Olive darter | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Perciformes |
Family: | Percidae |
Genus: | Percina |
Species: | P. squamata |
Binomial name | |
Percina squamata | |
Synonyms [2] | |
Etheostoma squamatumGilbert & Swain, 1887 |
The olive darter (Percina squamata) 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 native to Tennessee, Kentucky, North Carolina, and Georgia, in the United States. It is found in the headwaters of Tennessee River system and the middle reaches of the Cumberland River system, its ideal habitat being clear, cold water over rocky substrates. It grows to a length of about 5 in (13 cm) and is an insectivore, feeding mainly on insect larvae on the riverbed. The fish matures at age two and lives till about age four. Up to 1500 eggs are spawned which fall to the riverbed and get lodged among gravel. The olive darter is classified as a "vulnerable species", being affected by habitat destruction and siltation, often resulting from damming and impoundment of the rivers or the creation of weirs. It is also affected by the change in the forest riparian habitat resulting from the killing of trees by the hemlock woolly adelgid.
Their geographic range is dispersed among headwaters of the Tennessee River system from the Holston River system (Watauga River) downstream as far as the Hiwassee River system, including the Emory River, in North Carolina, Tennessee, and Georgia; and the middle Cumberland River drainage below the falls, primarily in the Rockcastle River and Big South Fork, in Kentucky and Tennessee. [3]
The olive darter is restricted to small to medium-sized streams and rivers in the upper-most portions of the Tennessee River and Cumberland River systems in Tennessee, Kentucky, North Carolina, and Georgia. In Georgia, Percina squamata is only known from the Toccoa and Little Tennessee River systems. [3] Within the Cumberland and Tennessee River systems this species occurs in Big South Fork, Coopers Creek, Betty's Creek Rockcastle River, [4] Holston River (Watauga River), Nolichucky River, and Hiawassee River. [5] Percina squamata relies on good water quality and fast-water habitats in order to survive. The largest tributaries of the Toccoa and Nottely rivers in Georgia are very similar, having clear, cold water and rocky substrates, [6] ideal conditions for the olive darter.
Olive darters are invertivores/insectivores [5] primarily feeding on benthic aquatic insects, including caddisflies and mayflies. [3] In general, darters feed opportunistically on immature insects; few taxa are consumed in greater proportions than they were found in the environment. [7] This species of darter, like many others, inhabits high-gradient streams with moderate to torrential current over rubble and boulders, deeper downstream portions of gravel riffles in streams of moderate gradient, and sometimes shallow pools with gravel or rock bottoms. [5] Being very habitat specific, it is necessary for humans to have as little influence on the streams that this species inhabits. Human activities, particularly habitat destruction and species introductions, are resulting in increased homogenization of once unique biogeographic regions. [8] Failure of Best Management Practices (BMPs) for forestry and agriculture, failure to control soil erosion from construction sites and bridge crossings, and increased stormwater runoff from developing urban and industrial areas have degraded the stream quality and pose a significant threat to the olive darters. [3] Runoff and siltation caused by increasing habitat destruction raises the temperature of the water in many streams causing a change in the microclimate needed for the inhabitants of olive darters. This leads to loss of population.
The olive darter grows up to 5 inches in length and lives for up to 4 years. Female maturity is reached at 2 years old and they have a brood size of 1,500 in order to make up for the lack of a brood guarder. Eggs are dispersed out in the open and then fall down into rock-gravel. [4]
The maximum lifespan of the olive darter is around four years with an average lifespan of three years. This darter reaches sexual maturity halfway through its life at two years. [4] Reproductive condition of adults and the timing of young-of-year recruitment indicate a May–July spawning season. [3] They spawn in rock-gravel shoals [4] where the female will drop her eggs and the males fertilize the eggs. This reproductive strategy allows for protection of the brood without the use of a brood guarder. [4] Nearly 1,500 eggs are in a single brood [4] allowing for a higher chance of survival. This is a common reproductive strategy for many darters. At full maturity the male will reach about 5 cm [4] and the female will only be slightly smaller.
