Cambarus from kammaros: lobster (Greek) + robustus: robust, large (in reference to the robust chelae)
Big water crayfish, like many other crayfish with discrete and isolated populations represent a species complex (source). The group is often treated as separate species, with much of their diversity coming from the established patchy and isolated populations down in the Appalachians. Some of these populations are stable, while others are threatened by habitat loss (source).
They are usually found in faster flowing rivers with rocky substrates, though they can also be found in rocky sections of ponds and lakes. Big water crayfish have a higher tolerance for pollution, sediment load, and acidity than most crayfish. As a result, their range has steadily expanded in the recent past.
Our two Cambarus species are both far less synchronous in their molting and life stages than Faxonius species.