The Savannah darter (''Etheostoma fricksium'') 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

Edisto Edisto Island is one of South Carolina's Sea Islands, the larger part of which lies in Charleston County, with its southern tip in Colleton County. The town of Edisto Beach is in Colleton County, while the Charleston County part of the island is u ...

Combahee The Combahee River ( ) is a short blackwater river in the southern Lowcountry region of South Carolina formed at the confluence of the Salkehatchie and Little Salkehatchie rivers near the Islandton community of Colleton County, South Carolina ...

, Broad and

Savannah River The Savannah River is a major river in the southeastern United States, forming most of the border between the states of South Carolina and Georgia. Two tributaries of the Savannah, the Tugaloo River and the Chattooga River, form the norther ...

drainages in

South Carolina )''Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = " Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = ...

and Georgia. It inhabits gravel riffles, gravel and sand runs of creeks and small rivers. This species can reach a length of .

Description

Darters have fusiform, cylindrical bodies, large paired fins and poorly developed

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled Organ (anatomy), organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their curren ...

s; they rest on the

substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (locomotion), the surface over which an organism lo ...

, using their pectoral fins to prop themselves up. The Savannah darter has a maximum total length of but a more typical length is . Males are usually larger than females, but females are more abundant. The dorsal fin has 10 or 11 spines and 12 soft rays, the pectoral fin has 13 to 14 rays and the anal fin has 2 spines and 8 to 9 rays. This fish has a small conical head and a broad tan or golden stripe running along the spine, flanked on either side by a dark stripe. This is variable in color and sometimes appears faded, but the pale dorsal stripe is always distinct. The flanks have eight to twelve dark vertical bars or series of dark blotches. In breeding males these are separated by reddish streaks while the breeding female's coloring is much more subdued. The front dorsal fin has a narrow dusky green border and a broad red marginal stripe in males and a narrow red stripe in females. The caudal peduncle has a row of three or four, somewhat irregular, dark spots.

Distribution and habitat

The Savannah darter is native to the southeastern United States, where it occurs in

and Georgia in the

Savannah A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the Canopy (forest), canopy does not close. The open canopy allows sufficient light to rea ...

and Broad River basins, below the

fall line A fall line (or fall zone) is the area where an upland region and a coastal plain meet and is typically prominent where rivers cross it, with resulting rapids or waterfalls. The uplands are relatively hard crystalline basement rock, and the coa ...

. Its typical habitat is in riffles and fast-flowing sections of creeks and small rivers, over sand and gravel substrates, in the vicinity of aquatic vegetation or woody debris, or under overhanging banks.

Ecology

The Savannah darter feeds mainly on aquatic

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s, particularly

chironomids The Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species s ...

, but also consumes

worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete wor ...

s, small

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

and terrestrial insects. It searches for food among aquatic vegetation and woody debris. Breeding takes place in the spring, when the water temperature is between . The female lays small clutches of sticky eggs which she buries in gravel or sand; the fish become mature before the end of their first year and live for up to three years.

Status

The Savannah darter is a common species and is widespread in the smaller streams of the river basins it inhabits. It is facing no particular threats and the population seems stable. For these reasons, 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 ...

References

{{Taxonbar, from=Q3765979 Etheostoma Freshwater fish of the United States Endemic fish of the United States Endemic fauna of the Southeastern United States Fish described in 1923 Taxa named by Samuel Frederick Hildebrand