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Distribution of the Tennessee dace, Phoxinus tennesseensis, in northeast Tennessee.

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ABSTRACT -- Eleven historic and 41 potential new locations were surveyed from September 1998-April 2001 to determine the current distribution of Phoxinus tennesseensis in northeast Tennessee and if current protection is warranted. Phoxinus tennesseensis were found to inhabit 5 (45%) historic and 4 (9.8%) new streams sampled. Dip nets proved to be the most efficient method of collection. Phoxinus tennesseensis always were found in pools with mostly (89%) silt substrates and woody vegetation growing along the banks. All pools had undercut banks and 67% of pools had root masses hanging into the water, which served as a refuge for adult and especially juvenile fish. Phoxinus tennesseensis were observed spawning over nests of Campostoma anomalum in Trinkle Creek and Timbertree Branch (Sullivan County). There was a slight decrease in the total number of populations in northeast Tennessee even with the discovery of 4 new populations. Possible reasons for the decline include excess silt, removal of streamside woody vegetation, and severe drought. We recommend that P. tennesseensis continue to be granted protection and further studies be conducted throughout its range to determine the status of all known populations.

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The Tennessee dace, Phoxinus tennesseensis is a small minnow (family Cyprinidae) occurring with a limited distribution in eastern Tennessee and extreme southwestern Virginia (Etnier and Starnes, 1993; Jenkins and Burkhead, 1994). Originally, P. tennesseensis was thought to be a variant of P. oreas (Starnes and Jenkins, 1988). However, these species can be distinguished by morphological characters. Phoxinus tennesseensis has a break in the dark lateral stripe. The eye pupil diameter of P. tennesseensis is larger than the diameter of the dark spots above the lateral stripe. However, the eye pupil diameter of P. oreas is smaller than the diameter of the dark spots above the lateral stripe (Starnes and Jenkins, 1988). Phoxinus tennesseensis is thought to be in a monophyletic group with the blackside dace, P. cumberlandensis, the mountain redbelly dace, P. oreas, and the laurel dace, P. saylori, all of which are found in Tennessee (Skelton, 2001). There are 7 North American Phoxinus species, some with uncommon distributions. Phoxinus cumberlandensis has a limited distribution and is classified as endangered (Etnier and Starnes, 1993) and P. saylori appears to have a distribution that includes only a few streams (Skelton, 2001).

Phoxinus tennesseensis is typically found in shallow pools of spring fed first order streams. The habitat surrounding the streams has shade created by woody vegetation, silt and fine gravel pools, undercut banks, and debris in the water for cover (Starnes and Jenkins, 1988). Phoxinus tennesseensis is known historically from 62 locations (Shute, 2001), all of which are streams in the upper Tennessee River drainage. A high percentage of the Tennessee P. tennesseensis population residing in spring and seepage areas is considered jeopardized (Etnier and Starnes, 1991). Due to its limited distribution, P. tennesseensis is listed as "in need of management" in Tennessee (Tennessee Wildlife Resource Agency, 2000) and "endangered" in Virginia (Virginia Game and Inland Fisheries, 1989). Phoxinus tennesseensis was classified as an S2 (very rare and imperiled) species by the Tennessee Division of Natural Heritage, but in 2001 the species was reclassified as an S3 (rare and uncommon) species due to the discovery of new populations (Tennessee Division of Natural Heritage, 2001).

In the last five years several new populations of P. tennesseensis have been located. These and other additional populations might suggest that P. tennesseensis does not need continued protection. However, if many historic locations have been extirpated the number of viable populations could be much smaller than currently documented.

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