The Concept of Kinesis and Taxis on Pill Bugs - Lab Report Example

Pill bug lab In this lab, two different experiments were performed to explore the concept of kinesis and taxis on pill bugs. This acts as a basis for determining how pill bugs sense in their environment and what they can sense. The first experiment involved subjecting pill bugs to two sets of same environmental conditions, wet and wet, in order to determine if there is a difference. It was observed that there is a significant difference in the way pill bugs respond to each of these two identical conditions. The second experiment involved giving pill bugs a choice between dark or light chambers, whereby they were allowed to move freely. In this case, most of the pill bugs moved towards the moist chambers. The results were in line with the concept that the body structure of pill bugs is responsible for their response to environmental stimulus. Pill bugs breathe through gills, which make them to rely on moisture for survival; otherwise they have to rely on their crevices. Generally, the purpose of the lab was to study behavior of pill bugs in their environment. Introduction Animals exhibit orienting behavior by using compass directions to move in a specific direction to a given point when it reaches its desired destination. Intuitively, the direction in which they travel is a subject to features presented by their environment. This forms the basis for taxis and kinesis, in animals, given that an environment stimulus influences the direction of movement. Orienting behavior is of particular significance to animals in that it allows them to reach their desired destination (for food or escaping dangerous conditions). The case is best illustrated by pill bugs, which exhibit orienting behavior, when they escape from dry conditions to moist conditions. This happens because pill bugs have gills which make them prefer moist environments; otherwise, in dry conditions, they would be deprived. Further, the barely waxy outer shell of a pill bug diminishes its ability to prevent desiccation. Further, the barely waxy outer shell of a pill bug diminishes its ability to prevent desiccation. Pill bug is in the family of woodlice and the order is isopoda. This identification is what gives pill bugs their ability to coil up into a ball hence their name roly polies. The case explains why when a pill bug is moved to a drier region it will start finding its way to underneath a log; otherwise, it will end up coiling and ultimately dying. Pill bug also prefers dark places, where there is no sunlight, to avoid drying out. Besides their gills, pill bugs also utilize their antenna to achieve orientation by sensing their way to the destination (Moriyama, 2014). Since they do not have developed eyes, younger pill bugs depend on their antennas until they reach adulthood. Proximate reasons for orientation, in pill bugs, include temperature and humidity while the ultimate causes include survival and reproduction. Evidently, taxis and kinesis controls the movement of pill bugs in their environment. The major objective of this report is to study orienting behavior of pill bugs thereby exploring how they exhibit kinesis and taxis. Moriyama (2014) asserts that kinesis refers to the random movement as the result of an environmental stimulus. It is worth noting that the animals normally move in relation to given stimulus, and not towards or away from the same. In pill bugs, kinesis is notable from their characteristic rapid movement when in dryness and slow in humid conditions. For taxis, the animal’s movement is towards or away from the stimulus. In which case, pill bugs move away from the light places to the dark zones to avoid drying out. This is illustrated the moment after turning a rock, the pill bugs would be crawling around. Due to the change to a “light” environment after being exposed, a few minutes after will see the organisms coiling up and starting to leave the area. Because of their preference for darkness over light environment, pill bugs will move towards the direction of a shade, especially that under a leaf, to get a dark condition. One of the specific objectives of the lab is to determine whether pill bugs experience a difference in response to two similar conditions. Since study shows that pill bugs prefer wet conditions, there is need to determine if there is an external condition besides humidity that would affect their movement. The variables to be used are two similar conditions, wet and wet. The similar conditions would help in confirming if there is any significant difference exhibited. The second objective is to explore response of pill bugs to dark/light choice chambers. In this case, the variables to be used are dark and light choice chambers, which will help in confirming if there is any significant difference witnessed. Given, the animals prefer dark/moist environment, need arises