The olive darter depends on good water quality and fast-water habitats in upland streams. Impoundments have reduced available habitat for the olive darter, and remaining free-flowing mountain streams are vulnerable to degradation by excessive inputs of silt and sediment. Human activities related to land development on a large scale are continually altering the habitat of the olive darter. [9] Currently P. squamata is a vulnerable species with a rank of 1 meaning that its vulnerability is caused by present or threatened destruction, modification, or reduction of a taxon's habitat or range. [10] Streams are a very dynamic ecosystem that can be thrown off by even the slightest change to its environment. Humans are largely and almost fully to blame for the increasing loss of the olive darter. The lacks of Best Management Practices as well as construction of dams, road crossings and weirs are anthropogenic barriers [11] that are leading to the destruction of stream habitats. The presence of these barriers causes stream fragmentation and loss of the natural flow of the stream. The stream above the dam oftentimes becomes a lake and is quickly sediment, while the streams below the dam become dry stream beds. [12] If below the dam doesn't become a dry stream bed, chances are that it will become genetically isolated as well as cut off from spawning grounds, food, protection and required water flow velocity. Though not human caused, olive darter habitat is also becoming threatened due to the hemlock woolly adelgid. [3] Hemlocks are a shade tolerant species that usually grow in moist areas, such as along streamside riparian zones. The adelgid kills a vast amount of Eastern hemlock trees (Tsuga canadensis) leading to siltation.
The snail 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 found in East Tennessee freshwater in the United States and in small portions of northern Alabama and Georgia. First recorded in 1973, the snail darter was listed as endangered under the U.S. Endangered Species Act of 1973 by 1975. The species was at the center of a major environmental law controversy that involved a lawsuit seeking to halt the completion of Tellico Dam, which posed a risk of extinction for the snail darter by blocking its migratory route. The case was eventually appealed to the U.S. Supreme Court, which ruled on it in its 1978 decision Tennessee Valley Authority v. Hill.
The leopard 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 native to the United States, where it can be found only in the Little River drainage in Oklahoma and Arkansas. Its typical habitat is medium to large streams with rubble and boulder substrate. It feeds on small invertebrates on the riverbed and spawns mainly in March and April. It is threatened by impoundment, habitat loss and runoff from agricultural activities. It has never been a common species and has been listed as a threatened species in the United States since 1978, and the International Union for Conservation of Nature lists it as a "vulnerable species".
The tangerine darter or river slick 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 found in the eastern United States. It grows to a length of 4.3 to 7.1 inches, males being bright orange-red while females are yellow. It is insectivorous, picking insect larvae off aquatic plants and the riverbed, and sometimes rolling small stones over to expose prey. It breeds in late spring and early summer, typically in shallow sandy or gravelly riffles. Pollution and habitat degradation may be a problem in parts of its range, however it is a fairly common fish with a wide range and the International Union for Conservation of Nature has classified its conservation status as being of "least concern".
The common logperch, sometimes simply known as the logperch, 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. Like other logperches, it has the typical vertical barring along the flank and a subterminal mouth.
The ashy 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 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 dusky 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, but not confined to, both large and small rivers, and shallow creeks, in the eastern, southern, and southeastern United States, particularly the Mississippi River drainage system.
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 bluebreast 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 endemic to the eastern United States from New York and Illinois to Tennessee and North Carolina.
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 gilt 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 can be found in a number of states in the Mississippi River drainage of the United States although it has been extirpated from some river systems in which it was at one time present, mostly due to siltation and pollution problems. Males are more colorful than females and can grow to a length of about 9 cm (3.5 in). It is a benthic fish that feeds primarily on small aquatic insect larvae. Males form territories during the breeding season in late spring and early summer. Spawning typically takes place at the upper ends of riffles with sandy and gravelly bottoms interspersed with larger cobbles. Some organisations are endeavouring to conserve populations of the gilt darter and re-introduce it to states where the fish has been extirpated but suitable habitat still exists.
The Mobile logperch 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 Mobile River basin in Mississippi, Alabama, Tennessee, and Georgia in the southeastern United States. It inhabits clear shallow water and is often associated with Podostemum (riverweed). It grows to about 18 cm (7 in) and is distinguishable from other darters by the distinctive shape of its head and by its pale-yellow base color, with narrow bars on back and sides. It feeds on small invertebrates and breeds between February and May. Lake fish move into small streams to spawn. It is a common fish with a wide range and the International Union for Conservation of Nature has classified its conservation status as being of "least concern".
The blackbanded 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 native to the river systems of the southeastern United States where it is found in the states of Tennessee, Georgia, Florida, Mississippi, Alabama, and Louisiana. It lives over sandy or gravelly bottoms in smaller rivers and streams and its color varies depending on the different habitats in which it lives. It feeds on small insect larvae and is itself preyed on by larger fish. It spawns between February and June depending on locality. It is generally a common fish throughout most of its range.
