signal crayfish, pacifastacus leniusculus, in water at sandy river bank. north american crayfish, invasive species in europe

pacifastacus leniusculus exoskeleton california freshwater crustacean unpolluted washington nocturnal crayfish american invasive wildlife species natural habitat pincers closeup abdomen lobster culture finland germany britain america signal europe nature animal plague detail nordic spring summer autumn oregon sweden water sandy river north japan brook claws creek stone party idaho czech spain great bank wild sand lake food