Intertaxon relationships
Astacus astacus (Linnaeus, 1758) - European Crayfish 
Austropotamobius torrentium (Schrank, 1803) - Stone Crayfish
Pontastacus leptodactylus (Eschscholtz, 1823) - Narrow-clawed Crayfish
Faxonius limosus (Rafinesque, 1817) - Spiny-cheek Crayfish
Pacifastacus leniusculus (Dana, 1852) - Signal Crayfish
Procambarus clarkii (Girard, 1852) - Red Swamp Crawfish