Slackwater darter
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| Etheostoma boschungi Wall and Williams, 1974 |
The slackwater darter, (Etheostoma boschungi) is a small fish of the stippled darter group. The slackwater darter has a conspicuous dark subocular bar and three prominent saddles. It is rather drab in color, the dorsum being dusky, olivaceous, or brownish. The lateral blotches are dark brown to blue-black. The venter is slightly dusky and may have some orange and yellow pigments, which are more intense in males than in females. Maximum size is approximately 55 millimeters standard length.
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[edit] Reproduction
The reproductive behavior of the slackwater darter varies with the temperature of the breeding habitat and the amount of rainfall. Spawning has not been recorded in water less than 14 °C. In addition, heavy rainfall must cause enough flooding to lift the darters into the breeding area (U.S. Fish and Wildlife Service 1984). Usually, adult darters begin their migration to the breeding area in mid-January. They reach the breeding habitat in February, and spawning occurs in March. By April, the darter progeny are developing, and will leave the breeding area in May (Boschung 1976). Young darters double in size between April and June. Evidence suggests that the slackwater darter is a short-lived species with a life span of only 3 years.
[edit] Range and population level
The geographic range of the slackwater darter is five tributaries to the southern bend of the Tennessee River in northern Alabama and southwestern Tennessee. The species is known from: one locality in the headwaters of the Buffalo River in Lawrence County, Tennessee; 19 localities in the Cypress Creek drainage in Wayne County, Tennessee, and Lauderdale County, Alabama; three localities in Swan Creek, Limestone County, Alabama; three localities in the Flint River drainage in Madison County, Alabama; and, one specimen was found in Shoal Creek, Lawrence County, Tennessee (U.S. Fish and Wildlife Service 1984). Nothing is known of this darter's past distribution and abundance.
Periodic sampling in the headwaters of the Buffalo River in Lawrence County, Tennessee, has indicated that its population of slackwater darters is extremely small and limited. In this area the species is confined to a short segment of a very small stream, and the number of individuals is apparently quite low. The population in the Flint River drainage in Madison County, Alabama, is similarly small and limited. The largest population and the stronghold of the species is in the Cypress Creek drainage system, Wayne County, Tennessee, and Lauderdale County, Alabama.
[edit] Habitat
The slackwater darter uses two different, but adjacent, breeding and nonbreeding habitats. Its nonbreeding habitat is small to moderately large streams with a moderate to slow current. The slackwater darter seems to prefer bottom conditions characterized by an accumulation of leaves and detritus, but in some areas it has been found in association with clean silt, sand, and small gravel substrates. Breeding habitat is seepage water in open fields or woods. The water in the breeding area, about 4 to 8 centimeters deep, flows slowly into an adjacent stream (the nonbreeding habitat). Since the breeding habitat is usually 30 to 45 centimeters above the stream, the stream water must periodically rise (as it does during heavy rains) to give darters access to the breeding grounds (U.S. Fish and Wildlife Service 1984)
CRITICAL HABITAT: Alabama, Lauderdale County: All permanent and intermittent streams with flowing water from December to June; tributary to Cypress Creek and its tributaries upstream from the junction of Burcham Creek, including Burcham Creek, excluding Threet Creek and its tributaries. Tennessee. Wayne County. All permanent and intermittent streams with flowing water from December to June, tributary to Cypress and Middle Cypress Creek drainage. Lawrence County, Buffalo River and its tributaries.
[edit] Threatened species
The restricted range of this species increases its vulnerability to the detrimental effects of human activity. Urbanization, ditching to drain areas with shallow groundwater, and degradation of ground and surface water from pesticides and waste are all serious threats. For example, the population in the Flint River drainage in Madison County, Alabama, is threatened by changing land use patterns associated with the growth of the city of Huntsville, Alabama.
This species' existence is dependent upon adjacent and suitable breeding and nonbreeding habitats. If either of these habitats becomes unsuitable, darters will be extirpated from that location. A declining ground water table has eliminated darter breeding sites in some areas. Slackwater darter breeding areas are also potential sites for farm fish ponds, which would innundate the habitat.
[edit] Management and protection
The future well-being of the slackwater darter will depend upon wise use of the land and the general adoption of policies which will assure preservation of essential habitat needs. This species' recovery plan, approved in 1984, provides the following guidelines for its recovery: (1) establishment and protection of one or more specific habitat areas in at least three different tributaries to the Tennessee River System, with spawning areas protected by purchase or cooperative agreement; (2) data to show that populations are stable or increasing; and, (3) water quality and ecological data to indicate that the environment is suitable and stable or improving.
The above goals will be achieved by researching and providing this fish's survival needs. Some strategies, listed in the recovery plan, include: 3- to 5-year censuses near and in selected breeding habitats to determine and monitor populations; analyses of water quality and other characteristics in breeding and nonbreeding habitats; and research on the darter's reproductive and life cycles. The U.S. Fish and Wildlife Service is also continuing to coordinate with the Soil Conservation Service to protect slackwater darter habitat in the Cypress Creek drainage, Tennessee.
[edit] References
Note: This article was adapted from a public domain Fish and Wildlife Service report.
- Gimenez Dixon (1996). Etheostoma boschungi. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Listed as Endangered (EN B1+2c v2.3)
- Etheostoma boschungi (TSN 168377). Integrated Taxonomic Information System. Accessed on 19 March 2006.
- "Etheostoma boschungi". FishBase. Ed. Ranier Froese and Daniel Pauly. November 2005 version. N.p.: FishBase, 2005.
- Fish and Wildlife Service report
- Boschung, Herbert, and T.S. Jandebeur. 1974. A Report on the Fauna of the Cypress Creek Watershed, With Emphasis on Fishes. Unpublished Report for the Soil Conservation Service, U.S. Department of Agriculture. The University of Alabama, University, Alabama. 165 pp.
- Boschung, Herbert. 1976. An Evaluation Of The Slackwater Darter, Etheostoma boschungi, Relative To Its Range, Critical Habitat, and Reproductive Habitat In The Cypress Creek Watershed And Adjacent Stream Systems. U.S.D.A. Soil Conservation Service, Auburn, Alabama. 5O pp.
- Federal Register, Vol. 42, No. 175. September 9, 1977.
- U.S. Fish and Wildlife Service. 1984. Recovery Plan for The Slackwater Darter (Etheostoma Boschungi). Prepared by Herbert Boschung, University of Alabama for U.S. Fish and Wildlife Service, Atlanta Georgia. 45 pp.
- Wall, Benjamin R. and J.S. Williams. 1974. Etheostoma boschungi, A New Percid Fish From the Tennessee River Drainage in Northern Alabama and Western Tennessee. Tulane Stud. Zool. and Bot. 18(4): 172-182.
