Paralithodes camtschaticus (red king crab)
- Summary of Invasiveness
- Taxonomic Tree
- Notes on Taxonomy and Nomenclature
- Distribution Table
- History of Introduction and Spread
- Risk of Introduction
- Habitat List
- Biology and Ecology
- Water Tolerances
- Notes on Natural Enemies
- Means of Movement and Dispersal
- Impact Summary
- Economic Impact
- Environmental Impact
- Risk and Impact Factors
- Detection and Inspection
- Similarities to Other Species/Conditions
- Prevention and Control
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Paralithodes camtschaticus (Tilesius, 1815)
Preferred Common Name
- red king crab
Other Scientific Names
- Maja camtschatica Tilesius, 1815
- Paralithodes camtschatica
International Common Names
- English: Alaska king crab
- Russian: Kamtschatca crab
Local Common Names
- Germany: Königskrabbe
- Netherlands: rode koningskrab
- Norway: kongekrabbe
Summary of InvasivenessTop of page
The red king crab, P. camtschaticus, is native to the Okhotsk and Japan seas, the Bering Sea and the northern Pacific Ocean. In the 1960s it was intentionally released by Russian scientists into the Barents Sea to create a new fishing resource.
P. camtschaticus is a generalist predator and may impact native biodiversity and exploit commercial scallop beds. Its carapace is a favoured substrate for the leech Johanssonia arctica to deposit its eggs; the leech is a vector for a trypanosome blood parasite of marine fish, including cod. Research suggests red king crabs are indirectly responsible for increased transmission of trypanosomes to cod by promoting an increase in the populations of the leech vector (Hemmingsen et al., 2005).
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Metazoa
- Phylum: Arthropoda
- Subphylum: Crustacea
- Class: Malacostraca
- Subclass: Eumalacostraca
- Order: Decapoda
- Suborder: Reptantia
- Unknown: Paguroidea
- Family: Lithodidae
- Genus: Paralithodes
- Species: Paralithodes camtschaticus
Notes on Taxonomy and NomenclatureTop of page
The king crabs were originally described by Tilesius (1815) as a member of the genus Maja, family Majidae. Latreille (1829) recognized that king crabs were not brachyurans but rather anomurans, and consequently transferred king crabs to the genus Lithodes. Bouvier (1896) split the genus Lithodes primarily on the basis of the different pattern of calcification of the plates of the second abdominal segment of the abdomen, and erected the genus Paralithodes for those forms with five distinct plates separated by well defined sutures (Bright, 1967).
DescriptionTop of page
P. camtschaticus, which is among the world’s largest arthropods (weighing over 10 kg and 22 cm in carapace length) (Powell and Nickerson, 1965) has a crab-like morphology and a strong calcified exoskeleton with spines (Cunningham et al., 1992). It has a fused head and thorax, a fan shaped tail, 5 sets of appendages, the first two are pincers, the right is usually larger than the left, and three pairs of walking legs. In the front, the crab has an array of antennae and mouth parts (mandibles, maxillae and maxillipeds). The body is red/brownish although blue forms are also found.
Settlement of larvae in shallow waters <20 m) usually takes place on sponges, bryozoans and macroalgae (Marukawa, 1933). Red king crabs smaller than 20 mm carapace length (CL) have no podding behaviour and remain solitary the first year living cryptically beneath rocks and stones and in crevices. In the second year (20-25 mm CL) podding behaviours are seen (Dew, 1990). After the first two years they migrate to deeper water (20-50 m depth) where they congregate in large, tightly packed groups, often referred to as pods (Powell, 1974).
DistributionTop of page
P. camtschaticus is native to the Okhotsk and Japan seas, the Bering Sea and the northern Pacific Ocean. On the Asian side of the Pacific, crabs are found from Korea, along the eastern coast of Siberia and the coasts of the Kamchatka Peninsula. In the northeast Pacific and Bering Sea the red king crab is distributed throughout the Aleutian Island chain, north to Norton Sound, Alaska, and southeast to Great Bay in Vancouver Island, Canada.
