King crabs are a superfamily of crab-like decapod crustaceans chiefly found in cold seas. Because of their large size and the taste of their meat, many species are widely caught and sold as food, the most common being the red king crab, Paralithodes camtschaticus.

King crabs are generally thought to be derived from hermit crab-like ancestors, 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 theory, king crabs are the most widely quoted example of carcinisation among the Decapoda. The evidence for this explanation comes from the asymmetry of the king crab's abdomen, which is thought to reflect the asymmetry of hermit crabs, which must fit into a spiral shell. Although formerly classified among the hermit crabs in the superfamily Paguroidea, king crabs are now placed in a separate superfamily, Lithodoidea. This is not without controversy as there is a widespread consensus in the scientific community that king crabs are derived from hermit crabs and closely related to pagurid hermit crabs, and therefore a separate superfamily in the classification poorly reflects the phylogenetic relationship of this taxon.

Species



Lithodes longispina
Around 121 species are known, in 10 genera:

Cryptolithodes Brandt, 1848
Cryptolithodes expansus Miers, 1879
Cryptolithodes sitchensis Brandt, 1853 – umbrella crab
Cryptolithodes typicus Brandt, 1848 – butterfly crab
Glyptolithodes Faxon, 1895
Glyptolithodes cristatipes (Faxon, 1893)
Lithodes Latreille, 1806
Lithodes aequispinus J. E. Benedict, 1895 – golden king crab
Lithodes aotearoa Ahyong, 2010
Lithodes australiensis Ahyong, 2010
Lithodes ceramensis Takeda & Nagai, 2004
Lithodes chaddertoni Ahyong, 2010
Lithodes confundens Macpherson, 1988
Lithodes couesi J. E. Benedict, 1895 – scarlet king crab
Lithodes ferox Filhol, 1885
Lithodes formosae Ahyong & Chan, 2010
Lithodes galapagensis Hall & Thatje, 2009
Lithodes jessica Ahyong, 2010
Lithodes longispina Sakai, 1971
Lithodes macquariae Ahyong, 2010
Lithodes maja (Linnaeus, 1758) – Norway king crab
Lithodes mamillifer Macpherson, 1988d
Lithodes mandtii
Lithodes manningi Macpherson, 1988
Lithodes megacantha Macpherson, 1991
Lithodes murrayi Henderson, 1888
Lithodes nintokuae Sakai, 1976
Lithodes panamensis Faxon, 1893
Lithodes paulayi Macpherson & Chan, 2008
Lithodes rachelae Ahyong, 2010
Lithodes richeri Macpherson, 1990
Lithodes robertsoni Ahyong, 2010
Lithodes santolla (Molina, 1782) – Chilean centolla or Chilean king crab
Lithodes turkayi Macpherson, 1988
Lithodes turritus Ortmann, 1892
Lithodes unicornis Macpherson, 1984
Lithodes wiracocha Haig, 1974
Lopholithodes Brandt, 1848
Lopholithodes foraminatus (Stimpson, 1859) – brown box crab
Lopholithodes mandtii Brandt, 1848 – Puget Sound king crab
Neolithodes A. Milne-Edwards & Bouvier, 1894
Neolithodes agassizii (S. I. Smith, 1882)
Neolithodes asperrimus Barnard, 1947
Neolithodes brodiei Dawson & Yaldwyn, 1970
Neolithodes bronwynae Ahyong, 2010
Neolithodes capensis Stebbing, 1905
Neolithodes diomedeae (J. E. Benedict, 1895)
Neolithodes duhameli Macpherson, 2004
Neolithodes flindersi Ahyong, 2010
Neolithodes grimaldii (A. Milne-Edwards & Bouvier, 1894)
Neolithodes nipponensis Sakai, 1971
Neolithodes vinogradovi Macpherson, 1988
Neolithodes yaldwyni Ahyong & Dawson, 2006
Paralithodes Brandt, 1848
Paralithodes brevipes (H. Milne Edwards & Lucas, 1841)
Paralithodes californiensis (J. E. Benedict, 1895) – California king crab
Paralithodes camtschaticus (Tilesius, 1815) – red king crab
Paralithodes platypus Brandt, 1850 – blue king crab
Paralithodes rathbuni (J. E. Benedict, 1895)
Paralomis White, 1856
Paralomis aculeata Henderson, 1888
Paralomis africana Macpherson, 1982
Paralomis alcockiana Hall & Thatje, 2009
Paralomis anamerae Macpherson, 1988
Paralomis arae Macpherson, 2001
Paralomis arethusa Macpherson, 1994
Paralomis aspera Faxon, 1893
Paralomis birsteini Macpherson, 1988
Paralomis bouvieri Hansen, 1908
Paralomis ceres Macpherson, 1989
Paralomis chilensis Andrade, 1980
Paralomis cristata Takeda & Ohta, 1979
Paralomis cristulata Macpherson, 1988
Paralomis cubensis Chace, 1939
Paralomis danida Takeda & Bussarawit, 2007
Paralomis dawsoni Macpherson, 2001
Paralomis diomedeae (Faxon, 1893)
Paralomis dofleini Balss, 1911
Paralomis echidna Ahyong, 2010
Paralomis elongata Spiridonov, Türkay, Arntz & Thatje, 2006
Paralomis erinacea Macpherson, 1988
Paralomis formosa Henderson, 1888
Paralomis gowlettholmes Ahyong, 2010
Paralomis granulosa (Hombron & Jacquinot, 1846)
Paralomis grossmani Macpherson, 1988
Paralomis haigae Eldredge, 1976
Paralomis hirtella de Saint Laurent & Macpherson, 1997
Paralomis histrix (De Haan, 1849)
Paralomis hystrixoides Sakai, 1980
Paralomis inca Haig, 1974
Paralomis indica Alcock & Anderson, 1899
Paralomis investigatoris Alcock & Anderson, 1899
Paralomis jamsteci Takeda & Hashimoto, 1990
Paralomis japonicus Balss, 1911
Paralomis kyushupalauensis Takeda, 1985
Paralomis longidactylus Birstein & Vinogradov, 1972
Paralomis longipes Faxon, 1893
Paralomis makarovi Hall & Thatje, 2009
Paralomis manningi Williams, Smith & Baco, 2000
Paralomis medipacifica Takeda, 1974
Paralomis mendagnai Macpherson, 2003
Paralomis microps Filhol, 1884
Paralomis multispina (Benedict, 1895)
Paralomis nivosa Hall & Thatje, 2009
Paralomis ochthodes Macpherson, 1988
Paralomis odawarai (Sakai, 1980)
Paralomis otsuae Wilson, 1990
Paralomis pacifica Sakai, 1978
Paralomis papillata (Benedict, 1895)
Paralomis pectinata Macpherson, 1988
Paralomis phrixa Macpherson, 1992
Paralomis poorei Ahyong, 2010
Paralomis roeleveldae Kensley, 1981
Paralomis seagranti Eldredge, 1976
Paralomis serrata Macpherson, 1988
Paralomis spectabilis Hansen, 1908
Paralomis spinosissima Birstein & Vinogradov, 1972
Paralomis staplesi Ahyong, 2010
Paralomis stella Macpherson, 1988
Paralomis stevensi Ahyong & Dawson, 2006
Paralomis taylorae Ahyong, 2010
Paralomis truncatispinosa Takeda & Miyake, 1980
Paralomis tuberipes Macpherson, 1988
Paralomis verrilli (Benedict, 1895)
Paralomis webberi Ahyong, 2010
Paralomis zealandica Dawson & Yaldwyn, 1971
Phyllolithodes Brandt, 1848
Phyllolithodes papillosus Brandt, 1848 – flatspine triangle crab, heart crab
Rhinolithodes Brandt, 1848
Rhinolithodes wosnessenskii Brandt, 1848 – rhinoceros crab

