Narrow-clawed crayfish
Astacus leptodactylus
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Photo credit: Trevor Renals
Astacus leptodactylus - Narrow-clawed crayfish
Habitat:
Description:
Origin and Distribution:
Impacts:
Is it found in Northern Ireland?
How could it get here?
Prevent Spread
You can help by reporting any sightings: @ the Centre for Environmental Data & Recording (CEDaR) - Or via the iRecord App.
Current Legislation Position (Northern Ireland only):
Astacus leptodactylus - Narrow-clawed crayfish
Habitat:
- Lives in range of freshwater habitats such as lakes and rivers
- Can also survive in brackish waters and can tolerate high salinities
- They can move overland to reach new freshwater habitats
Description:
- Can range in colour from pale yellow or pale to dark green or occasionally blue. Mottling of pale individuals and leg joints are generally orange
- Can reach up to 30cm with ridged eye sockets and a long rostrum which has parallel sides
- Claws are long and narrow with a rough upper surface
- Females produce 200-400 eggs per year, and hatch in late spring
Origin and Distribution:
- Native to west Asia and eastern Europe
- First arrived in southwest England in the 1970s
- Introduced for sale in markets
- Populations mostly in southeast England with small populations in other areas of England and Wales
Impacts:
- Can impact macrophyte abundance and habitat structure
- Have a wide-ranging diet so can impact the entire food web
- Potentially outcompetes the native crayfish where ranges overlap
- Can affect fishing industry by outcompeting fish for food and causing fish mortality
Is it found in Northern Ireland?
- Not currently in Northern Ireland.
How could it get here?
- Was introduced to western Europe from Turkey for fish markets so could spread to NI through trade and accidental introduction
Prevent Spread
- Do not release animals into or move animals between waterbodies
- Check boats when being taken out of water or moved between waterbodies
- Report all sightings
- Great care must be taken to ensure individuals kept in confinement do not escape
You can help by reporting any sightings: @ the Centre for Environmental Data & Recording (CEDaR) - Or via the iRecord App.
Current Legislation Position (Northern Ireland only):
- Astacus leptodactylus is listed in Schedule 9 of the Wildlife (Northern Ireland) Order 1985 and as such, under Article 15 it is an offence to release or allow this species to escape into the wild.