signal crayfish, pacifastacus leniusculus, climbs on stone in water at river bank. north american crayfish, invasive species.

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