Corrugated darter | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Perciformes |
Family: | Percidae |
Genus: | Etheostoma |
Species: | E. basilare |
Binomial name | |
Etheostoma basilare | |
The corrugated darter (Etheostoma basilare) 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 United States only known from Caney Fork, Tennessee, where it has been shown to have as many as five subgroups. [2] They are active hunters which prey on insects, fry, and possibly young snails. Multiple species and subspecies of these darters can coexist where substrate is varied, so this must be carefully preserved to accommodate many similar species. [3] With the warming of spring, E. basilare enters its breeding cycle and males develop their dimorphic coloration. Like most darters, it hugs the stream bed, using its body shape and fin posture to maintain its position. [4]
This lifestyle which is so dependent upon the benthic architecture of the stream is highly impacted by disturbance, which can be the result of increased or decreased flow from dams, introduction of polluted debris, or particulate size change due to erosion. Dams, in particular, pose a large threat to this species due to the effects of siltation, which can over time fill in streambed substrate gaps, destroying nesting sites and suffocating any eggs already laid. In addition, different species and subspecies of darter are highly adapted to a given substrate size, which insinuates that this habitat homogenization could result in a negative impact on the existent E. basilare subspecies diversity and on the darter ecological balance as a whole. [5]
The corrugated darter is endemic to the upper section of the Caney Fork and Collins River in eastern Tennessee, both of which are part of the Cumberland River drainage. [1] It has been consistently present in this area since its original speciation, upon which its geographic home has had considerable influence. Formed by the abundance of melt from the receding North American glaciers, which presumably carried the darter ancestor with it, this part of the river system has been mostly isolated from neighboring water systems by this drastic geographic change, creating a likely environment for the genetic deviation of many darter species, E. basilare included. This effect can also be observed at a smaller scale. Conditions in this part of the river have enabled the corrugated darter to further diverge into five closely related subgroups, highlighting the adaptability of the species and how even small habitat differences can drive divergence. [2]
No study has yet been made of the corrugated darter's feeding habits, but many of its relatives are active predators, hunting insects and fry while situationally consuming detritus. The closely related E. barbouri, or teardrop darter, is known to eat fly and mayfly larva, augmenting this diet with decaying leaves and other decomposing biomatter in the water. It is likely preyed upon by local bass, trout, sculpin, reptiles, and salamanders as adults, as well as by carnivorous aquatic insects as fry. [6] This species competes most strongly on an interspecific level, as can be seen in the resulting five subspecies. In similar species, the greatest factor in the balance of these cohabitating darters is the size of the substrate in the river bed. Being a benthic species, this creates a number of microhabitats which allow these subspecies to coexist with its own preferred territory. [4] Darters inhabit most water depths up to a meter as adults, depending on substrate size, but greatly prefer the protection of shallow riffles as fry. As adults, they also enter these areas to breed. [6]
In related darters, sexual maturity is often reached at a year old. The breeding season is estimated to be from April to May annually, but depends greatly on water temperature, which causes the sexual reaction to take place. Males and females of many darter species do exhibit obvious sexual dimorphism, with bright mating displays present in the males, but no such information indicates the presence or lack of these colors for E. basilare. Most darters have shown a preference for moderately shallow riffles during the breeding season, where the running water may aid oxygen dispersion to the eggs and provide a safer nursery for the fry. They nest under flat rocks, where the males aggressively guard their clutch of eggs laid by multiple females, whose average egg deposition varies widely between species; this figure for E. basilare is not known. [6] The corrugated darter may participate in egg-mimicking behavior, using the spots on their pectoral fins to entice prospective mates, which prefer experienced males already guarding eggs, into depositing in their nest. They have been recorded as reaching 5.5 cm in length; the average lifespan of this species is not documented. [7]
The corrugated darter is rated as “Least Concern” by the IUCN Red List of Threatened Species. [1] As of yet, this species has seen little habitat disruption, having no major damming or construction projects in the area. The nearest dam, Dale Hollow, is located further down the Caney Fork's flow. The greatest risk this structure presents to the species is found in the lake behind it, which has been stocked with potential predators - walleye and several species of crappie and bass. [8] The threat of extinction due to this is minimal, however, as the previously mentioned fish are all popular sport fish, subject to frequent reduction by human predation. In addition, this fish exhibits high fecundity, doubling its population in as few as 15 months, making it particularly resistant to predation, though possibly more vulnerable when breeding sites are disturbed and it is unable to adequately recoup its population loss. [7] In many species of darter, hybridization is a major concern, since they are closely related and use external fertilization. In E. basilare, however, this is probably not the case. The existence of their many subspecies may indicate the detrimental effects of hybridization are minimal, either due to some form of sperm exclusion or perhaps resulting from the localization of the subspecies in relation to their optimal habitats. [9]
The rainbow darter is a small 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 native to North America where it is found in small, fast-moving streams and small to medium-sized rivers. It grows to 2 to 3 inches in length. The species is very sensitive to pollution and silt, staying in clean, pollution-free water. The rainbow darter is easily identified by three dark spots on the back, and blue and orange in the dorsal and anal fins.
