The Arthropod Phylum

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Woodlice are members of the Arthropod phylum and are known as terrestrial isopods, a group which has a segmented body with jointed limbs attached to a rigid exoskeleton (Paoletti and Hassall, 1999; Sutton, 2013). They tend to be between 1.2mm and 30mm in size and are a dark brown or slatey colour (Paoletti and Hassall, 1999; Sutton, 2013). Woodlice are soil detritivores and are important decomposers of leaf litter as they utilise around 10% of annual leaf litter, which potentially can increase the surface of leaf litter available to microorganisms for further decomposition by a factor of four (Souty-Grosset et al., 2005). The most common habitat for woodlice is within damp, dark conditions, under rocks or within rotting wood (Sutton,…show more content…
For this experiment, one woodlice was placed in a maze and was forced to go left or right by placing Perspex blocks to obstruct the opposite turn to that chosen: this forced turn and the next freely chosen turn the woodlice made were recorded. The experiment was then repeated with 14 other woodlice; however, to avoid any of the woodlice following the path of the previous subject, for each new woodlouse the maze was randomly reorganised and the initial forced left or right turn was alternated. The third experiment was to investigate if the woodlice responded to conspecific odour. This experiment used a Y-maze that had gentle streams of humid air passing over paper which had been exposed to other woodlice for a few days. The direction of travel chosen by the woodlouse when it reached the Y-junction, and its speed of movement in mm /second were recorded. This experiment was then repeated 5 times, but after each run the exposed filter paper was replaced. The results of all experiments were recorded and the data produced from the second and third experiments for the whole group were combined to give a large data set. Results Data sets need to be checked to see if they have normal distribution and if the data has homogeneity of variance, before any statistical tests are carried out to assess whether the data is parametric or non-parametric. The test for normal distribution is to run a histogram using a statistical programme, such as SPSS, and to
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