''Austropotamobius torrentium'', also called the stone crayfish, is a

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

an species of

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

crayfish Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...

in the family Astacidae. It is mostly found in tributaries of the Danube, having originated in the northern part of the

Balkan Peninsula The Balkans ( ), also known as the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throughout the who ...

Description

''A. torrentium'' grows to a length of around , and has a smooth brown

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 ...

, with an untoothed triangular rostrum; the underside is creamy white. Males have larger claws than females, but females have a noticeably larger abdomen. As in other crayfish, the first two pairs of

pleopod The decapod ( crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various ...

s are specialised for

sperm Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...

transfer in males, while the female's pleopods are uniform, and used for brooding eggs.

Distribution

The distribution of ''A. torrentium'' is centred on the Danube system, extending from the

Olt River The Olt (Romanian and Hungarian; german: Alt; la, Aluta or ', tr, Oltu, grc, Ἄλυτος ''Alytos'') is a river in Romania. It is long, and its basin area is . It is the longest river flowing exclusively through Romania. Its average disch ...

in Romania upstream to Germany and

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

and into parts of the Rhine and Elbe basins. It is widespread in southern Germany,

, Austria, Hungary, Slovenia, Croatia and Serbia. Contrary to some previous records, ''A. torrentium'' does not appear to occur in Luxembourg, Poland or Ukraine. In France, at the western edge of the species' range, two populations remain, one in Alsace and one in Lorraine. The Czech Republic and Slovakia are at the north-eastern periphery of the natural range of ''A. torrentium'', with only four and six known populations, respectively, all those in Slovakia being in the ' hills (Lesser Carpathians). The northernmost point inhabited by ''A. torrentium'' is near the city of Dresden in the German federal state of Saxony. Italy is at the south-western margin of the distribution of ''A. torrentium'', with at least two populations in the drainage (a tributary of the Danube) near Tarvisio. To the south-east, the species has entered the Drin River in Albania, and was discovered in 2005 in the European part of Turkey. In Romania, it is present in the Apuseni Mountains and in the

Carpathian The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe. Roughly long, it is the third-longest European mountain range after the Urals at and the Scandinavian Mountains at . The range stretches ...

foothill Foothills or piedmont are geographically defined as gradual increases in elevation at the base of a mountain range, higher hill range or an upland area. They are a transition zone between plains and low relief hills and the adjacent topograp ...

s to the southwest, overlapping slightly with the distribution of the noble crayfish '' Astacus astacus''. The populations in the west of the species' range are genetically depauperate, while populations from the upper Kupa basin are as genetically distinct from the rest of ''A. torrentium'' as some species in related genera are from each other, suggesting ''A. torrentium'' originated in the

Western Balkans The Balkans ( ), also known as the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throughout the whol ...

Ecology

The preferred habitat of ''A. torrentium'' is cold, fast-flowing streams, although some live in larger rivers and lakes. It digs

burrow An Eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of sh ...

s in the banks and hides under submerged roots or

rock Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wales ...

s, emerging at night to feed. Adult ''A. torrentium'' consume a variety of plant materials, including fallen leaves, while the juveniles chiefly feed on aquatic invertebrates. Natural predators of fully grown ''A. torrentium'' include foxes, bears, wolves,

otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine, with diets based on fish and invertebrates. Lutrinae is a branch of the Mustelidae family, which also includes wea ...

s and badgers, while the young animals are targeted by fish. The species is sensitive to low levels of dissolved oxygen, and to chemical pollution. Beside naturally occurring threats, ''A. torrentium'' has also suffered from the introduction of the

crayfish plague Crayfish plague (''Aphanomyces astaci'') is a water mold that infects crayfish, most notably the European ''Astacus'' which dies within a few weeks of being infected. When experimentally tested, species from Australia, New Guinea and Japan were a ...

, ''Asphanomyces astaci'', carried by

invasive Invasive may refer to: *Invasive (medical) procedure *Invasive species *Invasive observation, especially in reference to surveillance *Invasively progressive spread of disease from one organ in the body to another, especially in reference to cancer ...

crayfish species from

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

, and from the release of

detergent A detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. There are a large variety of detergents, a common family being the alkylbenzene sulfonates, which are soap-like compounds that are more ...

s into streams while washing

laundry Laundry refers to the washing of clothing and other textiles, and, more broadly, their drying and ironing as well. Laundry has been part of history since humans began to wear clothes, so the methods by which different cultures have dealt with t ...

Life cycle

Mating takes place at the end of October. The female then carries the 40–70 fertilised eggs on her

s until the eggs are ready to hatch. Juveniles moult up to 4 or 5 times per year, but as they mature, this slows to once or twice a year, usually in May, June or July. Sexual maturity is reached after 3 to 5 years, by which time the animal has grown to a length of . Adult males can reproduce every year, but females do not reproduce for at least one year after producing eggs.

Conservation status

''A. torrentium'' is one of the most threatened species in Europe: as well as protection under various national laws, it is designated

data deficient A data deficient (DD) species is one which has been categorized by the International Union for Conservation of Nature (IUCN) as offering insufficient information for a proper assessment of conservation status to be made. This does not necessaril ...

on the IUCN Red List, it is listed in Appendix III of the Bern Convention, and it is protected under the EU Habitats Directive.

References

{{DEFAULTSORT:Austropotamobius Torrentium Astacidae Freshwater crustaceans of Europe Crustaceans described in 1803 Taxonomy articles created by Polbot