuynck, S., Grumiaux, F., Lemière, S., & Leprêtre, A. 2019. Isopod physiological and behavioral responses to drier conditions: An experiment with four species in the context of global warming. European Journal of Soil Biology . 90:22–30. Refinetti, R. 2000. Circadian Rhythm of Locomotor Activity in the Pill Bug, Armadillidium Vulgare (Isopoda). Crustaceana . 73:575. US Department of Commerce, N. O. and A. A. (2014, March 25). What is an isopod? Ocean Exploration Facts: NOAA Office of Ocean Exploration and Research. Retrieved March 14, 2022, from https://oceanexplorer.noaa.gov/facts/isopod.html What About Pillbugs? PNNL. (2019, October 1). Retrieved March 14, 2022, from https://workbasedlearning.pnnl.gov/pals/resource/cards/pillbugs.stm#:~:text=Pillbugs%20are%20wingless %2C%20oval%20or,have%20seven%20pairs%20of%20legs. • Thank you to Tessa Carby for completing the Introduction of the poster. • Thank you to Po Nwe for completing the Methods portion of the poster. • Thank you to Rory O’Connor for completing the Results and Our Study portion of the poster. • Thank you to Susie Mohamed for completing the Discussion portion of the poster. • Thank you to Dakota Vaccaro for the overall guidance and assistance. Table 1 Number of Pill Bugs 1m 2m 3m 4m 5m 6m 7m 8m 9m 10m 11m 12m Light Area 4 3 5 5 5 5 5 4 5 5 5 5 Dark Area 1 2 0 0 0 0 0 1 0 0 0 0 . Table 1 displays the data from Task 1 at each time interval. Number of Pill Bugs 1m 2m 3m 4m 5m 6m 7m 8m 9m 10m 11m 12m Dry Area 0 0 0 0 0 0 0 0 1 0 0 0 Wet Area 5 5 5 5 5 5 5 5 4 5 5 5 Table 2 Table 2 displays the data from Task 2 at each time interval. 1m 2m 3m 4m 5m 6m 7m 8m 9m 10m 11m 12m Light/Wet Area 0 0 1 0 0 0 0 0 0 0 0 0 Dark/Dry Area 5 5 4 5 5 5 5 5 5 5 5 5 Table 3 Table 3 displays the data from Task 3 at each time interval. Observed(O) Expected(E) O-E (O-E) 2 (O-E) 2 /E Light/Wet 0 2.5 -2.5 6.25 2.5 Dark/Dry 5 2.5 2.5 6.25 2.5 X 2 =Sum= 5 Table 4 Table 4 displays the Chi-Square calculations from Task 3 and the statistic value(highlighted). 0 2 4 6 8 10 12 14 0 1 2 3 4 5 6 Pill Bugs in Light/Wet vs. Dark/Dry Environments Light/Wet Dark/Dry Time Interval(Minutes) Number of Pill Bugs Graph 1 Graph 1 displays the plotted data from Task 3. This graph displays the pill bugs’ behaviors in dark/dry and wet/light environments. This chart shows that the pill bugs behaved as hypothesized. The null hypothesis was able to be rejected and the alternative hypothesis was accepted. There were significant results that the pill bugs preferred the dark/dry environment over the wet/light environment. The pill bugs tended to group together into clumps on the darker side, showing that having a dark environment is more important to them than having a wet environment, which pill bugs prefer. The chi-square value that was calculated further supported these findings. A value of 5 was calculated using the chi-square formula. Following the standard critical value chart, with a probability of .05 and 1 degree of freedom, our sum needed to be greater than or equal to 3.841 to reject the null hypothesis. With our chi-square value of 5, we were able to reject the null hypothesis and accept the alternative meaning there were significant findings. The pill bugs showed that they preferred a dark/dry environment over a light/wet environment.   Our initial hypothesis that hypothesized that the Pill Bugs would prefer the dark/dry environment over the wet/light environment was proven valid in accordance with our results. Our Chi-squared value further supported our hypothesis by allowing us to reject our null hypothesis by exceeding the critical value needed. Initially before we conducted our experiment, we established our hypothesis based off the fact that Pill Bugs acquire nutrients from the soil and decaying matter. This process is done under rocks, in the ground, decaying natural resources, etc. where it is naturally dark. With our previous knowledge of Pill Bugs from lab and scholarly articles, my group established the preferred habitat for survival in Pill Bugs. According to many peer-reviewed articles, Pill bugs are more active at night and prefer the dark (Refinetti 2000). Furthermore, Pill Bugs are terrestrial isopods who require a damp/ moist environment (in moderation) to respire through their gills (Leclercq-Dransart et al 2019; Joly et al. 2019). With these means of preference and survival in mind, our hypothesis was based on which stimulus Pill Bugs disfavor MORE, instead of at all. Although our experiment gives us good insight into Pill Bugs and their behaviors to different stimuli, we cannot use these results as completely valid. We only used 5 of these isopods to gather evidence, which is a very small control group. Also, these Pill Bugs were taken out of their original environment and put into our loud and crowded Biology Lab where stress, and noise levels play a crucial factor in their psychology and behavior. Moreover, they were given a measly 12 minutes to find position in the Petrie dish which again, is not a significant amount of time at all to get results valid enough to fully analyze. It is also important to note that the Pill Bugs removed from their regular habitat were only part of one sample and do not represent the species of Armadillidium vulgare. With all these factors in mind, we can improve our experiment next time by increasing the sample size, getting a variety of Pill Bugs from different locations, placing them in an environment closer to what they are used to (going out in nature), and giving a larger amount of time to move. Materials : - 1 Empty Petri dish - 5 Armadillidium vulgare (Pill Bugs) - Stopwatch - Filter paper - Black construction paper ( or any covering ) - Stopwatch - Distilled water - Lamp ( any source of light will do) Procedure : Task One: 1. Obtain an empty Petri dish and put in filter paper 2. Add the 5 pill bugs into the Petri dish. 3. Take the lamp and make sure the light is directly over the pill bugs, with the construction paper cover one half the Petri dish. 4. Turn the lamp one and using your stopwatch in intervals of one minute for 12 minutes record how many pill bugs to to the dark or light side   Figure 1. The image above shows the result of what the experiment should look like. The Biology notebook was used as the shade and the other half of the dish was left open for light to come in.   Task Two: 5. Repeat task one except add in 2-5 drops of water to one half of the Petri dish. 6. Again, in intervals of one minute record how many pill bugs went to dry or wet side.   Task Three: 7. Similar procedures used in task one and two except for task three the shaded side is to be kept dry while the lit side is wet. 8. Same is task one and two, in intervals of one minute record how many pill bugs preferred the dry but dark side rather than the light but wet side. Statistical Analysis:   A Chi-Square Analysis was calculated for each set of data after the experiments in order to find the significance of each result. The equation used was: Χ^2= ∑(Observed-Expected)^2/Expected The value we got from this was them compared to the critical value with 1 degree of freedom.