Hymenosomatidae is a family of crabs with some 110 described species in nearly 20 genera. The following genera are placed in the Hymenosomatidae:
Tuerkayana hirtipes is a species of terrestrial crab.
Discoplax is a genus of terrestrial crabs. It is very closely related to the genus Cardisoma.
Cardisoma is a genus of large land crabs. Three species formerly placed in this genus are now placed in Discoplax. The four species that remain in Cardisoma are found in warm coastal regions where they live in burrows. Young individuals are often very colourful with a purple-blue carapace and orange-red legs, but as they grow older the colours tend to fade, and females may be duller than males. Although less extreme than in fiddler crabs, one claw is usually considerably larger than the other. They are omnivores, but primarily feed on plant material.
Hainanpotamon vietnamicum is a species of crab. Originally described as a species of Geothelphusa, it is now treated as part of the genus Hainanpotamon, although it has also been suggested as a member of Tiwaripotamon. It is only known from a single locality in Cúc Phương National Park, Ninh Bình Province, Vietnam.
Pseudozioidea is a superfamily of crabs, formerly treated in the Eriphioidea, Carpilioidea, Xanthoidea, Pilumnoidea and Goneplacoidea. A number of fossils from the Eocene onwards are known from the family Pseudoziidae. Eleven genera are recognised in three families:
Johora singaporensis, the Singapore stream crab or Singapore freshwater crab, is a critically endangered species of freshwater crab endemic to Singapore. It grows to a size of 30 millimetres (1.2 in) wide.
Amarinus lacustris is a species of freshwater crab from Australia, New Zealand and nearby islands, where it lives in water of various salinities. It grows up to 10 mm (0.4 in) wide, with an H-shaped groove on its back. It is an omnivore and is eaten by crayfish and fish. It was first discovered in Lake Pupuke, near Auckland, and is the only freshwater crab in New Zealand.
Neoepilobocera gertraudae is a species of cave-dwelling crab from Cuba.
Villalobosius is a genus of crabs in the family Pseudothelphusidae, containing a single species, Villalobosius lopezformenti. It lives in the northern part of the state of Oaxaca, Mexico, on the Isthmus of Tehuantepec, and is adapted to a troglobitic lifestyle.
Karstarma is a genus of karst-dwelling crabs formerly included in Sesarmoides.
Hainanpotamon is a genus of freshwater crabs, containing the following species:
Cancrocaeca xenomorpha is a species of troglobitic (cave-dwelling) freshwater crab from Sulawesi, the only species in the monotypic genus Cancrocaeca. It has been described as the world's "most highly cave-adapted species of crab".
Geosesarma dennerle is a species of small land-living crabs found on Java, Indonesia.
Christmaplax mirabilis is a species of crab native to Christmas Island, Australia. It is the only known species in the genus Christmaplax.
Nanhaipotamon is a genus of freshwater crabs, in the subfamily Potamiscinae, found in southern China and Taiwan. As of 2018, 18 species have been described. The genus is named after the South China Sea, for it occurs mostly in coastal areas. The genus was first described by R. Bott in 1968 as Isolapotamon (Nanhaipotamon), i.e., a subgenus of Isolapotamon.
Leptuca deichmanni, commonly known as Deichmann's fiddler crab, is a species of fiddler crab native to the eastern Pacific coast of Central America, in Costa Rica and Panama.
Leptuca musica, commonly known as the musical fiddler crab, is a species of fiddler crab native to Baja California and the Gulf of California in Mexico.
Leptuca terpsichores, commonly known as the dancing fiddler crab, is a species of fiddler crab native to the eastern Pacific coast of the Americas, from Nicaragua to Peru.
Limnopilos is a genus of small hymenosomatid crabs endemic to Southeast Asia. The genus was described by Christina Chuang and Peter Ng in 1991, who identified the new species Limnopilos naiyanetri and distinguished it from the closely related genus Hymenicoides. Its true taxonomic classification was debated for several years, but in 2007 the discovery of a new species of crab in this genus solidified the distinction between Limnopilos and Hymenicoides. Many aspects of the genus Limnopilos are still poorly understood. Their ecology and natural history have not been studied in detail, and their reproductive cycle remains mysterious.
