Crabs

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Crabs
Fiddler crab (Uca pugilator, male)

Fiddler crab ( Uca pugilator , male)

Systematics
Trunk : Arthropod (arthropoda)
Sub-stem : Crustaceans (Crustacea)
Class : Higher crabs (Malacostraca)
Order : Decapods (decapoda)
Subordination : Pleocyemata
Partial order : Crabs
Scientific name
Brachyura
Linnaeus , 1758

The crabs (Brachyura) - also real crabs or short-tailed crabs - are the largest of the order decapods (Decapoda) with approx. 6800 species . Most crab species live in the sea, but some also live in fresh water or on land. Crabs have an abdomen (pleon) that has been transformed into a short tail plate , which lies folded down under the head-chest piece (cephalothorax) - the space in between serves as a breeding space for females.

The male mating organs (gonopods) of the crabs are derived from double- branched split feet , the latter still being found as pleopods in the females (these are used in brood care and can carry hundreds of thousands of eggs). In the males, pleopods have regressed or disappeared completely. Only the first two pairs of pleopods are regularly preserved as gonopods: the first pair is tubular, the second mostly thread-shaped and located in the tube of the first, presumably according to a piston-pump principle. The first pair of legs on the trunk has been transformed into large scissors, the eyes sit on handles. Crabs can walk sideways with remarkable speed ("crab walk").

Some species of crab are considered a delicacy , especially edible crabs , deep-sea crabs, and the Japanese giant crabs .

Various other types of cancer also have a crab-like physique and are accordingly called that, especially the stone and king crab families . In northern Germany , for example , in contrast to zoological practice, shrimps are also called “crabs” (see crab fishing ). In kitchen language, crabs are usually used to refer to shrimps - especially North Sea shrimp (see North Sea crabs ).

Systematics

The crab families :

Dromia personata
Hepatus epheliticus
Japanese giant crab ( Macrocheira kaempferi )
Atelecyclus rotundatus
Common beach crab ( Carcinus maenas )
Atergatis subdentatus
Potamon fluviatile
Western Atlantic riding crab ( Ocypode quadrata )
Harlequin Crab
( Cardisoma armatum )
Chinese mitten crab
( Eriocheir sinensis )

swell

  1. ↑ Systema Brachyurorum: Part 1. An Annotated checklist of extant Brachyuran crabs of the world. (PDF; 8.2 MB), Raffles Bulletin of Zoology. Supplement Series, No. 17, 286 pages.
  2. ↑ Sammy De Grave, N. Dean Pentcheff, Shane T. Ahyong et al. : A classification of living and fossil genera of decapod crustaceans . In: Raffles Bulletin of Zoology . Suppl. 21, 2009, pp. 1-109.

Web links

Commons : Crabs  - Collection of images, videos and audio files
Wiktionary: Krabbe  - explanations of meanings, word origins, synonyms, translations