Signal crayfish: Where It Lives, Map & Facts

Where the signal crayfish lives – recorded in 11 countries, with quick facts from Wikidata and an introduction from Wikipedia.

Scientific name	Pacifastacus leniusculus
Group	Crabs, lobsters & shrimps
Status	Least concern (Wikidata, IUCN category label)
Found in	11 countries
Continents	Europe, North America
Class	Crustacean
Order	Decapoda
Family	Astacidae

Where does the signal crayfish live?

Open-licence (CC0 / CC BY) wild records published on GBIF place the signal crayfish in 11 countries and territories across Europe and North America. In Austria, Belgium, Switzerland, Germany, Denmark, Spain, United Kingdom, Luxembourg, Sweden, United States it is listed as introduced (GRIIS checklists via GBIF).

France
Sweden (introduced)
United Kingdom (introduced)
Switzerland (introduced)
Belgium (introduced)
Luxembourg (introduced)
United States (introduced)
Germany (introduced)
Spain (introduced)
Austria (introduced)
Denmark (introduced)

Countries with at least a handful of records (a minimum share of the species’ records, to leave out vagrants and escapes). Records with coordinates only; captive and fossil records excluded.

Is the signal crayfish endangered?

The signal crayfish’s conservation status recorded in Wikidata is “Least concern” (an IUCN Red List category label). Source: Wikidata.

What kind of animal is the signal crayfish?

The signal crayfish (Pacifastacus leniusculus) is a crustacean in the order Decapoda and the family Astacidae, genus Pacifastacus. (Taxonomy from Wikidata.)

About the signal crayfish

Pacifastacus leniusculus, commonly known as the signal crayfish, is a species of freshwater crayfish in the family Astacidae, native to western North America. They are thought to have originated from the Columbia River Basin.

Physically, they are characterized by a smooth carapace and a distinctive white to pale blue-green patch at the base of the claw joint. Reminiscent of the white flags that signalmen used for directing trains, this light patch is responsible for the species' common name. Due to its heightened aggression and opportunistic polytrophic diet,P. leniusculus has become an established invasive species found across North America, Europe, and Japan, displacing many of the regions’ native species.

Text in “About” is quoted from the Wikipedia article Signal crayfish (revision 1378625123), licensed under CC BY-SA 4.0. Changes: lead section excerpted verbatim, formatting removed. Quick facts, taxonomy and status: Wikidata Q693000 (CC0). Countries and pin: GBIF.org occurrence records (CC0 / CC BY 4.0).