Crayfish of the Sipsey River: A freshwater biodiversity “hotspot” in the southeastern United States

The southeastern United States contains 363 of the world’s 500 crayfish species.  Of these, 85 species have been recorded from Alabama. The habitats of these crayfish species are believed to be imperiled due to damming and urbanization, yet little is known about their distribution and ecology.  Only two major rivers in Alabama remain free flowing; only one—the Sipsey River—is without an urban center. Previous studies have shown that the Sipsey drainage is a biodiversity “hotspot” in terms of freshwater mussels (43 spp.) and fish (91 spp.). Based on these findings, we predicted that this drainage should contain similar crayfish diversity.   This prediction was tested by sampling 19 locations throughout the river drainage.  Stream crayfish were collected using minnow traps.  Burrowing species were collected by hand and via a novel trap design.  To date, 10 crayfish species have been collected; two are of conservation concern within Alabama.  The Sipsey River drainage, which encompasses 1.5% of the state, harbors 12% percent of total crayfish species richness.  This is comparable to its contribution to biodiversity of mussels (14%) and fish (30%).This study is ongoing, with future effort being focused on the survey of burrowing and large river species.