DistributionRead full entry
Range DescriptionThis species is endemic to the Tennessee and Cumberland River drainages. It historically occurred in the Cumberland River drainage downstream of Cumberland Falls. In the Tennessee River drainage, it historically occurred from the headwaters in southwestern Virginia downstream to Muscle Shoals (Williams et al. 2008), and in the Tennessee River across northern Alabama and in some tributaries.
The species is now extirpated from Alabama (the most recent dated record was from the Estill Fork of the Paint Rock River in 1980; Williams et al. 2003), Georgia (Wisniewski pers. comm. 2007) and Copper Creek, Virginia (Hanlon et al. 2009). This extirpation in two of its three range states and at some localities in Virginia represents a range reduction of over 80% over the last 25-50 years (A. Bogan, K. Cummings and J. Cordeiro pers. comm. 2010). The estimated extent of occurrence for the species is 250-1,000 km2, and it is limited to between 1 and 20 severely fragmented locations (NatureServe 2009). Consequently, our estimated extent of occurrence does not include these severe discontinuities within the species range and is therefore significantly smaller than the mapped range extent.
Still, several populations remain in isolated stretches of the Big South Fork (Scott County, Tennessee, and McCreary County, Kentucky) although the identity of these populations may be in question (USFWS 2003, 2004). Populations are also extant in the Tennessee River system in the Clinch River (Russell and Scott Counties, Virginia and Hancock County, Tennessee), Powell River (Lee County, Virginia), North Fork Holston River (Scott County, Virginia - reintroduced), Nolichucky River (Cocke and Hamblen Counties, Tennessee), and Duck River (Maurey and Marshall Counties, Tennessee); while it may still be extant in Copper Creek (Jones et al. 2001, USFWS 2003, 2004). There is also high potential for the discovery of new populations of the species (J. Cordeiro pers. comm. 2012).