Conservation assessment and habitat notes for three rare Alabama crayfishes: Cambarus Cracens, Cambarus Scotti, and Cambarus Unestami

Over seventy percent of the world's freshwater crayfish species are found within the United States, and much of this diversity is concentrated in the southeastern United States. Yet many of these species remain understudied. Of particular interest is the conservation status of these understudied taxa. We conducted fieldwork in 2011 across northeastern Alabama and northwestern Georgia to review the occurrence, habitat, and in some cases, local population densities of three crayfish species (Cambarus scotti, C. unestami, and C. cracens) to determine current distributions in relation to historical surveys. All three species occur in flowing small to medium-sized streams with firm substrates of gravel, cobble, and bedrock. Two species (C. scotti and C. unestami) have stable populations, occurring at 79% and 90%) of sites surveyed, respectively. In contrast, surveys for the third crayfish species (C. cracens) indicated a need for conservation action, with this species occurring at a single site.