Isopoda is an order of crustacean, which includes woodlice and their relatives. Members of this group are called Isopods and include both terrestrial and aquatic species. 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 superorder Peracarida is a large group of malacostracan crustaceans, having members in marine, freshwater, and terrestrial habitats. They are chiefly defined by the presence of a brood pouch, or marsupium, formed from thin flattened plates (oostegites) borne on the basalmost segments of the legs. Peracarida is one of the largest crustacean taxa and includes about 12,000 species. Most members are less than 2 cm (0.8 in) in length, but the largest is probably the giant isopod which can reach 76 cm (30 in). The earliest known perecaridian was Oxyuropoda ligioides, a fossil of which has been found dating to the Late Devonian of Ireland.
A gribble /ˈgɹɪbəl/ is any of about 56 species of marine isopod from the family Limnoriidae. They are mostly pale white and small crustaceans, although Limnoria stephenseni from subantarctic waters can reach 10 mm (0.4 in).
The Valvifera are marine isopod crustaceans. Valviferans are distinguished, however, by the flat, valve-like uropods which hinge laterally and fold inward beneath the rear part of their bodies, covering the pleopods. Some species are omnivorous, and serve as effective scavengers in the economy of the sea.
Flabellifera is a former suborder of isopod crustaceans. It is a polyphyletic or paraphyletic group, and contained over 3000 species. Its members are now placed in the Sphaeromatidea and Cymothoida.
Callianassa is a genus of mud shrimps, in the family Callianassidae. Three of the species in this genus have been split off into a new genus, Pestarella, while others such as Callianassa filholi have been moved to Biffarius. The genus is named after the Nereid of the greco-roman mythology.
Sphaeromatidae is a family of isopods, often encountered on rocky shores and in shelf waters in temperate zones. The family includes almost 100 genera and 619 known marine species. Within these genera, there are groups that share distinctive morphologies; further research may reclassify these genus-groups as separate families.
Epicaridea is a former suborder of isopods, now treated as an infraorder in suborder Cymothoida. They are ectoparasites that inhabit other crustaceans, namely ostracods, copepods, barnacles and malacostracans. Epicarideans are found globally. Epicaridea are generally less well researched than other isopods.
Pentidotea wosnesenskii is a marine isopod which lives on seaweed on rocky shores along the British Columbia and Washington coastlines, as far south as San Francisco. It can often be found hiding under rockweed in the intertidal zone, and can be found in depths up to 919 metres (3,015 ft). It was described as Idotea wosnesenskii in 1851, by Johann Friedrich von Brandt, and is named after the Russian biologist Ilya G. Voznesensky. The isopod grows up to 4 centimetres in length and is usually green in colour.
Asellota is a suborder of isopod crustaceans found in marine and freshwater environments. Roughly one-quarter of all marine isopods belong to this suborder. Members of this suborder are readily distinguished from other isopods by their complex copulatory apparatus. Other characteristics include six-jointed antennal peduncle, the styliform uropods, the fusion of pleonites 5, 4 and sometimes 3 to the pleotelson, and absence of the first pleopod in females.
Cymothoida is the name of a suborder of isopod crustaceans with a mostly carnivorous or parasitic lifestyle. It contains more than 2,700 described species in four superfamilies. Members of the suborder are characterised by their specialised mouthparts which include a mandible with a tooth-like process which is adapted for cutting or slicing.
Sphaeromatidea is a suborder of isopod crustaceans.
Phoratopus remex is a species of isopod crustaceans known from only two specimens, and first described in 1925 by Herbert Matthew Hale (1895–1963). It lives on the continental shelf at Encounter Bay and Fowlers Bay, South Australia. It is so unlike all other isopods that it is placed in its own family, Phoratopodidae and suborder, Phoratopidea.
Agnaridae is a family of woodlice. They were formerly considered part of the Trachelipodidae, but were moved from that family to Porcellionidae in 1989, and then placed as a separate family in 2003.
Serolidae is a family of isopod crustaceans, containing the following genera :
Glyptonotus antarcticus is a benthic marine isopod crustacean in the suborder Valvifera. This relatively large isopod is found in the Southern Ocean around Antarctica. It was first described by James Eights in 1852 and the type locality is the South Shetland Islands.
Scutuloidea maculata is a species of marine isopods in the family Sphaeromatidae, first described by Charles Chilton in 1883. No subspecies are listed in the Catalogue of Life.
Brucerolis is a genus of isopods in the family Serolidae, found in the Southern Ocean.
Brucerolis brandtae is a species of isopods in the family Serolidae, found in the Southern Ocean in the waters around New Zealand.
Brucerolis nowra is a species of isopods in the family Serolidae, found in marine waters off Nowra in New South Wales.
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