The trispot darter 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 northern Georgia and southern Tennessee in the United States, where it occurs in the Conasauga River and its tributaries and historically in the Alabama River 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 has assessed its conservation status as being "vulnerable".
The blenny darter 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 a poorly known species which occurs in Alabama and Tennessee where it inhabits swift riffles.
The greenside darter 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 riffles in the eastern United States and southern Ontario.
The bluemask darter 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 United States. It is a federally listed endangered species of the United States. This fish was not formally described until 2009, but it was added to the US Endangered Species List in 1993. During breeding, the male has bright blue patches on its head and other areas. This fish is found only in the Caney Fork River system, a tributary of the Cumberland River in Tennessee. The species name akatulo comes from the Cherokee for "mask", referring to the solid blue coloration on the lower face of the fish.
The Cumberland snubnose darter 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. This species is found in the middle Cumberland River drainage in Tennessee, Kentucky, Virginia, North Carolina, Georgia, and Alabama. It is absent in reaches above the Big South Fork, rare in North Carolina, and absent in western tributaries of the Tennessee River. While research on the ecology of E. atripinne is not extensive, what is known is they are usually found in small to medium freshwater streams in gravel riffle areas where their eggs can attach to the substrate and be left unguarded. E. atripinne can be found within a wide range of depths in its environment, leading its being classified as benthopelagic. While its global status is secure, the American Fisheries Society labels it with a status of “Special Concern”.
The emerald darter, 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 found only in northern and eastern Kentucky and northeastern Tennessee.
The splendid darter 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 Barren River system in south-central Kentucky and north-central Tennessee. This species is usually found in small rocky pools on the sides of creeks and rivers.
The orangefin darter 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 found in Barren River and Green River systems in Tennessee and Kentucky.
The buffalo darter 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 found in the tributaries of the lower Duck and lower Tennessee Rivers. It is distinguished from other darter species by the presence of eight anal rays, as well breeding males having a unique hump behind the head reminiscent of a buffalo.
The greenfin darter 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 United States.
The greenbreast darter 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 southeastern United States, where it occurs in the systems of the Alabama River and the Black Warrior River. It is an inhabitant of streams and rocky riffles of creeks and smaller rivers. This species can reach a length of 7.9 cm (3.1 in), though most only reach about 5 cm (2.0 in).
Etheostoma rufilineatum, the redline darter, 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 southeastern United States.
The snubnose darter 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 southeastern United States.
The Citico darter is a threatened species 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 native to Tennessee. This species was formerly subsumed within Etheostoma percnurum. The E. percnurum group now consists of four distinct species: E. percnurum, E. marmorpinnum, E. lemniscatum, and E. sitikuense.
The wounded darter 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 United States. Its range includes the upper Tennessee River drainage, western Virginia, western North Carolina, and eastern Tennessee. Its typical habitat is among boulders or coarse rubble and cobble, often with overhanging ledges, in medium to large slow-moving rivers. It feeds on small insect larvae, especially midge larvae. Spawning occurs when the water warms up in late spring. Females deposit clutches of adhesive eggs on the underside of rock ledges or slabs, and the male guards the nest. The population trend of this fish seems to be decreasing slowly but it is a relatively common species with numerous sub-populations, and the International Union for Conservation of Nature has assessed its conservation status as being of "least concern". The greatest threat comes from impoundment, and a management plan is in place, including captive breeding.
Etheostoma zonale, the banded darter, 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 United States. It is mainly found in the Mississippi Basin, ranging from the Verdigris River in Kansas eastward to the Allegheny River in New York, and from the Minnesota River in Minnesota southward to the Ouachita River in Arkansas and the Tennessee River in Alabama. Its typical habitat in small and medium-sized rivers is riffles over cobble or gravel, rock slabs, and small boulders. It feeds on the riverbed on small insect larvae and is itself eaten by birds and larger fish. Males become more colorful and become territorial before spawning which takes place in spring. The females attach the eggs to waterweed. The population trend of this fish seems to be stable, it is a common species with numerous sub-populations over a wide range, no major threats have been identified and the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".
The Christmas darter i is a species of ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae which includes the perches, ruffes and pike-perches. It is found in the Savannah, Ogeechee and Altamaha catchment areas in South Carolina and Georgia. It is a small but colorful fish, typically less than 5 cm (2 in) in total length, with blackish, red and green streaks on its flanks. Green and red are associated with Christmas, hence the common name Christmas darter. Like other darters, it lives on or close to the stream-bed, in riffles and vegetation-laden stretches of small rivers, creeks and spring-fed streams. It feeds on aquatic insects and probably breeds in the spring, but its biology and behavior are poorly known.
Nothonotus is a genus or subgenus 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 southeastern United States. First proposed as a sub-genus of Etheostoma in 1988, there is still debate regarding the appropriate taxonomic rank of Nothonotus in the literature. Darter species comprise more than 180 of the Percidae taxa.
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 is endemic to North America. It consists of 3-5 different genera and well over 200 species.