The trispot darter (''Etheostoma trisella'') 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 northern Georgia and southern

Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...

in the

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

Conasauga River The Conasauga River is a river that runs through southeast Tennessee and northwest Georgia. The Conasauga River is longU.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 27, 2011 an ...

and its tributaries and historically in the

Alabama River The Alabama River, in the U.S. state of Alabama, is formed by the Tallapoosa and Coosa rivers, which unite about north of Montgomery, near the town of Wetumpka. The river flows west to Selma, then southwest until, about from Mobile, it un ...

system. It requires two interconnecting habitats; outside the breeding season it occupies the peripheral zones of the main river, with slow-moving water and silt gravel substrates with vegetation cover; during the breeding season it moves to warmer water with a clay-bottomed substrate with much vegetation. The population of this fish is declining due to loss of suitable habitat because of stream impoundment and land development. 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 " vulnerable".

Distribution

The trispot darter is endemic to the

and its tributaries located in northern Georgia and southern

. The species was thought to be extinct from its historical range for seven years, until a specimen was found in north Georgia in 1967. The historical range was in the

system and as far south as the

Coosa River The Coosa River is a tributary of the Alabama River in the U.S. states of Alabama and Georgia. The river is about long.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 27, 2011 ...

, and in some Georgia rivers. The species also was found in a reservoir,

Lake Weiss A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

. Other recent efforts to find the darter have not been successful; it is now only found in the Conasauga and in Alabama's Big Canoe Creek. The reason for the decline in distribution is thought to be due to human impact and development.

Silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel when ...

in water affects egg survival, and correct water temperature is vital for the species' breeding. The Conasauga River offers the critical, undisturbed habitat for the species.

Habitat and ecology

''E. trisella'' requires two separate but interconnected habitats. When not breeding, it occupies the peripheral zones of the main river, with slow-moving water and silt gravel substrates with vegetation cover. The breeding habitat is much warmer water (water at is best for egg maturation), and usually is a clay-bottomed substrate with heavy vegetation seepage.Ryon, M.G. 1986. The Life-History and Ecology of ''Etheostoma trisella''. American Midland Naturalist 115:73-86 Chironomidae larvae account for 70% of the diet of this darter; Ephemeroptera nymphs account for another 19%, as measured by examining the fish's stomach contents. The species coexists with several other species in its habitat, such as the

central stoneroller The central stoneroller (''Campostoma anomalum'') is a fish in the family Cyprinidae endemic to North America. Biology Stonerollers have a rounded snout overhanging a crescent-shaped mouth, a hard ridge of cartilage on the lower lip, and irreg ...

(''Campostoma anomalum''),

southern studfish The southern studfish (''Fundulus stellifer'') is a ray-finned fish of the family Fundulidae, the tooth carps, that is native to the southeastern United States. Description The southern studfish is long. The male has elongated posterior dorsal ...

(''Fundulus stellifer''), and

Coosa darter The Coosa darter (''Etheostoma coosae'') 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 is endemic to the eastern ...

(''Etheostoma coosae''). The species' only real competitor is the Coosa darter, because its mouth size and body length allow it to be a threat for food and space. The main natural predators of the species are from the black basses (genus ''

Micropterus ''Micropterus'' is a genus of North American freshwater fish collectively known as the black bass, belonging to the sunfish family (biology), family Centrarchidae of order (biology), order Perciformes. They are sometimes erroneously called "bla ...

''). The average

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

of the fish is .

Life history

The trispot darter has an average life span around 2.5 years.Etnier, D.A. 1970. Additional Specimens of '' Etheostoma trisella'' from Tennessee. Copeia 2:365-400 They spawn around January through March, when males' skin becomes brilliantly pigmented. The skin color is thought to in attracting mates. Egg clutch numbers vary from 50 to 300 eggs per female.Ramsey, J.S., and Mount, R. H. 1986. Trispot Darter. Vertebrate animals of Alabama in need of special attention 20-21

Conservation and management

The species is listed as being threatened with extinction and is on the decline. Loss of habitat through land development and stream impoundment is the primary reason for the species' decline.Howell WM, Caldwell, RD 1967.: Discovery of a Second Specimen of Darter ''Etheostoma trisella''. COPEIA 1:235-248

References

{{Taxonbar, from=Q305803 Freshwater fish of the United States Etheostoma Fish described in 1963 Taxonomy articles created by Polbot