[The following is summarised from: http://soilbugs.massey.ac.nz/isopoda.php]
Common Names: Slaters, pill bugs, sow bugs, woodlice, Maori papapa Scientific Name: Arthropoda (Phylum) Crustacea (Class) Isopoda (Order) Oniscoidea (Suborder).
Slaters are apart of the Isopoda order, meaning they have an equal number of legs. They are also a crustacean, but unlike most crustaceans they are terrestrial opposed to marine dwellers so they fall into the Oniscoidea suborder. They have very distinct features like their elliptical flattened segmented exoskeleton and seven pairs of legs. They generally are dull in colour consisting mostly of earthy shades of grey, mottled with greens, browns and yellows. The variation amongst colours/patterns of individuals is extensive. The New Zealand variety of slaters range from several millimetres to upwards of 2 cm in length (most common length being between 1-1.5 cm). The exoskeletons of slaters are comprised of calcium carbonate making them quite rigid. The body is separated into 3 distinct regions; head, thorax and abdomen, however far less distinguishable than insects. The head is composed of a complete shield-like segment of shell with two sets of antennae, though only looks like one due to the second pair being very small, this second pair is thought to enable chemotaxis. In conjunction with antenna woodlice have two compound eyes enabling sight. Slaters have two ways in which they can exchange gases; via gills and a ‘primitive lung’. The ‘lungs’ are visible as white or pale patches upon the lower underside of the woodlice. Each ‘lung’ has a single unclosable pore that allows gases to diffuse in and out. As the pore cannot be closed, unlike insects, and their shells do not have a waxy coating (to keep in moisture) so they are at a far greater risk of desiccation and thus the humidity of their environment is a pivotal factor in regards to their survival....