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Atlantic, Northeast||Present||Introduced||1961||Not invasive||Orlov and Ivanov, 1978||Barents Sea: Kolafjord, spread to Kanin/Goose Bank and from Kolafjord into the Norwegian zone|
|Norway||Present||Introduced||1992||Invasive||Hjelset et al., 2009||First recorded in are 27 in 1992 (Varanger Fjord)|
|Russian Federation||Present||Present based on regional distribution.|
|-Northern Russia||Present||Introduced||1961||Not invasive||Orlov and Ivanov, 1978||First recorded in area 27 in 1978 (Coast of Kola)|
History of Introduction and SpreadTop of page
During the period from 1961 to 1969, 1.5 million zoea I larvae, 10,000 1-3 year old juveniles (50% females and 50% males) and 2,609 5-15 year old adult (1,655=females, 954=males) P. camtschaticus from West Kamchatka, were intentionally released by Russian scientists in the Kolafjord in the east Barents Sea (Russia) to create a new and valuable fishing resource in the region (Orlov and Karpevich, 1965; Orlov and Ivanov, 1978). Since then, the crab has spread both east along the Kola Peninsula, and westwards into the Norwegian zone.
IntroductionsTop of page
Risk of IntroductionTop of page
Results from tag-recapture experiments carried out in the Varangerfjord, Northern Norway, reveal that adult crabs here move only short distances (2-15 nautical miles) over a three-year period. The experiments also indicate that when local stocks reach a certain density, significant migration over longer distances is observed (Sundet et al., 2000a). Tagged individuals have been found to move over significant distances over short periods of time. Further knowledge about seasonal migration patterns and density dependent emigration is necessary to understand the crab's dispersal potential to new areas (JH Sundet, Institute of Marine Research, Norway, personal communication, 2009).
Habitat ListTop of page
|Benthic zone||Principal habitat||Harmful (pest or invasive)|
Biology and EcologyTop of page
The adult crab has two migrations, a mating-moulting and a feeding migration (see Pictures). It is known from the crab's native area that the adult migrates to shallow waters in spring in connection with hatching, mating and spawning. During summer and autumn it moves to deeper waters, and over-wintering takes place at depths below 200 m. Observations in Norwegian waters show approximately the same pattern, but findings of a few adult crabs in shallow waters during the whole year indicate differences from the area of origin (Sundet et al., 2000a).
The red king crab is known to tolerate temperatures of –1.7 to +11ºC (Rodin, 1989) and this varies according to the life history stages. The West Kamchatka sub-population overwinters on the continental slope where the warmer Pacific Ocean water mixes with the colder waters of the shallow shelf. The migration period from the over-wintering area to shallow water depends on increases of the bottom water temperatures, as well as the physiological conditioning prior to spawning and moulting (Rodin, 1989). The geographical extent of the subzero temperatures influences the time of their shoreward migration. In spring, normally May-June, high densities of adults accumulate at 10-15 m where temperatures are approximately 2ºC. Following reproduction in June and July adults forage at around 50 m depth at roughly 2ºC. In cold years, where the females are unable to penetrate through the cold-water layer (-1 to –1.7ºC) and into the coastal zone, the release of larvae takes place at depths of 80 to 120 m. In these cases the larvae are transported to unfavourable areas and larval mortality is high (Rodin and Lavrentev, 1974). Red king crab populations at the West Kamchatka shelf have strong year classes appearing at approximately 5-7 years intervals (Rodin, 1989). Once temperatures decrease the crabs disperse to deeper water where they overwinter (Rodin, 1989).
Water TolerancesTop of page
|Parameter||Minimum Value||Maximum Value||Typical Value||Status||Life Stage||Notes|
|Salinity (part per thousand)||Optimum||Marine water, little is known (is found to tolerate low saline water for short time)|
|Water temperature (ºC temperature)||Optimum||–1.7 to +11 tolerated (Rodin, 1989). Varies according to life history stage|
Notes on Natural EnemiesTop of page
There are no important enemies although there have been few observations of juvenile king crab in the stomachs of large cod (Gadus morhua), wolf fish (Anarchichus minor and A. lupus) and seals.
Means of Movement and DispersalTop of page
Natural Dispersal (Non-Biotic)
Active walking by the crabs.
Ballast water may be a source of species spread.