The bronze 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 restricted to the Coosa and Tallapoosa River systems in Georgia, Alabama, and southeastern Tennessee in the United States. It feeds on insect larvae and other small invertebrates, and spawns in April and May. It is a common fish within its range and the International Union for Conservation of Nature has classified its conservation status as being of "least concern". However, it is susceptible to environmental disturbance and an ongoing management plan has been put in place to protect its habitat.
The frecklebelly 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 primarily occurs in the upper Kentucky and Green river systems of eastern and central Kentucky and north-central Tennessee, being found mostly in the Cumberland Plateau and Highland Rim regions. The fish gets its name from gets its name from the scattered dark spots on its relatively pale underside. However, a possible more telling characteristic of the species is the systematical arrangement of the spots at the base of the tail as well as the continuous stripes down either side of the back. Total population size is unknown but figured to be relatively large. The frecklebelly darter is a benthic darter that relies on invertebrates as its principal diet. The frecklebelly darter can be found primarily in creeks and small rivers with a moderate gradient and a pool/riffle type flow, and spends most of its time in midwater areas of the stream. The major threats of the frecklebelly darter include decimation through perturbations such as strip mining as well as stream channelization projects. The darter is thought to have a high resilience with minimum population doubling time less than 15 months; it is also believed to have low vulnerability. Frecklebelly darter females contain about 100-300 mature ova depending on size. Fish become mature by age 1. Spawning in this darter species involves egg burial where the male mounts the female and deposits eggs in deep depressions created by receptive females.
The saddleback 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 native to the eastern United States. This darter species is widespread, occurring from the Escambia River drainage west to the Mississippi River basin and as far north as the Wabash River historically. Some populations have been reported in the Tennessee River drainage. The saddleback darter is aptly named as it has 5 saddle-like patterns on its dorsum, with the first occurring near the first dorsal fin and the fifth near the caudal penduncle. Adults can attain a maximum size of about 3 inches or 7.8 centimeters. The saddleback darter typically occurs over sand and gravel runs of creeks and small to medium-sized rivers and is sometimes found in very shallow water. This darter's diet consists of invertebrates such as caddisfly larvae, beetles, mayflies, and stoneflies. The saddleback darter deposits eggs over sand and gravel shoals during the spring. This species has an average lifespan between 2 and 3 years.
The sickle darter is a recently identified 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 closely related to a well-known darter, Percina macrocephala. Discovered in 2007 in the upper Tennessee River drainage, the sickle darter is around 90.5 mm (3.56 in) in length and is a slender bodied, freshwater and benthopelagic fish that most likely feeds on small crayfish and mayflies, since it shares a large mouth and long snout with its sister species. The known distribution of the sickle darter is the upper drainage of the Tennessee River of Tennessee, North Carolina and Virginia. It is distinguished from all other Percina darters except its sister species P. macrocephala by a dark suborbital bar and a black bar subtending a medial black spot on the base of the caudal fin. It stays in mostly rocky, sandy, or silty substrates in clear creeks or small rivers in the Appalachian Mountains. The sickle darter spawns in late winter in gravel shoals. It also has large scales which make it different from macrocephala. It's known to be extirpated from most of its home habitat mainly because of agricultural practices that cause siltation and turbidity which causes most populations of the sickle darter to be widely scattered. But where it is found, it can be observed with regularity. Taking all this into consideration, the sickle darter does not have a formal conservation status under any federal or state law although its closely related species is considered a species of concern by the TWRA. Future management plans should include finding more locations of the sickle darter and decreasing further habitat destruction in known distributions by stating it as a fish of concern by state law.
The Halloween darter is a small freshwater fish native to North America. It is found in Georgia and Alabama in the drainage basin of the Apalachicola River, specifically in the Flint River system and the Chattahoochee River system. It prefers shallow, fast-flowing areas with gravel bottoms in small and medium-sized rivers. It was first described in 2008, having not previously been distinguished from the Blackbanded darter (P. nigrofasciata), formerly though to occur in the same watershed. Blackbanded darter has since been split again with Westfall's darter now recognised from the Apalachicola drainage. The species is somewhat variable, being generally blackish dorsally, with some individuals having indistinct saddle-like barring. Males have orange and dark lateral striping while females have dark stripes and a yellowish-green belly. At a maximum standard length of 101 mm (4 in), males are slightly larger than females, and both sexes develop distinctive orange barring on the edge of the first dorsal fin during the breeding season.