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

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