Impact SummaryTop of page
Economic ImpactTop of page
Red king crabs caught in by-catch cause concern to fishermen as they damage fishing gear (DAISIE, 2006).
Environmental ImpactTop of page
Impact on Biodiversity
Risk and Impact FactorsTop of page Invasiveness
- Proved invasive outside its native range
- Has a broad native range
- Abundant in its native range
- Highly adaptable to different environments
- Is a habitat generalist
- Capable of securing and ingesting a wide range of food
- Highly mobile locally
- Benefits from human association (i.e. it is a human commensal)
- Long lived
- Has high reproductive potential
- Has propagules that can remain viable for more than one year
- Damaged ecosystem services
- Ecosystem change/ habitat alteration
- Modification of natural benthic communities
- Reduced native biodiversity
- Threat to/ loss of native species
- Competition - monopolizing resources
- Rapid growth
- Highly likely to be transported internationally illegally
Detection and InspectionTop of page
For information see the Sea Grant publication ‘Biological Field Techniques for Lithodid Crabs’ http://seagrant.uaf.edu/bookstore/pdfs/ak-sg-05-03a.pdf.
Similarities to Other Species/ConditionsTop of page
King crabs have a crab-like morphology and a strongly calcified exoskeleton (Cunningham et al., 1992). Furthermore, they have a fused head and thorax, an asymmetrical abdominal flap, one pair of chelipeds, three pairs of walking legs and an array of antennae and mouth parts (mandibles, maxillae and maxillipeds). P. camtschaticus is one of several species of the genus present in the subarctic areas of North Pacific Ocean and Bering Sea.
Prevention and ControlTop of page
Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.
Control by utilization
ReferencesTop of page
Anisimova N; Berenboim B; Gerasimova O; Manushin I; Pinchukov M, 2005. On the effect of red king crab on some components of the Barents Sea ecosystem/Ecosystem dynamics and optimal long-term harvest in the Barents Sea Fisheries. In: Proceedings of the 11th Russian-Norwegian Symposium, Murmansk, 15-17 August 2005. IMR/PINRO Joint Report Series, 298-306.
Gudimov AV; Gudimova EN; Pavlova LV, 2003. Effect of the Red King Crab Paralithodes camtschaticus on the Murmansk Coastal Macrobenthos: The First Estimates Using Sea Urchins of the Genus Strongylocentrotus as an Example. Doclady Biological Sciences, 393(1-6):539-541.
Hjelset AM; Sundet JH; Nilssen EM, 2009. Size at Sexual Maturity in the female red king crab (Paralithodes camtschaticus) in a newly settled population in the Barents Sea, Norway. J. Northw. Atl. Fish. Sci, 41:173-182.
Hood DW; Fisher V; Nebert D; Feder H; Mueller GL; Burrell D; Boisseau D; Goering JJ; Sharma GD; Kresge DT; Fison SR, 1974. Environmental study of the marine environment near Nome, Alaska. University of Alaska, Institute of Marine Science, 265 pp.
Jewett SC; Gardner LA; Rusanowski PM, 1982. Food and feeding habits of red king crab from north-western Norton Sound Alaska. In: Proc. Intern. Symp. King Tanner crabs, Univ. Alaska Sea Grant Rep, 219-232.
Jørgensen LL, 2006. NOBANIS - Invasive Alien Species Fact Sheet - Paralithodes camtschaticus. Online Database of the North European and Baltic Network on Invasive Alien Species - NOBANIS. http://www.nobanis.org
Jørstad KE; Smith C; Grauvogel Z; Seeb L, 2007. The genetic variability of the red king crab, Paralithodes camtschatica (Tilesius, 1815) (Anomura, Lithodidae) introduced into the Barents Sea compared with samples from the Bering Sea and Kamchatka region using eleven microsatellite loci. Hydrobiologia, 590:115-121. http://springerlink.metapress.com/content/1573-5117/
Larsen L, 1996. Temperature depended development, growth and mortality of Red king crab (Paralithodes camtschatica Tilesius) larvae in experimental conditions. Norway: Norwegian College of Fishery Science, University of Tromsø, 86 pp.
