Common name: Snail Darter
available through www.itis.gov
Identification: Page (1983); Page and Burr (1991); Etnier and Starnes (1993).
Size: 9 cm.
Native Range: Upper Tennessee drainage of eastern Tennessee, northern Georgia, and Alabama, including Little Tennessee River, Watts Bar Reservoir below Fort Loudon Dam, South Chickamauga Creek, lower portion of Big Sewee Creek in Meigs County, lower Sequatchie River in Marion County, Little River in Blount County, lower French Broad River in Sevier County, and lower Paint Rock River in Madison County, Alabama (Page and Burr 1991; Etnier and Starnes 1993).
Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Percina tanasi are found here.
Table last updated 12/4/2021
† Populations may not be currently present.
Ecology: Inhabits clean gravel or sandy shoals in large creeks and rivers (Boschung and Mayden 2004; Ashton and Layzer 2008). Prefers areas lacking aquatic macrophytes and with low degrees of turbidity or siltation (Ashton and Layzer 2008).
Diet primarily consists of snails, but also consumes trichopteran, dipteran, and ephemeropteran larvae (Boschung and Mayden 2004).
Means of Introduction: The Snail Darter was intentionally introduced to create an additional population of this endangered fish when its only known habitat was threatened by construction of a dam. Seven hundred and ten Snail Darters were introduced into the Hiwassee River from June 1975 to February 1976 (U.S. Fish and Wildlife Service 1982a; Etnier and Starnes 1993). In October 1975, 61 were introduced into the Nolichucky River. Introductions into the Nolichucky River were halted when the sharphead darter Etheostoma acuticeps was discovered there, for fear the introduction would jeopardize this rare species (U.S. Fish and Wildlife Service 1982a; Etnier and Starnes 1993). The Holston River was stocked with 533 Snail Darters from the Hiwassee and Little Tennessee rivers during the period 1978 to 1979. The Elk River was stocked in July 1980 with 425 Snail Darters from the Little Tennessee River (U.S. Fish and Wildlife Service 1982a).
Status: Established in Hiwassee River and range expanding (U.S. Fish and Wildlife Service 1982a). One darter observed in Nolichucky River in 1980. Single individual possibly from small reproducing population or escapee from fish hatchery upstream; none found since. Elk River populations apparantly extirpated due to failed introduction (Etnier and Starnes 1993). Snail Darters found in lower French Broad and lower Holston rivers in 1988 and 1989 presumably represent progeny of Holston River transplants (Etnier and Starnes 1993). In 2005, Ashton and Layzer (2008) found robust populations in French Broad and Hiwassee Rivers, and low abundances in Holston, Little, and Sequatchie Rivers and Big Sewee and South Chichamauga Creeks. Ashton and Layzer (2008) suggested that these low population sizes may be due to a lack of reproducing populations in these streams, with individuals migrating into these streams from larger, reproducing populations in French Broad and Hiwassee Rivers.
Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.
References: (click for full references)
Ashton, M.J. and J.B. Layzer. 2008. Distribution of the threatened snail darter (Percina tanasi
) in the upper Tennessee River drainage. Journal of the Tennessee Academy of Science 83(3-4):52-56.
Boschung, H.T., and R.L. Mayden. 2004. Fishes of Alabama. Smithsonian Books, Washington, DC.
Etnier, D.A., and W.C. Starnes. 1993. The fishes of Tennessee. University of Tennessee Press, Knoxville, TN.
Lee, D.S., C.R. Gilbert, C.H. Hocutt, R.E. Jenkins, D.E. McAllister, and J.R. Stauffer, Jr. 1980 et seq. Atlas of North American freshwater fishes. North Carolina State Museum of Natural History, Raleigh, NC.
Page, L.M. 1983. Handbook of darters. T.F.H., Inc., Neptune City, NJ.
Page, L.M. and B.M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Guide Series, vol. 42. Houghton Mifflin Company, Boston, MA.
U.S. Fish and Wildlife Service. 1982a. Snail darter recovery plan.
Species profile for Percina tanasi
- U.S. Fish and Wildlife Service, Environmental Conservation Online System
Animal Diversity Web - Universit of Michigan Museum of Zoology
Pam Fuller, and Matt Neilson
Revision Date: 8/16/2011
Peer Review Date: 8/16/2011
Pam Fuller, and Matt Neilson, 2021, Percina tanasi Etnier, 1976: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=827, Revision Date: 8/16/2011, Peer Review Date: 8/16/2011, Access Date: 12/4/2021
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.