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. Although some doubt still exists about this hypothesis, king crabs are the most widely quoted 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.
Petrolisthes elongatus, known as the New Zealand half crab, elongated porcelain crab, blue half crab, blue false crab or simply as the half crab or false crab, is a species of porcelain crab native to New Zealand.
Paralomis is a genus of king crabs. They are found in the cold waters of a depth range of 950 m (3,120 ft) to 1,000 m (3,300 ft). with the deepest depth range is 7,783 m (25,535 ft).
Neolithodes is a genus of king crabs, in the family Lithodidae. They are found in all major oceans, both in high and low latitudes. Although there are records from water as shallow as 124 m (407 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.
Oregonia bifurca, commonly known as the split-nose crab or the split-nose decorator crab, is a species of crabs belonging to the family Oregoniidae. It is a rare deep-water species that inhabits the tops of seamounts and guyots in the northeastern Pacific Ocean; from the Aleutian Islands, the Bering Sea, the Hawaiian–Emperor seamount chain, to the waters off British Columbia. It is closely related to the more common shallow-water species Oregonia gracilis, the graceful decorator crab.
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.
Neolithodes flindersi is a species of king crab found in southeastern Australia. They have been found at depths of 887–1,333 metres (2,910–4,373 ft) but typically appear from 950–1,050 metres (3,120–3,440 ft). They most closely resemble Neolithodes brodiei and Neolithodes nipponensis.
Neolithodes agassizii is a species of king crab native to the Western Atlantic. They live at depths of 200–1,900 metres (660–6,230 ft), and have been found as far south as Rio de Janeiro, as far north as latitude 36°, and near the Equator. It has been found in the southwestern Caribbean Sea as well as the Gulf of Mexico.
Neolithodes yaldwyni is a species of king crab which is found in the Ross Sea from depths of 124–1,950 metres (407–6,398 ft). It had previously been misidentified as Neolithodes brodiei, and it closely resembles Neolithodes capensis.
Neolithodes bronwynae, commonly known as the rock crab, is a species of king crab which is found at the Whakatane Seamount in the Bay of Plenty, the Lord Howe Rise near Lord Howe Island, eastern Australia, and possibly New Caledonia. It has been found at depths of 1,515–2,643 metres (4,970–8,671 ft).
Neolithodes brodiei, also known as Brodie's king crab, is a species of king crab which is native to New Zealand and its adjacent waters. It lives at a depth of 500–1,240 metres (1,640–4,070 ft) but is typically found within a depth of 950–1,150 metres (3,120–3,770 ft). It is the most widespread and common lithodid in New Zealand waters, and the New Zealand Department of Conservation classifies it as "Not Threatened".
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".
Neolithodes indicus is a species of king crab found in the southeastern Arabian Sea.
Lithodes jessica is a species of king crab in the genus Lithodes. It is found off the coast of New Zealand on the Lord Howe Rise at depths from 680–1,100 m (2,230–3,610 ft).
Lithodes macquariae is a species of king crab located off Macquarie Island, the Auckland Islands, and Peter I Island. It has been found at depths of 16–1,140 m (52–3,740 ft).
Lithodes turkayi is a species of king crab. It has been found at depths of 70–1,696 m (230–5,564 ft) and lives in the Pacific Ocean off the coast of Chile, the southern Atlantic Ocean near the Falkland Islands, and the Southern Ocean in the Bellingshausen Sea.
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).
Lithodes robertsoni is a species of king crab. It has been found in New Zealand at depths between 935–1,259 m (3,068–4,131 ft). It is distributed from as far north as the Challenger Plateau to as far south as the Snares Islands. The largest yet-examined specimen is its male holotype whose carapace measures 128.1 mm (5.04 in) in postrostral length and 117.0 mm (4.61 in) in width.
