What is "bonytail chub"

The bonytail chub or bonytail, Gila elegans, is a cyprinid freshwater fish native to the Colorado River of Arizona, California, Colorado, Nevada and Utah in the southwestern United States. It was once abundant and widespread in the basin, its numbers and range have declined to the point where it has been listed as endangered (1980), a fate shared by the three other large Colorado basin endemic fish species: Colorado pikeminnow, Humpback chub, and Razorback sucker. It is now the rarest of the endemic big-river fishes of the Colorado River. There are 14 species of the genus, 7 of which are in Arizona.