crayfish in autumn. portrait of signal crayfish, pacifastacus leniusculus, in colorful leaves showing claws.

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