This represents most of the diversity of crayfish worldwide. The family Cambaridae, which most southeastern species belongs to, has around 430 species, of which seven occur in east Asia and the rest in eastern North America. Crayfish from west of the Continental Divide are in the family Astacidae (~16 spp.), which also occurs in Europe and the Mideast. A third family, the Parastacidae (~180 spp.), occurs in the Southern Hemisphere.
Our knowledge of many invertebrate groups is still in its infancy. The southeastern US has extremely diverse communities of aquatic snails, mussels, caddisflies, and many other insects. Even well-studied groups like freshwater fishes and amphibians still see new species described on a regular basis. Because these animals serve as an important component of aquatic food chains and affect ecosystem structure and function, it’s critical that we continue to study and conserve them.
-Dr. Dave Neely