Crayfish

Noble crayfish (Astacus astacus )

The superfamily of crayfish is a taxon of higher crustaceans ( Malacostraca ). This family includes, among others, the noble crayfish, which is also known as the European crayfish.

All species that are included in this superfamily are characterized by a similar division of the body into head - thoracic area ( front body) and gegliedertem abdomen from. Both are of a thick shell ( carapace ) covered. At the front body sit five pairs of legs, the foremost pair of legs has been transformed into large claws. The remaining serve as walking legs, which also depend on gills, which breathes the crayfish.

Way of life

Crayfish are crepuscular and nocturnal. Most species are solitary. Because they are sensitive to contamination of their habitat, crayfish are within certain limits, an indicator of the biological water quality of a site.

Nutrition

Crayfish grab prey with their large claws. The smaller shearing of the second and third pair of legs running divide the spoils and carry them to the mouth.

Crayfish are omnivores: they capture aquatic insects, worms, newts, frogs, snails, mussels and fish, if they are to capture. Lighter than healthy animals are about sick fish and carrion to obtain, which are therefore more frequently on the menu of the crayfish. Crayfish also are not afraid to eat by molting temporarily become vulnerable conspecifics. However, water plants, autumn leaves, algae and musty wood they eat you.

System

The crawfish are divided into three families: the species of the northern hemisphere in the families Astacidae and Cambaridae and the southern hemisphere in the family Parastacidae. Astacidae occur in Europe, Canada and the United States. Cambaridae there are in China, Japan, Russia, Mexico and the United States, introduced in Europe. Parastacidae are common in Australia, New Zealand, New Guinea, Madagascar, and South America.

The southern group of Parastacidae was separated after the breakup of the super continent Pangaea from the northern groups. Therefore Sometimes the Parastacidae be placed in its own superfamily of Parastacoidea in the scheme. Astacidae Cambaridae and then alone form the superfamily Astacoidea. It is clear, however, that all three families are more closely related to each other than to the other groups of large crabs.

• Astacidae Noble crayfish (Astacus astacus Linnaeus, 1758)
• Galician crayfish (Astacus leptodactylus Eschscholtz, 1823)
• Clawed crayfish ( Austropotamobius pallipes Lereboullet, 1858)
• Stone crayfish ( Austropotamobius torrentium cabinet, 1803)
• Signal crayfish ( Pacifastacus leniusculus Dana, 1852)

• Striped dwarf crayfish ( Cambarellus patzcuarensis Villalobos, 1943)
• American crayfish ( Orconectes limosus Rafinesque, 1817)
• Kalikokrebs ( Orconectes immunis Hagen, 1870)
• Redswamp crayfish ( Procambarus clarkii ( Girard, 1852) )
• Marble cancer Procambarus
• Blue Florida Cancer ( Procambarus alleni ( Faxon, 1884) )

Fossil also several other families are known, including the Erymidae and Cricoidoscelosidae.