Neolithodes grimaldii

The porcupine crab is dark red in colour. It is covered in spines, which are long and robust in large adults and very long and thin in juveniles and medium-sized individuals.{{sfn|Macpherson|1988|p=44}} The rest of the surface is mostly smooth.{{sfn|Macpherson|1988|p=44}} Its prominent rostrum at the front consists of a long basal spine and two well-developed dorsal spines to either side.{{sfn|Macpherson|1988|p=44}} Its carapace length up to {{cvt|18|cm|in}} and can weigh as much as {{cvt|2.28|kg|lb}}. In healthy adults, average carapace length is about {{Convert|9.5|cm|in|abbr=on}} in females and about {{Convert|12|cm|in|abbr=on}} in males;{{sfn|Furey|2016|p=45}} however, they are often parasitised by the sterilising barnacle Briarosaccus callosus (family Peltogastridae), which causes both sexes to grow up to be significantly smaller than healthy individuals.{{sfn|Furey|2016|p=17}}{{sfn|Furey|2016|p=30}} Its walking legs are long; the second pair is the longest, and its third walking legs are more than three times as long as the carapace.{{Sfn|Macpherson|1988|p=47}}

The porcupine crab is found on muddy bottoms on the continental slope in the North Atlantic.{{sfn|Macpherson|1988|p=45}} In the western Atlantic, it ranges from eastern Canada and Greenland south as far as North Carolina in the United States. In the eastern Atlantic, it ranges from Iceland to Madeira, Portugal and Cape Verde, including the Porcupine Seabight and Rockall Trough off Ireland.{{Cite journal |last1=Quigley |first1=Declan T. G. |last2=Flannery |first2=Kevin |date=April 1997 |title=Neolithodes grimaldii Milne Edwards & Bouvier 1894 (Lithodes goodei Benedict 1895) (Crustacea: Decapoda: Anomura) in Irish offshore waters |url=https://www.researchgate.net/publication/277142759 |journal=Irish Naturalists' Journal |volume=25 |issue=10 |pages=373–374 |jstor=25536085 |access-date=14 May 2020 |via=ResearchGate}}{{Cite thesis |last=Furey |first=Greg |title=Prevalence and effects of rhizocephalan (Cirripedia: Briarosaccus callosus) parasitism and assessment of post-capture survival using the reflex action mortality predictor (RAMP) method on the deep water Porcupine crab (Neolithodes grimaldii) captured on the Labrador Shelf in the Northwest Atlantic. |date=December 2016 |access-date=14 May 2020 |degree=Masters of Science |publisher=Memorial University of Newfoundland |url=https://research.library.mun.ca/12624/1/thesis.pdf |archive-url=https://web.archive.org/web/20200514092541/https://research.library.mun.ca/12624/1/thesis.pdf |archive-date=14 May 2020 |via=Memorial University Libraries |url-status=live}}{{Failed verification|date=May 2025}} It has been recorded at depths of {{cvt|329-5230|m|ft}}.{{Cite report |url=https://spo.nmfs.noaa.gov/sites/default/files/legacy-pdfs/CIRC407.pdf |title=Distribution of Decapod Crustacea Off Northeastern United States Based on Specimens at the Northeast Fisheries Center, Woods Hole, Massachusetts |last1=Williams |first1=Austin B. |author-link=Austin B. Williams |last2=Wigley |first2=Roland L. |date=December 1977 |publisher=National Oceanic and Atmospheric Administration |issue=407 |page=9 |access-date=14 May 2020 |archive-url=https://web.archive.org/web/20200514092833/https://spo.nmfs.noaa.gov/sites/default/files/legacy-pdfs/CIRC407.pdf |archive-date=14 May 2020 |url-status=live |series=NOAA Technical Report NMFS}} Based on radio tagging, some individuals will stay in a region for months, but others may move quite long distances.{{sfn|Davidson|Hussey|2019|p=1}}

Neolithodes grimaldii was first described in 1894 by carcinologists Alphonse Milne-Edwards and Eugène Louis Bouvier while performing research for Albert I, Prince of Monaco of the House of Grimaldi.{{sfn|Milne-Edwards|Bouvier|1894|pp=62–63}} Initially calling it Lithodes Grimaldii, they differentiated the holotype – about {{Convert|45|mm|in|abbr=on}} long and taken from the island of Newfoundland – from the recently described Lithodes agassizii{{Efn|name=agassizii|Now Neolithodes agassizii}} by its more prominent spines.{{sfn|Milne-Edwards|Bouvier|1894|pp=62–63}} They subsequently placed it into its own genus, Neolithodes, on account of it sharing many features with Lithodes but differing in its abdomen, which they compared to the monotypic genus Dermaturus.{{sfn|Milne-Edwards|Bouvier|1894|pp=91–92}} The following year, carcinologist James Everard Benedict described Lithodes goodei from the East Coast of the United States, again comparing it to L. agassizii,{{Efn|name=agassizii}} but this was later shown to be a junior synonym of N. grimaldii.{{Sfn|Benedict|1895|p=479–480}}{{cite WoRMS|last=Ahyong|first=Shane T.|author-link=Shane T. Ahyong|date=13 May 2022|title=Lithodes goodei Benedict, 1895|id=590152|access-date=19 May 2025}}

