About Faxonius immunis (Hagen, 1870)
Faxonius immunis (Hagen, 1870) is similar to multiple other crayfish species in the genus Faxonius. Although the colouration of its claws is distinctive, identifying a specimen by this trait is difficult without reference specimens for comparison. F. immunis can be told apart from F. virilis by a notch located near the base of the dactylus, or finger, of the claw; this notch is not present on F. virilis claws. F. immunis occurs only in slow-flowing bodies of water, including streams, ponds, marshes, and roadside ditches. This differs from F. virilis, which also inhabits moderately flowing rivers. F. immunis can survive in areas that experience large fluctuations in available water: it burrows into the ground when surface waters recede.
