Marbled crayfish

Procambarus fallax f. virginalis


Photo credit: ©Cefas
Procambarus fallax f. virginalis
Common Names:
  • Marbled crayfish

  • Freshwater standing water, such as ponds

  • The marbled crayfish is a medium-sized crayfish with a distinct marbled pattern, with brown, green or blue colours, and small claws.
  • It is the only crayfish with the capacity to clone itself. All individuals are female which means the offspring are genetically identical to the parent.

Origin and Worldwide Distribution:
  • It has escaped or been released into the wild in Croatia, the Czech Republic, Germany, Italy, the Netherlands, and Slovakia. Its origin is unknown.

Potential or Known Impacts:
  • Although the species is still quite limited in distribution and there is little evidence of it having a major impact so far, it could potentially become a major threat to native European crayfish species through competition and the spread of the crayfish plague.
  • As other introduced crayfish, it is also likely to disrupt natural wetlands through its extensive burrowing activities.

How could it get here?
  • Through the aquarium trade, although a ban on keeping or releasing it is in force to keep it from spreading across Europe.

Is it found in Northern Ireland?
  • Not present in Northern Ireland.

Methods for Prevention:
  • A ban on keeping, including in aquaria, or releasing the species, pathway management and the rapid eradication of any newly emerging populations will prevent the species from being introduced into other parts of the EU.
  • Report all sightings.

You can help by reporting any sightings: @ the Centre for Environmental Data & Recording (CEDaR) - Or via the iRecord
Current Legislative Position (Listed on 03 August 2016)
  • This species must not intentionally be brought into the Union; kept; bred; transported to, from or within the United Kingdom, unless for the transportation to facilities in the context of eradication; placed on the market; used or exchanged; permitted to reproduce, grown or cultivated; or released into the environment.
For further queries, you can contact the Invasive Non Native Species (INNS) Team in the Northern Ireland Environment Agency on 028 9056 9558 or Email:
Invasive Species Northern Ireland

Invasive Species Northern Ireland