Bluemask darter

Bluemask darter
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Family:	Percidae
Genus:	Etheostoma
Species:	E. akatulo
Binomial name
Etheostoma akatulo Layman & Mayden, 2009

The common name of Etheostoma akatulo is the bluemask darter. It is one of the 324 fish species found in Tennessee. 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.

Description

This Wikipedia article is a monitoring plan for Etheostoma akatulo. It is a guide of the current status of Etheostoma akatulo and the future recommended plans for Etheostoma akatulo. The common name of Etheostoma akatulo is the Bluemask Darter. The species differs from other species of the subgenus Doration by having fully scaled cheeks, complete lateral line, breeding males with bright blue pigment completely covering the lower face, and breeding males with soft dorsal and anal fins lacking orange and blue pigment. This article will discuss the geographic distribution of Etheostoma akatulo which is found from the upper Caney Fork River System of the middle Cumberland River drainage, Tennessee. It is presently known from four tributaries of Great Falls Reservoir on the eastern Highland Rim and is listed as federally endangered. It will also talk about the ecology of the species, such as which habitats it lives in, its predators, and which species it competes with. Next, it will discuss the Life history of Etheostoma akatulo, when it breeds and how often does it breed. Then, the current management plan will be discussed. Some of the reasons for the decline in the species is due to habitat destruction, agricultural runoff, and siltation. So the current management plans will revolve around these major factors and how to prevent further damage. Finally, the article will discuss future plans for the management of the species.

Geographic Distribution of Species

Etheostoma akatulo is known from five small rivers and large creeks of the upper Caney Fork River system, Tennessee, including Collins River, Rocky River, Calfkiller River, Cane Creek, and upper Caney Fork River. Etheostoma akatulo is most abundant and widely distributed in Collins River, where it occurs in a 37-km reach between Shellsford, Warren Co., and Tennessee Highway 56, 1.2 km east of Mt. Olive, Grundy Co. In Rocky River, the species inhabits only a 4.3-km reach from Tennessee Highway 30 upstream to Laurelburg Road ford, Van Buren Co., including a 1.7-km reach that alternates between backwater and free-flowing conditions as Great Falls Reservoir fluctuates between maximum (244 m) and minimum (240 m) pool elevations. In Cane Creek, recent collections are from the lower 200 m of free-flowing waters in Van Buren Co. In upper Caney Fork River, the species has been collected in an intermittent reach located only 1.8 river km upstream of reservoir maximum pool in White Co. The species also possibly uses portions of the reservoir fluctuation zones in Cane Creek and Caney Fork River, depending on the occurrence of sufficient current velocities or spring inflow to moderate silt deposition. Etheostoma akatulo is restricted in distribution to the Caney Fork River system in free-flowing streams upstream of Great Falls. All four extant populations apparently are isolated from one another by the impounded waters of Great Falls Reservoir.

Ecology

Not much is known about the ecology of Etheostoma akatulo. It is believed that because it is a darter it has a similar diet to most darters. Darters, as their name implies, dart about on the bottoms of streams and eat small crustaceans and insects. Etheostoma akatulo occurs in slow to moderate current over sand and fine gravel at depths of 10–50 cm, typically just downstream of riffles, in runs, or along margins of pools. During spawning Etheostoma akatulo males and females have been seen occupying different microhabitats. Substrate dominated by gravel was occupied by lone males and spawning pairs, whereas most lone females were found over a sand-dominant substrate. After the spawning period, Bluemask Darters move to sandy substrates in low-velocity areas of intermediate depth. Much more research is needed to know the full ecology of this endangered fish. It was only formally described in 2009 so not much is known to date.

Life History

Very little information is known on the life history of Etheostoma akatulo. Many scientific papers compare the life history of Etheostoma akatulo to Etheostoma stigmaeum. Etheostoma akatulo, before it was formally described, was once considered a subspecies of Etheostoma stigmaeum. E. stigmaeum is known to lay its eggs in gravelly areas and after they have been laid, it covers them with the gravel. Etheostoma akatulo is believed to demonstrate the same egg laying behavior. E. akatulo can live to be 39 months old. They show the highest amount of growth during the first year of life but do not reach sexual maturity until year two. There are several human problems affecting the life history of this fish. Agricultural runoff and gravel dredging are significantly hurting the reproductive effort of the fish. Gravel dredging destroys the spawning sites for the species and can lead to a decline in the species.

Current Management

Etheostoma akatulo was listed as a federally endangered species in 1993. Existing and potential threats to continued survival of the species include habitat destruction from gravel dredging, which has already eliminated habitat once occupied by the species in Collins River; pesticides in runoff or groundwater from plant nurseries; siltation from gravel mining, agricultural runoff, or land-disturbing activities; and acid mine drainage from headwater streams. The most significant factor contributing to the bluemask darter's decline was likely the building of the Great Falls Dam. The reservoir impounded by the dam flooded over 80 kilometers of possible bluemask darter habitat and isolated the tributary populations from each other. Because of the isolation, the genetic viability over a long period of time is questionable for the species. One of the current plans for managment is the reintroduction of Etheostoma akatulo to the Calfkiller River. Because of gravel dredging the substrate in Calfkiller River is not ideal so first they are making new sand and gravel substrates. Then, the reintroduction of the fish will begin.

Management Recommendations

To save the bluemask darter, all existing State and Federal legislation and regulations must be enforced. Bluemask darter research needs include: life history information ; propagation and reintroduction techniques, and genetic diversity of populations. Management needs include: feasibility of reintroducing the species into Calfkiller River; promoting the safe use of pesticides; enforcing existing Federal and State laws relating to water quality and gravel dredging, and monitoring populations. Additionally, management is needed to restore some of the species' habitat through repair of riparian habitat and control of nonpoint source pollution.

References

Simmons Jeffrey W.; Layzer James B.; Smith David D.(2008). Age-class Structure and Variability of Two Populations of the Bluemask Darter Etheostoma (Doration) sp. American Midland Naturalist Volume: 160 Issue: 2 Pages: 300-309.

Simmons Jeffrey W.; Layzer James B.(2004). Spawning behavior and habitat of the endangered bluemask darter, Etheostoma (Doration) sp. Copeia Volume: 2004 Issue: 2 Pages: 412-417.

Layman Steven R.; Simons Andrew M.; Wood Robert M.(1993). Status of the dirty darter, Etheostoma olivaceum and bluemask darter, Etheostoma (Doration) sp., with notes on fishes of the Caney Fork River System, Tennessee. Journal of the Tennessee Academy of Science Volume: 68 Issue: 2 Pages: 65-70.

Layzer James B.; Brady Tony R.(2003). Summer microhabitat of the endangered bluemask darter Etheostoma (Doration) sp. Journal of the Tennessee Academy of Science Volume: 78 Issue: 2 Pages: 55-57.

Simmons, J W; Layzer, J B.(2003). Reproductive ecology of the endangered bluemask darter, Etheostoma [Doration] sp. Southeastern Biology, 50(2): p. 160

http://www.fws.gov/cookeville/docs/bluemask.htm

http://www.fws.gov/cookeville/docs/endspec/blmdrtsa.html

External links

• http://www.bio.utk.edu/hulseylab/Fishlist.html