Marble crayfish - the next threat?

Recently Cefas (The Centre for Environment, Fisheries and Aquaculture Science) has become aware of an increase in the numbers of illegal crayfish for sale in aquatic outlets and garden centres. Of particular concern is the number of marble crayfish being found.

Marble crayfish are a species that first appeared in the aquarium trade in Germany and Austria in the mid-1990s. It is thought to be an American species and therefore a carrier of crayfish plague, a fungal infection to which our native crayfish specie is highly susceptible. The marble crayfish can reproduce a-sexually, where one adult can produce 270 or more young every 6-8 weeks (under optimal conditions). This means that only one animal is required to establish a breeding population. Marble crayfish can survive in temperate water and there is a concern that it will become established in the UK.

We request that anyone holding marbled crayfish, or who may have information concerning the source of this species in the UK, please contact the Fish Health Inspectorate at Cefas on 01305 2066734 or e-mail on Fish.Health.Inspectorate@Cefas.co.uk. It is imperative that this species is stopped from spreading into the wild.

Please remember that it is illegal to keep any species of crayfish other than the tropical red-clawed crayfish (Cherax quadricarinatus) for ornamental purposes.

It is imperative that some basic facts concerning marble crayfish are established and that action is taken to prevent its establishment in the wild:

• How extensively can this species be found throughout the aquarium trade of England and Wales.
• The aquatics trade needs to be notified of the potential problems that this species presents.
• Further introduction of this species into Britain needs to be prevented.
• What is the true identity of this species?
• Has this species been released into the wild in England and Wales? If so where and how established are these populations?
• Can this species carry, or is it susceptible to the crayfish plague, and what other disease risks might this species pose?
• Further information of the life cycle of this species is required
• What impact would this species have on the wild if it were released into British waterways?
• What is the capability of this species to compete with our native species?