Sculptolithodes Makarov, 1934
Sculptolithodes derjugini Makarov, 1934
Main article: Glyptolithodes
Glyptolithodes is found chiefly in the Southern Hemisphere, but extending as far north as California, although all its closest relatives live in the Northern Hemisphere. Its single species, G. cristatipes was originally placed in the genus Rhinolithodes.

In 2011, scientists found Neolithodes yaldwini on the edge of Antarctica, probably as a result of global warming, with major impacts on sediment texture, bioturbation and local faunal diversity.

Red (P. camtschaticus) and blue (P. platypus) king crabs are some of the most important fisheries in Alaska, however populations have fluctuated in the past 25 years and some areas are currently closed due to overfishing. The two species are similar in size, shape and life history. Habitat is the main factor separating the range of blue and red king crabs in the Bering Sea. Red king crabs prefer shallow, muddy or sandy habitats in Bristol Bay and Norton Sound, while blue king crabs prefer the deeper areas made up of cobble, gravel and rock that occur around the Pribilof, St. Matthew, St. Lawrence and the Diomede Islands.

Red king crabs have an 11-month brood cycle in their first reproductive year and a 12-month cycle thereafter. Both red and blue king crabs have planktotrophic larvae that undergo 4 zoeal stages in the water column and a non-feeding, glaucothoe stage which is an intermediate stage which seeks appropriate habitat on the sea floor.


Red king crabs make up over 90% of the annual king crab harvest. This crab is in the collection of the Children's Museum of Indianapolis.
Main article: Paralithodes camtschaticus
The red king crab, Paralithodes camtschaticus, is a very large species, sometimes reaching a carapace width of 11 in (28 cm) and a leg span of 6 ft (1.8 m). Its natural range is the Bering Sea around the Kamchatka Peninsula area, between the Aleutian Islands and St. Lawrence Island. It can now also be found in the Barents Sea and the European Arctic, where it was intentionally introduced and is now becoming a pest.

Main article: Paralithodes platypus
The blue king crab, Paralithodes platypus, lives near St. Matthew Island, the Pribilof Islands, and the Diomede Islands, Alaska, and there are populations along the coasts of Japan and Russia. Blue king crabs from the Pribilof Islands are the largest of all the king crabs, sometimes exceeding 18 lb (8 kg) in weight.



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