Endangered

There is only one native crayfish species in Great Britain: the white-clawed crayfish (Austropotamobius pallipes). The Extinction Countdown blog is reporting that the International Union for Conservation of Nature and Natural Resources (IUCN) has made the white-clawed crayfish officially endangered.

What does this have to do with Marmorkrebs? Marmorkrebs have never been found in the wild in Great Britain, but they’ve shown up in the pet trade there at least once. More generally, nobody has shown whether Marmorkrebs can be a carrier of crayfish plague.Given that most North American species can carry it, it seems highly likely. But even if they can, that’s not a guarantee that they normally do. For all we know, Marmorkrebs in people’s aquaria in Europe may never have come into contact with crayfish plague.

More information about the conservation issues around UK crayfish can be found at Buglife (registration required).

The Buglife website says this about Marmorkrebs:

Marbled crayfish (Procambarus sp.)

This species originates from the USA, but its full identification needs to be confirmed. The Marbled crayfish is the first recorded crayfish capable of breeding when only females are present, by parthenogenesis (asexual reproduction). They are also crayfish plague carriers and voracious feeders. Although Marbled crayfish are banned from import or sale it is likely that some are being kept illegally by hobby aquarists. As it only takes one crayfish to start a population, aquarium tanks are easily over-run by them and the juveniles are very good at escaping. There is a huge risk that people may release Marbled crayfish. If this happens it won’t be long before they are found in the wild and spreading along our rivers. There are no known UK sites in the wild so far.

Photo by fotoARION on Flickr; used under a Creative Commons license.