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Holiday darter
The holiday darter (''Etheostoma brevirostrum'') is found in the southeast US water system, with disjunctive populations throughout Alabama, Georgia, and Tennessee. It is also located in the Coosa River watershed which begins in Tennessee and Georgia, then enters Alabama. Its diet, close to other members of the subgenus ''Ulocentra'', consists of small insects, including midges, black fly larvae, and small crustaceans. The two subspecies inhabit small to medium-sized gradient-rich streams. They are often found in fast-moving streams with large boulders, gravel, cobbles, and sand. They can be found in the margins between these large boulders, and use the boulders for protection from predators and for the females to attach eggs. The holiday darter has very vibrant coloration, but will display even more brilliant coloration during or before spawning. Spawning takes place during the spring, usually around April or May. This species is state listed in Georgia as threatened. One of the disjunct populations is located in the Talladega National Forest, which results in it being protected from human encroachment. The separate populations can make it difficult to determine the exact population count.
==Distribution==
The distribution of ''E. brevirostrum'', according to the US Fish and Wildlife Service, is known or believed to be in Alabama, Georgia, and Tennessee, including the Consauga River and the upper Coosa River system. It is only known to populate four different river systems, at about 18 different locations. It is believed to be extirpated in portions of its current range, and to have a stable population in the Upper Shoal Creek, and the Consauga River from Murray County, Georgia, to Polk County, Tennessee. It is “possibly extirpated from the Calhoun County, Alabama, section of Shoal Creek due to impoundments.”〔Johnston, C.E. and K.B. Damon. 1996. Long term monitoring of rare fishes in the consauga river, Georgia and Tennessee. Unpublished report to the USDA forest service, southern research station, Oxford Mississippi. 11+ pp.〕 This darter is highly affected by barriers that prevent movement throughout a water system. Population counts are spotty and have a wide range of results. Snorkeling has been a common method to take population counts. In the past, population counts at a single site have “resulted in 1, 15-36, 3-13 and 4-10 individuals.” These inconsistent counts make it difficult to determine an exact population counts.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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