|Scientific Name:||Etheostoma aquali|
|Species Authority:||Williams & Etnier, 1978|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
Listed as Near Threatened because extent of occurrences is less than 20,000 sq km, area of occupancy is less than 500 sq km, and the species occurs in not more than 10 locations, yet distribution and abundance currently appear to be relatively stable, so the species does not fully meet the criteria for Vulnerable. Pollution or stream alterations could easily cause a decline and qualify the species as Vulnerable.
|Range Description:||Range includes the Duck and Buffalo river systems of the lower Tennessee Basin, west-central Tennessee (Etnier and Starnes 1993). The three small specimens from Elk River and Shoal Creek mentioned in the original description of this species represent E. wapiti (Etnier and Starnes 1993). A record of E. micropelidum from the Duck River was based on a misidentified E. aquali (Etnier and Starnes 1993).|
|Range Map:||Click here to open the map viewer and explore range.|
Currently known from seven streams (Peggy Shute pers. comm. 1998). During a 1992-1993 survey of over 50 sites within the known range, collected from 8 of 17 historic locations and 7 new locations in the Duck and Buffalo systems. Some locations could not be sampled effectively due to deep water or swift current and most sites were visited only once (Cook et al. 1996). The Tennessee Valley Natural Heritage Program has recorded approximately 45 occurrences from seven streams. Some of these occurrences may no longer be extant. However, considering the difficulty in collecting the preferred habitat, the number of extant occurrences probably exceeds the number found during the 1992-1993 survey (Peggy Shute pers. comm. 1998).
This darter probably is more abundant than it appears to be; difficult to seine in preferred habitat (Etnier and Starnes 1993). During a 1992 survey, the average number yielded at 15 sites was five and the maximum number collected at a single locality was 19. Historically the maximum number collected at one locality was 27 (Cook et al. 1996; Burr et al. 1993, cited by Shute et al. in press). Page and Burr (2011) regarded this darter as "fairly common."
Populations currently appear to be stable (Peggy Shute pers. comm. 1998). During a 1992 survey, the species was found throughout most of the historical range including several new sites; the species appears to show persistence in the Duck River system (Cook et al. 1996).
|Habitat and Ecology:||Habitat includes clear, fast, rocky riffles of small to medium rivers (Page and Burr 2011). This species occurs primarily in deep riffles, runs, and flowing pools in the main channel and lower portions of small to medium rivers. It appears to prefer shoal areas (0.3-1.0 meters deep) with moderate to swift current. Preferred substrate is a mixture of gravel and cobbles with large unconsolidated rocks. Flow in some riffles may be reduced to a trickle in summer. Eggs are laid on the undersides of rocks. See Etnier and Starnes (1993).|
|Major Threat(s):||The greatest threat is the potential for loss of habitat due to impoundment. The completion of the Columbia Reservoir on the middle Duck River would eliminate many populations (Etnier and Starnes 1993). However, as of 1995 this proposed dam project has been halted. If the Tennessee Valley Authority's Columbia Dam Project is not completed as originally planned, this fish should be quite secure barring excessive pollution of habitat streams (Shute et al. pers. comm.). Other threats are difficult to identify but potentially include pollution, siltation, and large scale modifications such as dredging or channelization. This fish appears to be less susceptible to direct threats (e.g., minor stream-riparian alterations, eutrophication) (Cook et al. 1996).|
|Conservation Actions:||Intensive surveys of historical locations where the species was not found during a 1992 survey would be useful, as would long-term monitoring to determine population trends and abundance. Further research on threats is needed.|
|Citation:||NatureServe 2014. Etheostoma aquali. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 25 April 2015.|