Isopoda is an order of crustaceans. Members of this group are called isopods and include both aquatic species, and terrestrial species such as woodlice. 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 called the marsupium.
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.
Mexistenasellus is a genus of isopod crustaceans in the family Stenasellidae.
Onchotelson is a genus of isopod crustaceans in the family Phreatoicidae, which is endemic to Tasmania. It contains two species, both of which are listed as vulnerable on the IUCN Red List:
Proasellus is a genus of isopod crustaceans in the family Asellidae. Two of its species, P. parvulus and P. slovenicus, are Slovenian endemics which are listed as vulnerable species on the IUCN Red List.
Sphaerolana is a genus of isopod crustaceans in the family Cirolanidae, all of which are endemic to Mexico.
Uramphisopus is a monotypic genus of isopod crustaceans in the family Phreatoicidae. The only species is Uramphisopus pearsoni. It is only found in Brandum Bay basin in the north of Great Lake, Tasmania.
The Cymothoidae are a family of isopods in the suborder Cymothoida found in both marine and freshwater environments. Cymoithoids are ectoparasites, usually of fish, and they include the bizarre "tongue-biter", which attaches to a fish's tongue, causing it to atrophy, and replaces the tongue with its own body. Ceratothoa oestroides is one of the most devastating ectoparasites in Mediterranean aquaculture. Around 40 genera and more than 380 species of cymothoid are recognised. Species of the Cymothoidae are generally found in warmer waters and rarely in the cool and cold climates.
Ceratoserolis is a genus of isopods in the family Serolidae from the Southern Ocean around Antarctica and some Sub-Antarctic Islands. They prefer to live on soft bottoms and range of least between 24 and 950 m (80–3,120 ft) in depth. They are superficially similar to the unrelated, extinct trilobites and reach up to about 8 cm (3.1 in) in length. They were once considered to be part of the genus Serolis and for a long time only Ceratoserolis trilobitoides was recognized. The validity of the other species has been disputed, but there are some morphological and genetic differences between them and C. trilobitoides, and there are indications that additional, currently unrecognized species of Ceratoserolis exist.
The Asellidae are a family of isopod crustaceans, one of the largest families of freshwater isopods, living in both epigean and hypogean habitats in North America and Europe.
Cirolanidae is a family of aquatic isopods.
Asellus is a genus of isopod crustaceans in the family Asellidae.
Phreatoasellus is a genus of isopod crustaceans in the family Asellidae. It contains the following species:
Serolidae is a family of isopod crustaceans. The family encompasses 22 genera with 109 species. These species are exclusively marine and are distributed across the marine realms as follows: one species can be found in the Temperate Northern Atlantic, one species in the Temperate Northern Pacific, seven species in the Tropical Atlantic, six species in the Central Indo-Pacific, 16 species in Temperate South America, one species in Temperate Southern Africa, 20 species in Temperate Australasia, and 31 species in the Southern Ocean.
Scleropactidae is a family of woodlice, with a predominantly Gondwanan distribution. It contains the following genera:
Bragasellus is a genus of crustaceans in the family Asellidae. It is endemic to Spain and Portugal.
Bragasellus lagari is a species of crustacean in the family Asellidae. It is endemic to Portugal.
Bragasellus lagarioides is a species of crustacean in the family Asellidae. It is endemic to Spain.
Bragasellus meijersae is a species of crustacean in the family Asellidae. It is endemic to Spain.
Bragasellus peltatus is a species of crustacean in the family Asellidae. It is endemic to Portugal.
