King crabs are decapod crustaceans in the family Lithodidae that are chiefly found in deep waters. King crabs are not true crabs and are generally thought to be derived from hermit crab ancestors within the Paguridae, which may explain the asymmetry still found in the adult forms. This ancestry is supported by several anatomical peculiarities which are present only in king crabs and hermit crabs. Although some doubt still exists about this hypothesis, king crabs are the most widely quoted example of carcinisation among the Decapoda. Several species of king crabs, especially in Alaskan and southern South American waters, are targeted by commercial fisheries and have been subject to overfishing.
Cancer is a genus of marine crabs in the family Cancridae. It includes eight extant species and three extinct species, including familiar crabs of the littoral zone, such as the European edible crab, the Jonah crab and the red rock crab. It is thought to have evolved from related genera in the Pacific Ocean in the Miocene.
Mictyris is a genus of brightly coloured crabs, placed in its own taxonomical family, the Mictyridae. It inhabits the central Indo-West Pacific region. These crabs congregate on mud flats or beaches in groups of a few thousand, and filter sand or mud for microscopic organisms. They congregate during low tide, and bury themselves in the sand during high tide or whenever they are threatened. This is done in wet sand, and they dig in a corkscrew pattern, leaving many small round pellets of sand behind them.
Kiwa is a genus of marine decapods living at deep-sea hydrothermal vents and cold seeps. The animals are commonly referred to as "yeti lobsters" or "yeti crabs”, after the legendary yeti, because of their "hairy" or bristly appearance. The genus is placed in its own family, Kiwaidae, in the superfamily Chirostyloidea. The genus Kiwa is named after the god of shellfish in Polynesian mythology.
The Bythograeidae are a small family of blind crabs which live around hydrothermal vents. The family contains 16 species in six genera. Their relationships to other crabs are unclear. They are believed to eat bacteria and other vent organisms. Bythograeidae are a monophyletic, sister taxon of the superfamily Xanthoidea which split to inhabit hydrothermal vents around the Eocene.
Discoplax is a genus of terrestrial crabs. It is very closely related to the genus Cardisoma.
Discoplax longipes is a species of terrestrial crab. It is found in karstic caves on Pacific islands and ranges from the Loyalty Islands to French Polynesia. Mating occurs in the caves, after which the females migrate to the sea to release their fertilised eggs. The genus Discoplax was for a long time synonymised with Cardisoma, but was resurrected in the late 20th century.
Pseudothelphusidae is a family of freshwater crabs found chiefly in mountain streams in the Neotropics. They are believed to have originated in the Greater Antilles and then crossed to Central America via a Pliocene land bridge. Some species of this family are troglobitic.
Johngarthia is a genus of crabs in the land crab family Gecarcinidae, formerly included in the genus Gecarcinus, and containing six species. The genus bears the name of John S. Garth, a 20th century naturalist who specialized in crabs and other arthropods.
Vultocinus anfractus is a species of crab, the only species in the family Vultocinidae. It has been found around the Philippines, Vanuatu and New Caledonia, and lives on driftwood. Its discovery forced a reappraisal of the relationships within the superfamily Goneplacoidea, and to the recognition of Mathildellidae, Conleyidae and Progeryonidae as separate families.
Karstarma is a genus of karst-dwelling crabs formerly included in Sesarmoides.
Gandalfus yunohana is a species of blind crab in the family Bythograeidae found on hydrothermal vents on the eastern edge of the Philippine Sea Plate south of Japan. Because no light penetrates to such depths, the eyes of G. yunohana are immobile and unpigmented.
Euryxanthops is a genus of crabs in the family Xanthidae. It was originally established in 1983 by Garth & Kim to contain three species of deep-water crabs from Japan and the Philippines - Euryxanthops dorsiconvexus, Euryxanthops flexidentatus and Euryxanthops orientalis. Since then, several more species of this genus have been identified and described, and Euryxanthops currently contains:
Danièle Guinot is a French biologist, an emeritus professor at the Muséum national d'histoire naturelle in France, known for her research on crabs.
Colin McLay (1942-2022) was a New Zealand marine biologist and carcinologist. Educated at the University of Otago and the University of British Columbia, he served as an Associate Professor of Marine Biology at the University of Canterbury. He discovered several species of crab, including Desmodromia tranterae, Euryxanthops chiltoni, Gandalfus puia, and Hirsutodynomene vespertilio.
Gandalfus puia is the only known New Zealand species of crab in the family Bythograeidae, commonly known as the blind vent crabs. Like other blind vent crabs, it only lives in hydrothermal vent waters. This species was first described in 2007 after specimens were collected from the undersea volcanic ridge near the Kermadec Islands.
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.
Gandalfus is a genus of crabs belonging to the family Bythograeidae. Gandalfus species occur around hydrothermal vents.
Eifuku and NW Eifuku (北西永福) are two seamounts in the Pacific Ocean. The better known one is NW Eifuku, where an unusual hydrothermal vent called "Champagne" produced droplets of liquid CO
2. Both seamounts are located in the Northern Marianas and are volcanoes, part of the Izu-Bonin-Mariana Arc. NW Eifuku rises to 1,535 metres (5,036 ft) depth below sea level and is a 9 kilometres (5.6 mi) wide volcanic cone.
Tubuca dussumieri, is a species of fiddler crab that is found in the western and south pacific including New Caledonia, Indonesia, Malaysia, Taiwan, Japan, north eastern Australia