N. grimaldii, along with N. capensis, N. diomedeae, N. vinogradovi, and N. yaldwyni, belongs to a subgroup of Neolithodes in which "the carapace and [walking] legs at most bear scattered, minute secondary spines or tubercles amongst the primary dorsal spines".{{sfn|Ahyong|Dawson|2006|p=52}} N. grimaldii{{'}}s relationship to other king crabs can be seen in the following cladogram:{{Cite journal|last1=Noever|first1=Christoph|last2=Glenner|first2=Henrik|date=2017-07-05|title=The origin of king crabs: hermit crab ancestry under the magnifying glass|url=http://macroecointern.dk/pdf-reprints/Noever_ZJLS_2018.pdf|url-status=live|journal=Zoological Journal of the Linnean Society|volume=182|issue=2|pages=300–318|doi=10.1093/zoolinnean/zlx033|archive-url=https://web.archive.org/web/20190716022005/http://macroecointern.dk/pdf-reprints/Noever_ZJLS_2018.pdf|archive-date=2019-07-16|via=the University of Copenhagen}}

{{Lithodidae cladogram}}

The porcupine crab is frequently caught as bycatch for Greenland halibut (Reinhardtius hippoglossoides).{{sfn|He|2005|p=35}} In 1996, approximately {{Convert|767|t|ST lb|abbr=out}} were caught and discarded in Canadian waters alone.{{sfn|He|2005|p=42}} Their survival rate is about 75% if they are not injured while being captured and released from the bottom gillnet; this decreases to about 30% when injured from rough handling.{{sfn|Furey|2016|p=59}}

Attempts have been made by fisheries since the 1990s to target the porcupine crab, which has been successfully processed and marketed in test studies.{{Sfn|He|2005|p=36}} However, low catch rates when using baited pots – considered the only viable option{{sfn|Davidson|Hussey|2019|p=1}} – have hindered these attempts.{{Sfn|He|2005|p=36}} Additionally, attempts to sell porcupine crabs caught as bycatch have failed due to the "extremely time consuming" process of removing them from the gillnet.{{sfn|Davidson|Hussey|2019|p=1}} Due to the porcupine crab population's high biomass, evidenced by the amount of bycatch, researchers believe that a fishery can still develop around the porcupine crab if its behavior is better-understood.{{sfn|Davidson|Hussey|2019|p=1}}{{sfn|Furey|2016|p=1}}

{{Notelist}}

{{Reflist}}

{{Refbegin}}

• {{Cite book |title=Crustacés décapodes provenant des campagnes du yacht l'Hirondelle (1886, 1887, 1888) |last1=Milne-Edwards |first1=Alphonse |author-link1=Alphonse Milne-Edwards |last2=Bouvier |first2=Eugène Louis |author-link2=Eugène Louis Bouvier |year=1894 |series=Résultats des Campanges Scientifiques Accmplies sur son Yacht par Albert Ier Prince Souverain de Monaco |location=Monaco |language=fr}}
• {{Cite journal|title=Descriptions of new genera and species of crabs of the family Lithodidae with notes on the young of Lithodes camtschaticus and Lithodes brevipes|last=Benedict|first=James Everard|date=1895|journal=Proceedings of the United States National Museum|volume=17|pages=479–488|doi=10.5479/si.00963801.17-1016.479 |url=https://www.biodiversitylibrary.org/part/52151|via=the Biodiversity Heritage Library}}
• {{Cite journal |last=Macpherson |first=Enrique |date=1988 |title=Revision of the family Lithodidae Samouelle, 1819 (Crustacea: Decapoda: Anomura) in the Atlantic Ocean |url=https://decapoda.nhm.org/pdfs/12339/12339.pdf |url-status=live |journal=Monografías de Zoología Marina |language=en, es |volume=II |pages=9–153 |issn=0213-4020 |archive-url=https://web.archive.org/web/20200514090605/https://decapoda.nhm.org/pdfs/12339/12339.pdf |archive-date=14 May 2020 |via=the Natural History Museum of Los Angeles County}}
• {{Cite journal|last=He|first=Pingguo|date=August 2005|title=Characteristics of bycatch of porcupine crabs, Neolithodes grimaldii (Milne-Edwards and Bouvier, 1894) from deepwater turbot gillnets in the northwest Atlantic|journal=Fisheries Research|volume=74|issue=1–3|pages=35–43|doi=10.1016/j.fishres.2005.04.002|bibcode=2005FishR..74...35H }}
• {{Cite journal|last1=Ahyong|first1=Shane T.|author-link1=Shane T. Ahyong|last2=Dawson|first2=Elliot W.|date=28 August 2006|title=Lithodidae from the Ross Sea, Antarctica, with descriptions of two new species (Crustacea: Decapoda: Anomura)|journal=Zootaxa|volume=1303|issue=1|pages=45–68|doi=10.11646/zootaxa.1303.1.3}}
• {{Cite journal|last=Heegaard|first=P. E.|date=1941|title=The Zoology of East Greenland – Decapod Crustaceans|journal=Meddelelser om Grønland|volume=126|issue=6|pages=1–72}}
• {{Cite journal|last1=Davidson|first1=E. R.|last2=Hussey|first2=Nigel Edward|date=December 2019|title=Movements of a potential fishery resource, porcupine crab (Neolithodes grimaldii) in Northern Davis Strait, Eastern Canadian Arctic|journal=Deep Sea Research Part I: Oceanographic Research Papers|volume=154|pages=103143|bibcode=2019DSRI..15403143D|doi=10.1016/j.dsr.2019.103143}}

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• {{Commons category-inline|2=Neolithodes grimaldii}}
• {{Wikispecies-inline|2=Neolithodes grimaldii}}
• [https://www.descna.com/en/speciesrecords/crustaceans/crabs-lobsters-and-crayfish/neolithodes-grimaldii-porcupine-crab Images of Neolithodes grimaldii] from Deep Sea Creatures of the North Atlantic

{{Lithodidae}}

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{{Portal bar|Crustaceans|Marine life}}

Category:King crabs

Category:Crustaceans described in 1894

Category:Anomura of the Atlantic Ocean

Category:Taxa named by Alphonse Milne-Edwards

Category:Taxa named by Eugène Louis Bouvier