So far it lacks a Swedish name, but the Latin one is Nippoleucon himinensis.
The five-millimeter-long crayfish lives in bottom sediments and has previously been observed in both Germany and Finland.
The species is harmless to humans and animals, the Västernorrland County Administrative Board says in a press release, but how it affects its surrounding environment is unknown.
"We do not yet know what effects the new species may have, but we know that it is much easier to prevent spread than to deal with possible consequences afterwards," says environmental officer Tove Lönneborg in the press release.
She urges bathers, fishing enthusiasts and boat owners to empty, wash and dry any equipment being moved.
