Maja squinado

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Maja squinado

Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Infraorder: Brachyura
Family: Majidae
Genus: Maja [1]
Species: M. squinado
Binomial name
Maja squinado
(Herbst, 1788)

Maja squinado (the European spider crab, spiny spider crab or spinous spider crab) is a species of migratory crab found in the north-east Atlantic and the Mediterranean Sea [2]. It feeds on a great variety of organisms, with seaweeds and molluscs dominating in winter, and echinoderms such as sea urchins and sea cucumbers in summer [3]. Females can produce up to 4 broods per year [4].

Migrations generally take place in autumn [5], with some crabs covering over 100 miles (160 km) in eight months [6].

M. squinado is the subject of commercial fishery, with over 5,000 tonnes caught annually, more than 70% of it off the coast of France, over 10% off the coast of the United Kingdom, 6% from the Channel Islands, 3% from each of Spain and Ireland, 2% from Croatia, 1% from Portugal, and the remainder coming from Serbia and Montenegro, Denmark and Morocco [7], although official production figures are open to doubt [2]. The European Union imposes a minimum landing size of 120 mm for M. squinado [8], and some individual countries have other regulations, such as a ban on landing egg-bearing females in Spain and a closed season in France and the Channel Islands [2].

All crabs are vulnerable to predation when moulting, and M. squinado becomes gregarious around that time, presumably for defense against predators [9].

A review of the species complex around M. squinado was able to differentiate between specimens from the Mediterranean Sea and those from the Atlantic, and concluded that the Atlantic specimens were a separate species, called Maja brachydactyla Balss, 1922 [10]. The specific epithet squinado derives from the Provençal name for the species — "squinado", "esquinade", "esquinado" or "esquinadoun" — recorded by Rondelet as early as 1554 [6].

[edit] References

  1. ^ The genus Maja is sometimes spelled Maia.
  2. ^ a b c Carl Meyer. Maja squinado, the European Spider Crab: Biology and Fishery.
  3. ^ Bernardez, C., J. Freire & E. Gonzalez–Gurriaran, (2000). Feeding of the spider crab Maja squinado in rocky subtidal areas of the Ria de Arousa (north-west Spain). Journal of the Marine Biological Association of the United Kingdom 80 (1): 95–102. doi:10.1017/S0025315499001605. 
  4. ^ L. Garcia–Florez & P. Fernandez–Rueda (2000). Reproductive biology of spider crab females (Maja brachydactyla) off the coast of Asturias (north-west Spain). Journal of the Marine Biological Association of the United Kingdom 80 (6): 1071–1076. doi:10.1017/S0025315400003131. 
  5. ^ E. Gonzalez–Gurriaran, J. Freire & C. Bernardez (2002). Migratory patterns of female spider crabs Maja squinado detected using electronic tags and telemetry. Journal of Crustacean Biology 22 (1): 91–97. doi:10.1651/0278-0372(2002)022[0091:MPOFSC]2.0.CO;2. 
  6. ^ a b (French) Le Foll, D. (1993-11-01). Biology and fisheries of the spider crab Maja squinado (Herbst) in western English Channel. Ph.D. thesis, Université de Bretagne Occidentale.
  7. ^ Global Capture Production 1950–2004. Food and Agriculture Organization (2006-09-09).
  8. ^ Council Regulation (EEC) No 3094/86 (1986-10-07). Official Journal of the European Economic Community. 
  9. ^ Sampedro, M. P. & E. Gonzalez–Gurriaran (2004). Aggregating behaviour of the spider crab Maja squinado in shallow waters. Journal of Crustacean Biology 24 (1): 168–177. doi:10.1651/C-2404. 
  10. ^ Neumann, V. (1998). A review of the Maja squinado (Crustacea : Decapoda : Brachyura) species-complex with a key to the eastern Atlantic and Mediterranean species of the genus. Journal of Natural History 32 (10–11): 1667–1684. doi:10.1080/00222939800771191. 
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