Mud crayfish, papershell crayfish
Faxonius, named for Walter Faxon (1848-1920), American ornithologist and carcinologist. Former genus, Orconectes, is from Orcus, god of the underworld in Roman mythology + nectes: swimming (Greek); immunis, unclear. Calico: mottled.
You won’t have luck finding these crayfish while flipping over rocks as they prefer the muddy bottoms of wide, slow flowing rivers or lakes with no flow (they can also live in ponds that dry up during the summer or on margins of pond that may be exposed to the air). These sites are characterized by high turbidity and low oxygen levels. Their preference for these habitats may be more a result of being pushed out by the more aggressive virile crayfish. In rocky, faster flowing streams, virile crayfish out compete the calico crayfish for refugia sites in rocks, and so calicos are relegated to the open, sandy bottom areas of these rivers.
Calico crayfish will burrow to in the summer to avoid drought and heat as well as in the winter (source). And they’ll burrow deep, excavating burrows 15 inches to 4 feet deep. Burrows are often capped with mud (to prevent drying out) and end with an enlarged cavity (source). In habitats that don’t drain and/or freeze, calico crayfish will content themselves with just bury themselves in the mud. While they can mature in about four months, time spent in burrows to avoid drought comes at a cost, extending maturation into the following year.
When calico crayfish are out, mostly at night, they spend most of their time scraping algae from rocks and eating aquatic vegetation. They will also opportunistically feed on invertebrates (e.g. midge larvae, isopods, etc.), and it’s possible that they feed on seedlings and roots when confined to their burrows. They have been studied for possible application in controlling aquatic vegetation, but they are not nearly aggressive enough to make this a viable option (source).