The Caridea, commonly known as caridean shrimp or true shrimp, from the Greek word καρίς, καρίδος, are an infraorder of shrimp within the order Decapoda. This infraorder contains all species of true shrimp. They are found widely around the world in both fresh and salt water. Many other animals with similar names – such as the mud shrimp of Axiidea and the boxer shrimp of Stenopodidea – are not true shrimp, but many have evolved features similar to true shrimp.
King crabs are decapod crustaceans of the family Lithodidae that are chiefly found in deep waters and are adapted to cold environments. They are composed of two subfamilies: Lithodinae, which tend to inhabit deep waters, are globally distributed, and comprise the majority of the family's species diversity; and Hapalogastrinae, which are endemic to the North Pacific and inhabit exclusively shallow waters. King crabs superficially resemble true crabs but are generally understood to be closest to the pagurid hermit crabs. This placement of king crabs among the hermit crabs is supported by several anatomical peculiarities which are present only in king crabs and hermit crabs, making them a prominent example of carcinisation among decapods. Several species of king crabs, especially in Alaskan and southern South American waters, are targeted by commercial fisheries and have been subject to overfishing.
Anomura is a group of decapod crustaceans, including hermit crabs and others. Although the names of many anomurans include the word crab, all true crabs are in the sister group to the Anomura, the Brachyura.
Ocypode is a genus of ghost crabs found in the sandy shores of tropical and subtropical regions throughout the world. They have a box-like body, thick and elongated eyestalks, and one claw is larger than the other in both males and females. They inhabit deep burrows in the intertidal zone. They are primarily nocturnal, and are generalist scavengers and predators of small animals. The genus contains 21 species.
The graceful rock crab or slender crab, Metacarcinus gracilis or Cancer gracilis, is one of two members of the genus Metacarcinus, with white tipped chelae (claws). The second crab in the genus to have white tipped claws is M. magister. Both of these eastern Pacific crab species are recognized by ITIS as belonging to the much larger genus Cancer. M. gracilis has been caught from Alaska to Bahía Magdelena, Baja California. Although M. gracilis is only found in the Pacific Ocean, it has cousins in the Atlantic Ocean. The genus Cancer apparently evolved in the Pacific Ocean and later migrated to the Atlantic Ocean. Larvae and small juveniles of this species are often seen riding jellyfish, especially Phacellophora camtschatica. The juvenile crabs steal food from the jellyfish and also clean off parasitic amphipods.
Rhinolithodes wosnessenskii, also called the rhinoceros crab, is a species of king crab, the only species in the genus Rhinolithodes. The species is named after Ilya Gavrilovich Voznesenski. It is found at depths of 6–73 metres (20–240 ft) in the north-east Pacific Ocean from Kodiak, Alaska to Crescent City, California.
Paralomis is a widely distributed, highly speciose, and morphologically diverse genus of king crabs in the subfamily Lithodinae.
Neolithodes is a genus of king crabs in the subfamily Lithodinae. They are found in all major oceans, both in high and low latitudes. Although there are records from water as shallow as 70 m (230 ft) in cold regions, most records are much deeper, typically 700–2,000 m (2,300–6,600 ft), with the deepest confirmed at 5,238 m (17,185 ft). They are fairly large to large crabs that typically are reddish in color and spiny, although the size of these spines varies depending on species.
Cryptolithodes typicus, often referred to as the butterfly crab or the turtle crab, is a species of lithodid crustacean native to coastal regions of the northeastern Pacific Ocean, ranging from Amchitka Island, Alaska to Santa Rosa Island, California.
Oregonia is a genus of crabs, comprising two extant species and one fossil species: It is classified in the family Oregoniidae under the spider crab superfamily Majoidea.
Calappa japonica, also known as the Japanese shame-faced crab, is a marine species of box crab in the family Calappidae. Originally found in the waters around Japan, more recently it has been found in Africa, the Red Sea and Western Australia.
Cyclocoeloma is a genus of crabs in the family Majidae, containing the single species Cyclocoeloma tuberculata.
Neosarmatium smithi, is a swimming crab species in the genus Neosarmatium. Distributed all over marine and brackish waters of Indo-West Pacific regions.
Paralomis zealandica, also known as the prickly king crab, is a species of king crab which lives at a depth between 254–1,212 m (833–3,976 ft) in New Zealand. It has a spiky carapace.
Acanthosquilla derijardi is a species of stomatopod crustacean. Its distribution is widespread throughout the Indo-West Pacific. The species was initially described by the American carcinologist Raymond B. Manning in 1970. Its junior synonym, A. sirindhorn, was named in 1995 in honor of Princess Sirindhorn of Thailand.
Neolithodes capensis is a species of king crab which is found in the Southern Ocean and the western Indian Ocean. It has been found to a depth of 660–3,200 metres (2,170–10,500 ft). They have been found near Cape Point and around the Crozet and Kerguelen Islands in the subantarctic, and they are widespread in the Bellingshausen Sea on the Antarctic continental slope.
Neolithodes nipponensis is a species of king crab which is found in Japan and Taiwan. It has been found at depths from 200–1,752 metres (656–5,748 ft).
Paralomis dawsoni is a species of king crab which lives in New Caledonia, northern New Zealand, and the Solomon Islands at depths of 400–1,118 m (1,312–3,668 ft). Alongside P. zealandica, it is one of the two most common species of Paralomis in New Zealand. As of 2023, the Department of Conservation in New Zealand classifies P. dawsoni as "Naturally Uncommon".
Paralomis okitoriensis is a species of king crab. It has been identified near Japan's southernmost atoll, Okinotorishima.
Lithodes australiensis is a species of king crab. They live in southeastern Australia, known as far north as Cape Hawke and as far south as the South Tasman Rise. They have been found at depths between 540–1,312 m (1,772–4,304 ft), but they typically live between 1,000–1,100 m (3,300–3,600 ft).
