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.
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:
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.
Gnathia is a genus of isopod crustaceans, containing the following species:
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.
The Crinoniscidae are a family of isopod crustaceans in the suborder Cymothoida. The original description was made by Bonnier in 1900. Members of this family are parasites, mostly on other crustaceans. Crinoniscus equitans is parasitic on the barnacle, Balanus perforatus.
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 Hemioniscidae 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 cirripede barnacles.
The Podasconidae are a family of marine isopod crustaceans in the suborder Cymothoida. The original description was made by Giard and Bonnier in 1895. Members of this family are parasitic on amphipods.
Asconiscus is a genus in the Asconiscidae family of marine isopod crustaceans in the suborder Cymothoida, containing a single genus and a single species, Asconiscus simplex. The original description of the family was made by Bonnier in 1900. A. simplex is a parasite of the shrimp-like crustacean, Boreomysis arctica.
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:
The Entoniscidae are a family of marine isopod crustaceans in the suborder Cymothoida. Members of this family are parasites of brachyuran and anomuran crabs, living in their hosts' haemocoel. A small chitinised hole develops through the host's exoskeleton through which the isopod can communicate with the environment. The female isopod bears little resemblance to any free-living isopod, but the morphology of the larvae show their taxonomic affiliations.
Serolidae is a family of isopod crustaceans, containing the following genera :
The Arcturidae are a family of marine isopod crustaceans in the suborder Valvifera. Members of the family resemble woodlice and are found globally in cooler areas in shallow seas.
The Munnidae are a family of isopod crustaceans, containing these genera:
Janiridae is a family of isopods in the order Isopoda. There are more than 20 genera and 190 described species in Janiridae.
Anuropus is a genus of isopods in the suborder Cymothoida. As of 2021, it is the only genus in the family Anuropidae.
Antarcturidae is a family of marine isopods belonging to the suborder Valvifera.
Nannoniscus is genus of crustaceans.