for confirming this through allowing them to move freely in the chamber. Hypothesis Experiment 1 H0 - If pill bugs are presented with two sets of the same environmental conditions, then there will be no difference in response to these conditions H1 - If pill bugs are presented with two sets of the same environmental conditions, then there will be a significant difference in their response to these conditions. In this case, the dependent variable is the number of pill bugs choosing between the two wet conditions. The independent variable is the wetness of the conditions. The control of this experiment was the number of pill bugs found in each set of conditions. This control acted as the basis for comparing the two set of conditions, to explore how pill bugs respond to its environmental stimulus. The number helps in exploring the preference of pill bugs since it gives the frequency found on each side of the choices. The independent variable is the wetness of the conditions. The two wet conditions suit this study since they are environmental stimuli that are likely to affect the response of pill bugs in their environment. Experiment 2 If pill bugs prefer a moist, dark environment, then when they are randomly placed on both sides of dark/light choice chamber and allowed to move freely for 10 minutes, most will be on the dark side. The independent variables are the light and dark areas in the chamber. In this case, the dependent variable is the number of pill bugs choosing in dark/light chamber. This fits in confirming the hypothesis of the experiment: If pill bugs prefer a moist, dark environment, then when they are randomly placed on both sides of dark/light choice chamber and allowed to move freely for 10 minutes, most will be on the dark side. Procedure Materials Two shoe boxes measuring 11’’ wide, 4’’ deep and 7’’long Parchment paper 6 tablespoons of deionized water 10 pill bugs Method Experiment 1 Acquired two shoe boxes 11’’ wide, 4’’ deep, and 7’’ long, to act as chamber choices, and labeled one “control” and the other “treatment”. Each box was completely covered with parchment paper. The parchment paper was moistened with deionized water. 10 pill bugs were placed inside the chambers and allowed to move freely. After every 5 minutes, the pill bugs were monitored based on where they were and what they were doing. Experiment 2 Two shoe boxes 11’’ wide, 4’’ deep, and 7’’ long were acquired, to act as chamber choices. Each box was completely covered with parchment paper but this time round dark construction paper was used to cover one of the chambers. While both were kept moist, the dark construction paper was labeled “dark” while the uncovered was labeled “light”. Results Experiment 1 CC1 CC2 ∑X1 = 111 ∑X2 = 89 ∑X21 = 667 ∑X22 = 447 Mean = 111/20 = 5.55 mean = 89/20 = 4.45 = 667 - 616.05 = 50.96/19 = 2.68 Fcal = 1 ‹ Ftab = 2.51 = 50.95/19 2.68 5.55 – 4.49 2.68 1.63)(.316 1.1/0.51508 = 2.13 = T calculated 2.021 = T tab 2.11 › 2.021 We can reject the null hypothesis in favor of the alternative hypothesis; they had preference to one side. CC1 CC2 ∑X1 = 95 ∑X2 = 105 ∑X21 = 485 ∑X22 = 585 Mean = 95/20 = 4.75 mean = 105/20 = 5.25 585 – 1052/20 (585 – 551.25)/19 S21 = 1.78 S21 = 1.78 Fcal = 1.78 ‹ Ftab = 2.51 4.75 -5.25 1.78 1.33 x 0.316 = -1.19 Tcal -1.19 ‹ 2.021 There is no significant difference since T calculated is less than the T tab CC1 CC2 ∑X1 = 99 ∑X1 = 101 ∑X21 = 509 ∑X22 = 529 Mean = 99/20 mean = 101/20 = 4.95 = 5.05 S21 = 509 – 992/20 529 – 1012/20 509 – 490.05 529 – 510.05 18.95/19= 0.997 18.95/19 = 0.997 Fcal = 1 ‹ Ftab = 2.51 37.873/38 = .315 Cc1 Cc2 ∑X1 = 100 ∑X2 = 100 ∑X21 = 528 ∑X22 = 528 Mean = 100/20 = 5 Mean 2 = 100/20 = 5 Variance 1 528 – [(100)2/n 528 – [(100)2/20 528 – 500 = 28 S21 =28/19 = 1.47 Variance 2 528 – [(100)2/n 528 – [(100)2/20 528 – 500 = 28 S21 =28/19 = 1.47 1.47/1.47 = 1 F –cal F table 1 ‹ 2.51 Experiment 2 ∑∑X2 = 17 + 41 + 47 = 183 + 159 + 153 ∑(∑X2)/n = (13.4)2/20 (59.7)2/20 (26.9)2/20 (29.9)2/20 (54.6)2/20 (44.5)2/20 (55.7)2/20 8.978 178.2945 36.18 44.7` 144.058 97.24 155.12 42.5/20 = 90.31 = 759.79 A – B = 40.21 327.32/160 = 669.53 B – D = 759.79 – 669.53 = 90.26 A – B = 40.21 A – D = 130.42 Fratio = 48.73 › 2.01 Since F calc is greater than the F-tab meaning the null hypothesis should be rejected. In which case, this shows that all of the means or most of the means are different. Discussion and conclusion The first experiment testing the choice of pill bugs based on wet/wet conditions indicates that there was a significant difference in the number of pill bugs found in each container. The null hypothesis was rejected indicating that the pill bugs had preference for one side. Intuitively, it is true that if pill bugs are presented with two sets of the same environmental conditions, then there will be a significant difference in their response to these conditions. This proved that apart from the wet/wet condition, usually preferred by the pill bugs, there were still other conditions acting as stimulus for their movement. This problem was squarely solved by introducing other variables, that is, light and dark conditions for experiment 2. The ANOVA one way test was used to calculate the Fratio thereby helping to confirm if there is any significant difference. In which case, the null hypothesis stating that there were no significant differences in the mean between the two groups was rejected because the Fratio was more than the F critical. The Fratio confirms that the first group is strongly different from the second group (Matsuno & Moriyama, 2012). The results confirmed that if pill bugs prefer a moist, dark environment, then when they are randomly placed on both sides of dark/light choice chamber and allowed to move freely for 10 minutes, most will be on the dark side. The Waller-Duncan -ratio was also instrumental in supporting the ANOVA test carried out. It shows that the difference between the two means is significant with reference to the samples size. Generally, for experiment two most of the pill bugs were found in the muddy environment on the dark areas. However, they steered away from the light areas. While observing their movements, most burrowing was exhibited in the dark areas. Besides, for the light environment, the pill bugs were seen to clump together in need to preserve their moisture and keep them away from drying out. The damp environment with dark area (2) acted as the most preferred transition area as most of the pill bugs took this as their favorites. This was a confirmation to the scientific notion that pill bugs have preference for dark moist and humid environments (Matsuno & Moriyama, 2012). It is worth noting, that the comparison purposes were made successful as seen in similar behaviors witnessed by the pill bugs throughout the experiments. In the process of exploring new area, most of the pill bugs were found in the dark moist places, as opposed to light place. In fact, at the start of the experiment, as shown by the graph, most of the pill bugs were found in the light areas but eventually ended up choosing the dark areas in the long run. In all the three environments, fewer pill bugs were found in light wet environment, where dirt was nearly in suspense. This is confirmed by the graph which shows absence of activity in the light wet environment. In essence, the pill bugs only need moisture and not too much water. Pill bugs also utilize their antenna to achieve orientation by sensing their way to the destination. Since they do not have developed eyes, younger pill bugs depend on their antennas until they reach adulthood. Considering that pill bugs required moist condition for their living, there was an earlier assumption that the behavior would be the same for the two wet conditions, in first experiment. Indifferent to this presumption, the two conditions were inhabited by different number of pill bugs. A conclusion was drawn indicating that the pill bugs preferred one wet side to another. This behavior might have come across because of the different environmental conditions that the two were placed. Environment was more oriented to the light, thereby making the pill bugs to focus on escaping (Bashir et al, 2013). The dark area, presented the wet condition two allowed most of the pill bugs to seek for this are since it provided a chance for making them moist and preventing desiccation. Further, most pill bugs chose to station themselves at the end of the box where their orientation to light was poor. According to Dunn Gary, the corner of the box would favor inhabitation by the pill bugs since it acts as a dark confined area. From the above, it is proper to make a conclusion that pill bugs exhibited taxis when they moved towards the darkest areas of the box while steering away from the light area. Further, the animals mostly moved towards the damp and dark environments, another sign of taxis, while a few were found in the light sections. Kinesis was witnessed when the pill bugs moved rapidly across at the instance when they were initially placed in the shoe box. The clumping nature exhibited by the pill bugs also illustrates their association to kinesis. As Raham states in his article, pill bugs are likely to gather and stay in cluster. However, it is worth noting that the rapid movement exhibited at the start of the experiment was not any normal but should be considered a reaction to environment stimulus. This is because the pill bugs were placed in a new environment; different from the one they were initially found. This cannot be taxis since the movement was not in any way towards or away from stimulus. The response, in this case is classified as kinesis since the pill bugs were moving in relation to stimulus exhibited in the new place. The hypothesis for experiment two was that the pill bugs will