Latreille PA, 1829. [English title not available]. (Les Crustacés, les Arachnides et les Insectes, distribués en familles naturelles) In: Le Règne Animal, distribué d'après son organisation, pour servir de base à l'histoire naturelle des animaux et d'introduction à l'anatomie comparée [ed. by Cuvier G], i-xxvii,1-584.
Logvinovich DN, 1945. Aquarium observations on the feeding of the Kamchatka crab. (Akvarial'nya nablyudeniya nad pitaniem Kamchatskogo kraba) Materialy po biologii promyslu o obrabotke Kamchatskogo kraba [Materials on biology, fishery and refinement of the Kamchatka crab]. Izvestiya Tikhookeanskogo Nauchno-Issledovatel'skogo Istituta Rybnogo Khozyaistva i Okeanografii [TINRO]., 79-97.
Orlov YI; Karpevich AF, 1965. On the introduction of the commercial crab Paralithodes camtschatica (Tilesius) into the Barents Sea. In: ICES Spec. Meeting 1962 to consider problems in the exploitation and regulation of fisheries for Crustacea. Rapp. P.-v. Réun. Cons. Int. Explor. Mer [ed. by Cole HA], 59-61.
Pavlova LV; Britayev TA; Rzhavsky AV, 2007. Benthos elimination by juvenile red king crabs Paralithodes camtschaticus (Tilesius, 1815) in the Barents Sea coastal zone: Experimental data. Doklady Biological Sciences, 414:231-234.
Rodin VE; Lavrentev MM, 1974. Study of the reproduction of the Kamchatka crab in western Kamchatka. In: Gidrobiologiya i biogeografiya shel'fov Kholodnykh i umerkennykh vod mirovogo okeane. Tezisy Dokladov. [Abstracts of the Symp. on Hydrobiology and Biogeography of the shelf of the Temperate and Cold Waters of the Ocean, Leningrad, November 1974] Izdatel'stvo Nauka (Leningradskoe Otdelenie), Leningrad [ed. by Golikov AN], 65-66.
Ross DJ; Johnson CR; Hewitt CL, 2003. Variability in the impact of an introduced predator (Asterias amurensis: Asteroidae) on soft-sediment assemblages. Journal of Experimental Marine Biology and Ecology, 288:257-278.
Sundet JH; Hjelset AM, 2002. The Norwegian Red king crab (Paralithodes camtschaticus) Fishery: Management and bycatch Issues. Crabs in Cold Water Regions: Biology, Management, and Economics. Alaska Sea Grant College Programe., 681-692.
Sundet JH; Kuzmin SA; Hjelset AM; Nilsen EM, 2000. Migration and migration patterns of red king crab (Paralithodes camtschaticus) in the southern Barents Sea, Varanger Area Crab. In: 19th Lowell Wakefield Fisheries Symposium: Crabs in Cold Water Regions: Biology, Management, and Economics. Anchorage, Alaska, USA, January 17-20, 2001.
Vinogradov LG, 1969. O mekahanizme vosproizvodstva zapasov Kamchatskogo kraba (Paralithodes camtschatica) v Okhotskom more u zapadnogo poberzhya Kamchatki [The mechanism of reproduction of the stock of the Kamchatka crab (Paralithodes camtschatica) in the Okhotsk Sea off the western coast of Kamchatka]. Trudy Vsesoyuznogo Nauchno-Issledovatel'skogo Instituta Morskogo Rybnogo Khozyaistva i Okeanografi [VNIRO]. F.R.B. Can. Trans. Ser. 1540., 337-344.
OrganizationsTop of page
Norway: Institute of Marine Research (IMR), Sykehusveien 23. P.O.Box 6404. V-9294 Tromso, http://www.imr.no/en
Russian Federation: Knipovich Polar Research Institute of Marine Fisheries and Oceanography (PINRO), 183763, Knipovich Street, 6, Murmansk, http://www.ipy-care.org/index.php?s=1&rs=2&lg=en
ContributorsTop of page
24/07/09 Original text by:
Lis Lindal Jørgensen, Havforskningsinstituttet/Institute of marine Research, Sykehusveien 23, P.O.Box 6404, N-9294 Tromsø, Norway
Distribution MapsTop of page
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