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.
Curassanthura is a genus of isopod crustaceans in the family Leptanthuridae. It contains the following species:
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:
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.
Nichollsia is a genus of isopod crustaceans from India. It comprises two species:
Iais is a genus of isopod crustaceans. Iais species are found in association with larger isopods of the family Sphaeromatidae, usually on the ventral surface of the larger animal, between the pereiopods and on the pleopods. They are native to Australasia and South America, although Iais californica and its host Sphaeroma quoyanum have invaded California, and I. californica was first described from Sausalito, California. Nine species are recognised:
Idotea is a genus of isopod crustaceans, mostly from cold temperate waters. The taxonomy of the genus is still in doubt, and many of the currently recognised species may be taxonomic synonyms, and others may be moved to different genera.
The Cirolanidae are a family of isopod crustaceans, including these genera:
Remasellus parvus, the swimming Florida cave isopod, is an isopod endemic to 4 caves in the Ochlockonee and Aucilla-Suwanee drainages of Florida, United States. It is the only species in the genus Remasellus.
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.
Cymothoa is a genus of parasitic isopod crustaceans, containing the species listed below. Not all Cymothoa species are considered parasitic. Some climb onto fish in an act known as phoresy.
Hemioniscus balani, a species of isopod crustacean, is a widespread parasitic castrator of barnacle in the northern Atlantic Ocean. Its range extends from Norway to the Atlantic coast of France, and as far west as Massachusetts. It is also commonly found on the Pacific coast of North America; it is not known if the Pacific and Atlantic populations are the same species, or if the Pacific population exists following human-assisted introduction.
The Aegidae are a family of isopod crustaceans. The adults are temporary parasites of fish, feeding on their hosts' blood before dropping off to digest the meal. They differ from members of the family Cirolanidae in having only three pairs of hook-like pereiopods, whereas in Cirolanidae all seven pairs of pereiopods are hooked. The family was first described by Adam White in 1850.
Ligia baudiniana is a woodlouse in the family Ligiidae. It has a coarsely granular surface and large eyes that are very close together.
Exosphaeroma is a genus of marine isopod of the family Sphaeromatidae. This genus is found in shallow ocean waters worldwide. It is notable for being one of the few genera of sphaeromatid to be found in the southern reaches of the Southern Ocean. The greatest diversity of Exosphaeroma occurs in the Southern Hemisphere.
Aega is a genus of isopods in the family Aegidae, containing the following species:
Nerocila is a genus of parasitic isopod crustaceans, with 11 species, which have been found parasitizing Indian marine fishes.
Ceratothoais a genus of isopod ectoparasites of teleost fish, first described by James Dwight Dana in 1852. Infection by Ceratothoa can cause anaemia, lesions, growth retardation, emaciation, and mortality in their fish hosts.
Euidotea is a genus of marine isopods belonging to the family Idoteidae. The species of this genus are found in Australia and New Zealand.
Rocinela is a genus of isopods in the family Aegidae, and was first described in 1818 by William Elford Leach. The type species is Rocinela danmoniensis Leach, 1818.