choose dark moist environment over the others, and based on the calculations, this was correct. Despite this, the assumption that the pill bugs will not favor the dries environment was found to be false. This is because the experiment did not consider other factors which the pill bugs might have exhibited, such as their ability to escape. In which case, the pill bugs can visit the driest place within any given time, with the consideration that they can escape whenever there is onset of a worst scenario. The nature of the lab experiment also acted as a source of shortcoming of the study. Naturally, the purpose was to explore responses witnessed by pill bugs when placed in various environments, specifically with reference to moisture and dark/light conditions. The lab was successful in showing that the animals prefer dark moist environment over light moist but poor preparation was more conspicuous as a weakness (Millot et al, 2014). In the event of achieving the above objectives, the experiment had to be revised and restarted because of the unnecessary errors arising from the poor preparation. The initial plan was to come up with two different experiments through using grass and dirt. This plan did not work in line with the objectives since it constituted many variables that would only make the lab complicated and less specific. Further, this plan could not work because of the amount of water which could have been needed to make the environments moist. Upon the realization, everything had to be changed by dropping grass out of the experiment and also changing the measurements that were already taken. However, the success of the experiment was much evident in the thorough research done on the subject. Relevant information were obtained regarding the relationship between pill bug and its environment. This provided basis for educated predictions about the subject matter thereby eliminating chances for any unusual results. The results were in line with the concept that the body structure of pill bugs is responsible for their response to environmental stimulus as stated by Gonzalez et al (2014). Pill bugs breathe through gills, which make them to rely on moisture for survival; otherwise they have to rely on their crevices. The phenomena of huddling together were attributed to these crevices. The case is best illustrated by pill bugs, which exhibit orienting behavior, when they escape from light moist conditions to dark moist conditions. This happens because pill bugs have gills which make them prefer moist dark environments; otherwise, in light conditions, they would be deprived. Further, the barely waxy outer shell of a pill bug diminishes its ability to prevent desiccation. The case explains why when a pill bug is moved to a drier region it will start finding its way to underneath a log; otherwise, it will end up coiling and ultimately dying. Appropriate improvement for this experiment is to reduce the number of independent variable to one variable to ensure that the conclusions are specific. In this case, the independent variables were three, light, dark, wet/wet; consequently, this made it difficult to makes a conclusion about the ultimate preferred environment for pill bug. This experiment was able to explain proximate reasons for orientation, in pill bugs. The proximate reasons include temperature and humidity while the ultimate causes include survival and reproduction. Evidently, taxis and kinesis control the movement of pill bugs in their environment. For future experiment, the independent variable should be reduced to one, for instance light-dark, to determine the specific stimuli. References Gonzalez, L., Hadjiosif, A. M., Hemphill, M. A., & Smith, M. A. (2014). Environmental Consistency Determines the Rate of Motor Adaptation. Current Biology, 24(10), 1050- 1061. doi:10.1016/j.cub.2014.03.049 Millot, S., Cerqueira, M., Castanheira, M., Øverli, Ø., Oliveira, R. F., & Martins, C. M. (2014). Behavioural Stress Responses Predict Environmental Perception in European Sea Bass (Dicentrarchus labrax). Plos ONE, 9(9), 1-7. doi:10.1371/journal.pone.0108800 Matsuno, H., & Moriyama, T. T. (2012). Behavioral Evidence for Internal Factors Affecting Duration Of Conglobation In Pill Bugs (Armadillidium Vulgare, Isopoda, Crustacea). Acta Biologica Hungarica, 6380. doi:10.1556/ABiol.63.2012.Suppl.2.9 Moriyama, T. (2004). Problem Solving and Autonomous Behavior in Pill Bugs(Armadillidiun vulgare). Ecological Psychology, 16(4), 287-302. doi:10.1207/s15326969eco1604_2 Bashir, Z., Kondapalli, V., Adlakha, N., Sharma, A., Bhatnagar, R. K., Chandel, G., & Yazdani, S. (2013). Diversity and functional significance of cellulolytic microbes living in termite, pill-bug and stem-borer guts. Scientific Reports, 1. doi:10.1038/srep02558 Dunn, Gary. “Minibeast Profile: Sowbugs and Pillbugs.” Minibeast Profile. Young Entomologists Society. 7 September, 2007. Read More