Isopoda is an order of crustaceans that includes woodlice and their relatives. Isopods live in the sea, in fresh water, or on land. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed limbs on the thorax, and five pairs of branching appendages on the abdomen that are used in respiration. Females brood their young in a pouch under their thorax.
The Gnathiidae are a family of isopod crustaceans. They occur in a wide range of depths, from the littoral zone to the deep sea. The adults are associated with sponges and may not feed. The juvenile form is known as a 'praniza', and it is a temporary parasite of marine fish. These forms are not larvae; Gnathiidae instead become parasitic during the manca stage. Mancae of the Gnathiidae closely resemble the adult form, however they lack the final pair of pereiopods.
Porcellio laevis is a species of woodlouse in the genus Porcellio. As the species epithet laevis as well as the vernacular name "swift woodlouse" suggests, the species is capable of quick bursts of speed when provoked.
Philosciidae are a family of woodlice. They occur almost everywhere on earth, with most species found in (sub)tropical America, Africa and Oceania, and only a few in the Holarctic.
A woodlouse is any crustacean belonging to the suborder Oniscidea within the order Isopoda. They get their name from often being found in old wood, and from louse, a parasitic insect, although woodlice are not insects.
Trichoniscus pusillus, sometimes called the common pygmy woodlouse, is one of the five most common species of woodlice in the British Isles. It is acknowledged to be the most abundant terrestrial isopod in Britain. It is found commonly across Europe north of the Alps, and has been introduced to Madeira, the Azores and North America.
Reductoniscus costulatus is a species of woodlouse in the family Armadillidae. In the wild, R. costulatus has been found in Mauritius, the Seychelles and Hawaii, including the islands of Oʻahu and Kauaʻi and Hawaiʻi. It was discovered in the Palm House at the Royal Botanic Gardens, Kew in 1948, 1976 and 1988, and has been found in greenhouses across Europe.
Ligia is a genus of isopods, commonly known as rock lice or sea slaters. Most Ligia species live in tidal zone cliffs and rocky beaches, but there are several fully terrestrial species which occur in high-humidity environments.
Mesoniscus is a genus of woodlice, placed in its own family, Mesoniscidae, and section, Microcheta. It contains two species – Mesoniscus alpicolus and Mesoniscus graniger – that live in Central and Eastern Europe, mostly in and around caves.
Armadillidae is a family of woodlice, comprising around 80 genera and 700 species. It is the largest family of Oniscidea, and one of the most species-rich families of the entire Isopoda. Armadillids generally have a strongly convex body shape, with some rather shallowly convex. Like members of the woodlice family Armadillidiidae, armadillids are capable of enrolling into a sphere (conglobation), and are commonly known as pill bugs. Armadillids differ from the Armadillidiidae in that the antennae are fully enclosed within the sphere.
Niambia is a genus of woodlice in the family Platyarthridae. There are at least 20 described species in Niambia.
Cylisticidae is a family of woodlice in the order Isopoda. There are at least 4 genera and more than 60 described species in Cylisticidae.
Pudeoniscidae is a family of malacostracans in the order Isopoda.
Helleria brevicornis, the sole species of the monotypic genus Helleria, is a terrestrial woodlouse endemic to the islands and coastal regions of the northern Tyrrhenian sea. H. brevicornis is of interest due to its endemism, unique ecology and basal position in the suborder Oniscidea.
Deto aucklandiae is a species of seashore dwelling woodlouse from the Detonidae family. D. aucklandiae is endemic to a few subantarctic islands in New Zealand.
Alpioniscus is a southern European genus of woodlice in the family Trichoniscidae. Alpioniscus consists of two subgenera: Alpioniscus s.s. and Illyrionethes. A 2019 study used molecular and taxonomic analyses to verify the validity of the current taxonomy, resulting in the redescription of several species and the description of two new species.
Styloniscus manuvaka is a species of terrestrial isopod endemic to the islands of Rapa Nui and Rapa Iti. Its specific epithet translates roughly to "Canoe Bug" in reference to the original author's hypothesis which holds this species colonized these islands alongside ancient Polynesians via transplanted "Canoe Plants" such as Banana, Taro, and Sugar Cane. The species currently survives only as relict populations in caves. This species is in dire need of conservation, and is threatened by a combination of habitat loss, non-native species, and global climate change.
Hawaiioscia rapui is a species of woodlouse endemic to the island of Rapa Nui. The specific epithet honors Sergio Rapu Haoa, a humanitarian, archaeologist, anthropologist, and politician of Rapanui descent who aided research terms studying this species. It persists as a relict population near the mouths of caves on the island, and is in dire need of conservation. It faces threats such as habitat reduction, non-native species competition, and global climate change. Styloniscus manuvaka is the only other native Isopod on the island, and faces the same perils.
Hawaiioscia nicoyaensis is a species of woodlouse from Costa Rica. Its specific epithet is derived from the location of its type locality along the Gulf of Nicoya. It is the only known member of its genus to be found on a continent rather than a pacific island and the only one to be littoral halophilic. Furthermore, it is the only extant member of its genus not to be restricted to caves.
Eluma is a genus of woodlice in the family Armadillidiidae. The members of this genus are native to the Iberian Peninsula, Morocco, the Atlantic islands of the Azores, Canaries and Madeira, and from the west of France to the British Isles.
