These pages have been organized according to the family classification. You will find links to this page from all of the NFH home pages and from a main index page . Markings on this yellowish fish include a faint lateral stripe, which is the most pronounced mark on the body. It has orange and yellow dorsal and anal fins, a bar beneath the eye, and a faint, dark chin bar.
Males are smaller than females.
It was listed as endangered by the U.S. Fish and Wildlife Service on March 11, 1967. Its natural habitat was clear, shallow pools and runs fed by warm springs. At the present time, it is restricted to two small, spring-fed pools and runs near Rio Grande Village in Big Bend National Park in Brewster County, Texas. Historically, it was found in at least four U.S. and one Mexico spring tributary of the Rio Grande in the Big Bend area. It declined due to habitat alteration, declining water supplies, and competition with the introduced mosquitofish.