Tasmanian giant crab
{{Short description|Species of crab}}
{{Speciesbox
| image = Cua Tasmania.jpg
| image_caption =
| genus = Pseudocarcinus
| species = gigas
| authority = (Lamarck, 1818)
| synonyms = Cancer gigas Lamarck, 1818
| synonyms_ref = {{cite web |author=Peter Davie |year=2010 |title=Pseudocarcinus gigas (Lamarck, 1818) |publisher=World Register of Marine Species |url=http://www.marinespecies.org/aphia.php?p=taxdetails&id=440496 |accessdate=October 9, 2010}}
}}
The Tasmanian giant crab (Pseudocarcinus gigas), also known as the Tasmanian king crab, giant deepwater crab, giant southern crab, queen crab, or bullcrab, is a very large species of crab that resides on rocky and muddy bottoms in the oceans off Southern Australia.{{SeaLifeBase species | genus = Pseudocarcinus | species = gigas | month = December | year = 2013}}Levings, A.H. & P.C. Gill (2010). Seasonal Winds Drive Water Temperature Cycle and Migration Patterns of Southern Australian Giant Crab Pseudocarcinus gigas. In: G.H. Kruse, G.L. Eckert, R.J. Foy, R.N. Lipcius, B. Sainte-Marie, D.L. Stram, & D. Woodby (eds.), Biology and Management of Exploited Crab Populations under Climate Change. {{ISBN|978-1-56612-154-5}}. doi:10.4027/bmecpcc.2010.09 It is the only extant species in the genus Pseudocarcinus.{{cite journal |journal=Raffles Bulletin of Zoology |year=2008 |volume=17 |pages=1–286 |title=Systema Brachyurorum: Part I. An annotated checklist of extant Brachyuran crabs of the world |author=P. K. L. Ng, D. Guinot & P. J. F. Davie |url=https://lkcnhm.nus.edu.sg/wp-content/uploads/sites/10/app/uploads/2017/04/s17rbz.pdf}}
Habitat
The Tasmanian giant crab lives on rocky and muddy bottoms in the oceans off Southern Australia on the edge of the continental shelf at depths of {{convert|20|-|820|m}}. It is most abundant at {{convert|110|-|180|m}} in the summer and {{convert|190|-|400|m}} in the winter. The seasonal movements generally follow temperature as it prefers {{convert|12|-|14|C|F|abbr=on}}. The full temperature range where the species can be seen appears to be {{convert|10|-|18|C|F|abbr=on}}.{{cite book |author=Poore, G.C.B. |year=2004 |title=Marine Decapod Crustacea of Southern Australia: A Guide to Identification |page=445 |publisher=CSIRO Publishing | isbn=0-643-06906-2}}
Description
File:J J Wild Pseudocarcinus cropped.jpg
File:Tasmanian Giant Crab.jpg, Australia]]
The Tasmanian giant crab is one of the largest crabs in the world, reaching a mass of {{convert|17.6|kg|abbr=on}} and a carapace width of up to {{convert|46|cm|abbr=on}}.
{{cite web
| url = https://shapingtasmania.tmag.tas.gov.au/M/object.aspx?id=52
| title = Giant crab – a goliath amongst crustaceans
| author = Tasmanian Museum and Art Gallery
| author-link = Tasmanian Museum and Art Gallery
| date = 2013-02-12
| website = Shaping Tasmania: a journey in 100 objects
| publisher = Department of Economic Development, Tourism and the Arts.
| access-date = 2024-08-13
}}
Among crabs, only the Japanese spider crab (Macrocheira kaempferi) can weigh more. Male Tasmanian giant crabs reach more than twice the size of females,{{cite book |author=D. R. Currie & T. M. Ward |year=2009 |url=https://www.pir.sa.gov.au/__data/assets/pdf_file/0006/231783/No_345_SA_Giant_Crab_Fishery_Assessment_Report_2007_08Final_Report_published_alias.pdf |title=South Australian Giant Crab (Pseudocarcinus gigas) Fishery |id=Fishery Assessment Report for PIRSA |publisher=South Australian Research and Development Institute |accessdate=9 December 2013}} which do not exceed {{convert|7|kg|abbr=on}}. Males have one normal-sized and one oversized claw (which can be longer than the carapace width), while both claws are normal-sized in females. This crab is mainly whitish-yellow below and red above; the tips of the claws are black.{{cite book |author=N. Coleman | authorlink= Neville Coleman |year=1991 |title=Encyclopedia of Marine Animals | publisher=Blandford, Villiers House | page =107|isbn=0-7137-2289-4}} Small individuals are yellowish-and-red spotted above.
Behaviour
The Tasmanian giant crab feeds on carrion and slow-moving species, including gastropods, crustaceans (anomura and brachyura) and starfish. Cannibalism also occurs. They breed in June and July, and the female carries the 0.5–2 million eggs for about four months. After hatching, the planktonic larvae float with the current for about two months before settling on the bottom. The species is long-lived and slow-growing; juveniles moult their carapace every three-four years and adult females about once every nine years. This greatly limits the breeding frequency, as mating is only possible in the period immediately after the old carapace has been shed, and the new is still soft.
Fishery
The Tasmanian giant crab has been commercially fished in Tasmanian waters since 1992 and a minimum size was established in Australia in 1993. Fishing is typically by pots in water deeper than {{convert|140|m|ft|abbr=on}}. Following concerns surrounding the sustainability of catch numbers, the total allowable catch was adjusted for 2024/25 quota year to {{convert|20.7|t|lb}}.{{cite web |url=https://fishing.tas.gov.au/commercial-fishing/commercial-fisheries/giant-crab-fishery |title=Giant crab fishery |date= |publisher=Department of Natural Resources and Environment Tasmania |accessdate=2024-08-13}} valued at about A$2 million. The Tasmanian giant crab is very long-lived and slow-growing, making it vulnerable to overfishing. Before export, they are sometimes kept alive in tanks with water that is {{convert|10|-|14|C|F|abbr=on}}.
References
{{reflist|25em}}
External links
- {{commons category-inline|Pseudocarcinus gigas|Pseudocarcinus gigas}}
{{Edible crustaceans}}
{{taxonbar|from=Q2707649}}
{{DEFAULTSORT:crab, giant, Tasmanian}}
Category:Crustaceans of Australia
Category:Commercial crustaceans