''Pontastacus leptodactylus'', the

Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , pa ...

crayfish, Galician crayfish, Turkish crayfish or narrow-clawed crayfish is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of brackish water crayfish imported and introduced to

Central Europe Central Europe is an area of Europe between Western Europe and Eastern Europe, based on a common historical, social and cultural identity. The Thirty Years' War (1618–1648) between Catholicism and Protestantism significantly shaped the area' ...

in 19th century from the

Caspian Sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

region.

Description

''Pontastacus leptodactylus'' can grow up to in length from the tip of the rostrum to the end of the

telson The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on accou ...

(tail), but is more commonly found at around in length. The sides of the

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

are very rough, usually pale yellow to pale green in colour. ''P. leptodactylus'' has two pairs of post-orbital ridges, the second of which may have spines. It also has a prominent tubercle (small nodule) on shoulder of the

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

. The claws of ''Pontastacus leptodactylus'' are long and narrow (hence the common name 'narrow-clawed crayfish'). Their upper surface is rough and the underside is the same colour as the body. A tubercle can be found on the fixed side of the claw. ''P. leptodactylus'' can be distinguished most easily from the European or broad-fingered crayfish, '' Astacus astacus'', by the relatively thinner "fingers" of the claws. Further studies done on the ''Pontastacus leptodactylus'' found that they can be co-infected by two or more different pathogens. A study done by R. Salighehzadeh saw that after collecting 10 narrow-clawed crayfish found that they contained 2 pathogenic isolates simultaneously, the ''Aeromonas hydrophilia'' and ''Fusarium solani''. Scheren des Galizischen Sumpfkrebs

Ecology

''Pontastacus leptodactylus'' is fairly docile, especially the male with large claws, and favours relatively still brackish waters such as

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s and

canal Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flow un ...

s. It is listed as a species of

Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

References

External links

{{Authority control Astacidae Freshwater crustaceans of Europe Fauna of the Caspian Sea Crustaceans described in 1823 Taxobox binomials not recognized by IUCN