Crab
Fiddler crab ( Uca pugilator )
The crab ( Brachyura ) - also real crab or short-tailed crabs - are approximately 6800 species, the largest infraorder of the order decapods. Most species live in the sea, but some in fresh water or on land. Crabs have a reshaped to a short tail plate abdomen ( pleon ), which is folded under the head chest piece ( cephalothorax ) - the space is used in females as breeding space.
The male copulatory organs ( gonopods ) of crabs derived from doppelästigen gap feet from, the latter still find as pleopods in females (these are used in the care of the brood and can carry hundreds of thousands of eggs ). In the male pleopods are degenerated or disappeared completely. Only the first two Pleopodenpaare are regularly obtained as gonopods: The first pair is tubular, the second usually filiform and located in the tube of the first, probably by a piston - pump principle. The first pair of legs of the hull is formed into large claws, the eyes are on stalks. Crabs can remarkably quickly move sideways ( " crab ").
Some crab species are considered a delicacy, especially crabs, deep sea crabs and the Japanese giant crabs.
Also various other cancers have a shrimp-like physique and, accordingly, so called, in particular the family of stone and king crabs. In the kitchen with language are usually crabs shrimp, specifically meant brown shrimp.
System
The families of the crabs:
- Podotremata de Haan, 1833 Superfamily Cyclodorippoidea Ortmann, 1892 Cyclodorippidae Ortmann, 1892
- Cymonomidae Bouvier, 1897
- Phyllotymolinidae Tavares, 1998
- Homolodromiidae Alcock, 1900
- Sponge crabs ( Dromiidae ) De Haan, 1833
- Dynomenidae Ortmann, 1892
- Homolidae De Haan, 1839
- Langbein crabs ( Latreilliidae ) Stimpson, 1858
- Poupiniidae Guinot, 1991
- Raninidae De Haan, 1839
- Symethidae Goeke, 1981
- Heterotremata Guinot, 1977 Superfamily Dorippoidea MacLeay, 1838 Dorippidae MacLeay, 1838
- Orithyiidae Dana, 1853
- Boxer crabs ( Calappidae ) Milne Edwards, 1837
- Hepatidae Stimpson, 1871
- Ball crab ( Leucosiidae ) Samouelle, 1819
- Matutidae De Hann, 1841
- Epialtidae MacLeay, 1838
- Inachidae MacLeay, 1838
- Inachoididae Dana, 1851
- Triangle crabs, spider crabs, spider crabs, decorator crabs ( Majidae ) Samouelle, 1819
- Mithracidae Balss, 1929
- Pisidae Dana, 1851
- Tychidae Dana, 1851
- False spider crabs ( Hymenosomatidae ) MacLeay, 1838
- Aethridae Dana, 1851
- Dairidae Ng & Rodriguez, 1986
- Daldorfiidae Ng & Rodriguez, 1986
- Parthenopidae MacLeay, 1838
- Retroplumidae Gill, 1894
- Atelecyclidae Ortmann, 1893
- Crabs, rock crabs ( Cancridae ) Latreille, 1802
- Cheiragonidae Ortmann, 1893
- Corystidae Samouelle, 1819
- Pirimelidae Alcock, 1899
- Thiidae Dana, 1852
- Carcinidae Mac Leay, 1838
- Catopidae Borradaile, 1902
- Deep-sea crabs ( Geryonidae ) Colosi, 1923
- Macropipidae Stephenson & Campbell, 1960
- Primelidae Alcock, 1899
- Swimming crabs ( Portunidae ) Rafinesque, 1815
- Thiidae Dana, 1852
- Bythograeidae Williams, 1980
- Carpiliidae Ortmann, 1893
- Eumedonidae Dana, 1853
- Goneplacidae MacLeay, 1838
- Hexapodidae Miers, 1886
- Rock crabs ( Menippidae ) Ortmann, 1893
- Panopeidae Ortmann, 1893
- Wool crabs ( Pilumnidae ) Samouelle, 1819
- Platyxanthidae Guinot, 1977
- Pseudorhombilidae Alcock, 1900
- Coral crabs ( Trapeziidae ) Miers, 1886
- Around crabs ( Xanthidae ) MacLeay, 1838
- Belliidae Dana, 1852
- Deckeniidae Ortmann, 1897
- Platythelphusidae Colosi, 1920
- Potamidae Ortmann, 1896
- Potamonautidae Bott, 1970 Sudanonautes Bott, 1955
- Pseudothelphusidae Ortmann, 1893
- Gecarcinucidae Rathbun, 1904
- Parathelphusidae Alcock, 1910
- Gallkrabben ( Cryptochiridae ) Paulson, 1875
- Superfamily Pinnotheroidea De Haan, 1833 Pinnotheridae De Haan, 1833
- Camptandriidae Stimpson, 1858
- Soldier crabs ( Mictyridae ) Dana, 1851
- Ocypodidae Rafinesque, 1815
- Palicidae Bouvier, 1898
- Land crabs ( Gecarcinidae ) MacLeay, 1838
- Glyptograpsidae Schubart, Cuesta & Fields, 2002
- Square crabs ( Grapsidae ) MacLeay, 1838
- Plagusiidae Dana, 1851
- Sesarmidae Dana, 1851
- Varunidae Milne Edwards, 1853