Thompsonia is a genus of barnacles which has evolved into an endoparasite of other crustaceans, including crabs and snapping shrimp. It spreads through the host's body as a network of threads, and produces many egg capsules which emerge through joints in the host's shell.
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.
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:
Serolis is a genus of isopod crustacean, containing the following 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:
The Idoteidae are a family of isopod crustaceans. It includes these genera:
The Microcerberidea are a suborder of isopod crustaceans. They are less than 2 mm (0.079 in) long, and live interstitially. They may be found in the eastern Pacific Ocean, and around the coasts of South America, Africa, the Mediterranean Sea, and India.
Phreatoicidae is a family of blind, freshwater isopods. They have survived apparently unchanged for 350 million years, and are only found in South Africa, India, Australia and New Zealand. They were first found near Christchurch in 1882 by Charles Chilton. The family Phreatoicidae now contains 13 genera:
The Leptanthuridae are a family of isopod crustaceans, containing the following genera:
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.
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 Bopyridae are a family of isopod crustaceans in the suborder Cymothoida. There are 1223 individual species contained in this family. Members of the family are ectoparasites of crabs and shrimp. They live in the gill cavities or under the carapace where they cause a noticeable swelling. Fossil crustaceans have occasionally been observed to have a similar characteristic bulge.
Cancricepon is a genus of isopod crustaceans in the family Bopyridae. It has been synonymised with Merocepon Richardson, 1910.
Chiridotea is a genus of isopod crustaceans in the family Chaetiliidae, containing the following species:
The Chaetiliidae are a family of isopod crustaceans in the suborder Valvifera, comprising these genera:
Saduria is a genus of benthic isopod crustaceans in the family Chaetiliidae, containing the following species:
The Cabiropidae are a family of isopod crustaceans in the suborder Cymothoida. The original description was made by Giard and Bonnier in 1887. Members of the family are hyperparasites of other parasitic isopods in the order and some are parasites on other free-living isopods.
The Cyproniscidae are a family of marine isopod crustaceans in the suborder Cymothoida. The original description was made by Bonnier in 1900. Members of this family are parasitic on other isopods.
The Dajidae are a family of marine isopod crustaceans in the suborder Cymothoida. The original description was made by Giard and Bonnier in 1887. Members of this family are ectoparasites of krill. They resemble a fleshy growth on the krill's back, and make the host look as if it is wearing a rucksack. These genera are included in the family Dajidae:
