|
The laurel dace (''Chrosomus saylori'') is a species of freshwater minnow native to the U.S. state of Tennessee. It was first discovered in 1976.〔''Chrosomus saylori'', Laurel Dace. Fishbase. 2010. 18 November 2011. http://www.fishbase.org/summary/Phoxinus-saylori.html.〕 A very rare species, it has only been found in localized populations in six small streams on the Walden Ridge portion of the Cumberland Plateau in Tennessee.〔Starnes, W. C., and R. E. Jenkins. 1988. A new cyprinid fish of the genus ''Phoxinus'' (Pisces: Cypriniformes) from the Tennessee River drainage with comments on relationships and biogeography. Proc. Biol. Soc. Wash. 101:517–529.〕 It is found in six streams: the Soddy, Horn, Cupp, Young's, Moccasin, and Bumbee Creeks, all of which drain into larger rivers that eventually feed the Tennessee River.〔 It is believed to be extirpated from Laurel Creek, the only other stream where it was known to occur.〔 It is commonly considered a nest associate and uses its large mouth and short intestinal tract to support an animal-based diet. Displaying sexual dimorphism, an average adult ''C. saylori'' measures approximately 45 mm at the age of reproduction.〔Skelton, C. E. 2001. New dace of the genus ''Phoxinus'' (Cyprinidae: Cypriniformes) from the Tennessee River Drainage, Tennessee. Copeia 2001:118–128.〕 Similar to other ''Chrosomus'' species, two dark parallel lines run the length of the body, and a red coloration appears during the breeding season. Spawning is believed to take place in small, cool streams, lined with small pebbles.〔Raney, E. C. 1947. ''Nocomis'' nests used by other breeding cyprinid fishes in Virginia. Zoologica 32:125– 132.〕 As of August 9, 2011, this species was placed on the endangered species list, as a result of agriculture, mining, and timbering in the Walden Creek area.〔Species Profile for Laurel Dace (''Phoxinus saylori''). U.S. Fish and Wildlife Service. 21 November 2011. The fish is named for ichthyologist Charles F. Saylor, who was one of the first to collect it. Its common name refers to mountain laurel (''Kalmia'' spp.), which is a common plant next to the streams where it lives.〔 ==Description== This minnow is 45.7 millimeters long on average. It is olive green to tan in color with a silvery white underside. It has two black stripes on each side. During the breeding season the fish changes color, developing bright red coloration on the lower parts. Part of the dorsal fin becomes red, as do the lips. The stripes become a deeper black and there are more black areas on the head and breast. The cheeks and the area between the black stripes become gold. Most of the fins turn yellow. Females and males both change colors, but the male's colors are more intense. Otherwise, female and male can be told apart by the shape of the pectoral fins.〔Skelton, C. E. (2001). (New dace of the genus ''Phoxinus'' (Cyprinidae: Cypriniformes) from the Tennessee River drainage, Tennessee. ) ''Copeia''〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Laurel dace」の詳細全文を読む スポンサード リンク
|