The Swannanoa darter (''Etheostoma swannanoa'') is a species of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

, a darter from the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Etheostomatinae Etheosomatidae is a species rich subfamily of freshwater ray-finned fish, the members of which are commonly known as the darters. The subfamily is part of the family Percidae which also includes the perches, ruffes and pikeperches. The family i ...

, part of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Percidae The Percidae are a family of ray-finned fish, part of the order Perciformes, which are found in fresh and brackish waters of the Northern Hemisphere. The majority are Nearctic, but there are also Palearctic species. The family contains more than ...

, which also contains the

perch Perch is a common name for fish of the genus ''Perca'', freshwater gamefish belonging to the family Percidae. The perch, of which three species occur in different geographical areas, lend their name to a large order of vertebrates: the Percif ...

es, ruffes and pikeperches. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the eastern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

where it occurs in the drainage of the

Tennessee River The Tennessee River is the largest tributary of the Ohio River. It is approximately long and is located in the southeastern United States in the Tennessee Valley. The river was once popularly known as the Cherokee River, among other names, ...

. It prefers flowing water in riffles in cool, clear mountain streams, with boulder substrates. The diet and natural history of this species have been little studied but are probably similar to those of its close relative, the

greenside darter The greenside darter (''Etheostoma blennioides'') is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. It inhabits swift ...

(''Etheostoma blenniodies''). The population trend of this fish seems to be stable and it is a common species with numerous sub-populations over its limited range, and the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed its conservation status as being of "

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

Distribution

The Swannanoa darter has a relatively limited distribution compared to some other etheostomid darters. It can be found in the southern Appalachian Mountain headwaters of the Tennessee River and other areas in East Tennessee, Southwest Virginia, and Western North Carolina. It is found in the Clinch and Powell River systems in Virginia and through the upper Holston and French Broad River systems along the Tennessee, Virginia, and North Carolina borders. Although it has been documented in the Clinch and Powell River systems in Virginia, it is not found in these same systems in Tennessee. ''E. swannanoa'' was found only sporadically in the Tennessee River headwaters and specifically in the Clinch, Holston, Watauga, and Nolichucky Rivers. It prefers cold, clear water with boulder substrates.

Ecology

The Swannanoa darter prefers flowing water in riffles pools in cool, clear mountain streams. For the

(''Etheostoma blenniodies''), a close relative of the Swannanoa darter found in similar areas, juveniles mostly eat midge larvae and microcrustaceans. Adults have more varied diets, primarily made up of mayflies and caddisflies. Adults also eat midge, black fly, and other aquatic insect larvae. In some areas, such as the Little River of Tennessee, adults ate many ''Leptoxis'' spp. snails. Feeding intensity is much less in winter and greatest in May and June. Juvenile specimens were lacking in summer and early fall collections.Etnier and Starnes 1993 This suggests the juvenile habitat is different from the adult habitat. Pollution from mining operations and the impoundment of streams and rivers throughout the Swannanoa darter's range has possibly resulted in declines in distribution.

Lifecycle

Unfortunately, not much is known about the lifecycle of Swannanoa darters compared to some other members of the genus ''Etheostoma''. The breeding season of the Swannanoa darter is in early spring, and has been observed to occur on 2 April. Greenside darters also spawn in early spring, when water temperatures reach 50-53 °F and this is probably similar to the time when Swannanoa darters breed. Swannanoa darters spawn on variable substrates, and these may include vegetation, sand, or rock substrates. Sexual maturity is usually achieved at about one year of age, and growth is rapid. Lengths of about 45 mm are achieved after the first year of growth, as well. Adults can reach up to 90 mm in length. Greenside darters, which share many lifecycle characteristics with Swannanoa darters, usually live for about five years.

Management

Currently, little to no active management is used specifically for the Swannanoa darter. Trout, which are often associated with Swannanoa darters, drive much of the current management of the streams and rivers where these darters are found because of their recreational and economic value in the southern Appalachian Mountains. Much of the current range of the Swannanoa darter lies within protected areas in national forests and parks, but any activity that increases sedimentation or decreases water flow could negatively impact this species. Activities with a potential for negative effects include careless logging, mining, development, and impoundment of streams and rivers. In the lower elevations and larger water bodies where these darters are found, pollution and contaminants could also pose problems for this species. The use of streamside management zones (SMZs), an excellent management practice used to protect stream health and water quality, in turn benefits these darters. Water quality monitoring, including water chemistry, temperature and dissolved oxygen, would be helpful to obtain baseline data and monitor for possible negative trends. Due to the lack of research on ''E. swannanoa'', current management should also include research to gain knowledge on specific habitat needs for this fish.NatureServe. 2012.(Etheostoma swannanoa) 2012. WWW.NatureServe.org

References

{{Taxonbar, from=Q2117160 Etheostoma Freshwater fish of the United States Fauna of the Southeastern United States Ecology of the Appalachian Mountains Freshwater fish of the Southeastern United States Least concern biota of the United States Fish described in 1889 Taxa named by David Starr Jordan Taxa named by Barton Warren Evermann