{{Short description|Species of fish}} {{Speciesbox | status = CR | status_system = IUCN3.1 | status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=NatureServe |year=2013 |title=''Gila elegans'' |errata=2020 |article-number=e.T9186A174778584 |doi=10.2305/IUCN.UK.2013-1.RLTS.T9186A174778584.en |access-date=12 November 2021}}</ref> | image = Bonytail chub or bonytail, Gila elegans.jpg | taxon = Gila elegans | authority = S. F. Baird & Girard, 1853 }}
The '''bonytail chub''' or '''bonytail''' ('''''Gila elegans''''') is a species of freshwater ray-finned fish belonging to the family Leuciscidae, which includes the daces, chubs, Eurasian minnows, and related species. This fish is native to the Colorado River Basin of Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming in the Southwestern United States;<ref name=fishbase>{{FishBase|Gila|elegans|month=February|year=2017}}</ref> it has been extirpated from the part of the basin in Mexico.<ref name="iucn status 12 November 2021" /> It was once abundant and widespread in the basin, its numbers and range have declined to where it has been listed as endangered since 1980 (Endangered Species Act of 1973) and 1986 (IUCN),<ref name="iucn status 12 November 2021" /><ref name=ECOS>{{cite web | title = Bonytail chub (Gila elegans) | url = https://ecos.fws.gov/ecp0/profile/speciesProfile?spcode=E020 | publisher = US Fish and Wildlife Service | access-date = 26 February 2017 }}</ref> a fate shared by the other large Colorado basin endemic fish species such as the Colorado pikeminnow, humpback chub, and razorback sucker. It is now the rarest of the endemic big-river fishes of the Colorado River. Twenty species are in the genus ''Gila'',<ref>{{FishBase genus|genus=Gila|month=February|year=2017}}</ref> seven of which are found in Arizona.
==Description==
A bonytail chub can grow to {{cvt|62|cm|ft|0}} long.<ref name=fishbase/> Like many other desert fishes, its coloring tends to be darker above and lighter below, serving as a camouflage. Breeding males have red fin bases. They have a streamlined body and a terminal mouth.<ref name="desertmuseum">{{cite book | editor = Steven J. Phillips | editor2 = Patricia Wentworth Comus | title = A Natural History of the Sonoran Desert | publisher = University of California Press | date = 2000 | pages = [https://archive.org/details/naturalhistoryof00ariz/page/514 514] | isbn = 0-520-21980-5 | url = https://archive.org/details/naturalhistoryof00ariz/page/514 }}</ref> Bonytail chubs have bodies that sometimes arch into a smooth, predorsal hump (in adults). While their skull is quite concave, their caudal peduncle (tailside) is thin and almost looks like a pencil (hence, "bony tail"). The coloration of bonytail chubs is usually dark dorsally and lighter ventrally, but in very clear waters, they look almost black all over.<ref name="Minckley, W.L 1973. pp. 95–96">Minckley, W.L. 1973. Fishes of Arizona. Arizona Game and Fish Department, Phoenix. pp. 95–96.</ref> During breeding season, males and females have distinct coloration, as well. Mature males have bright red-orange lateral bands between their paired fins, while females have a more subdued coloration that is described with the males.
thumb|Bonytail chub at OdySea Aquarium.
==Range and status==
The bonytail chub was once found in the Colorado River basin in many U.S. states, including Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming.<ref name=fishbase/> It also occurred in the part of the basin in Mexico, but it has been extirpated from this country.<ref name="iucn status 12 November 2021" /> This fish species experienced the most abrupt decline of any of the long-lived fishes native to the main stems of the Colorado River system. No remaining wild population is self-sustaining, and it is functionally extinct.<ref name="iucn status 12 November 2021" /> Its survival currently relies on release of hatchery-produced fish; several hatcheries maintain this species.<ref name=UCREFR>{{cite web| title=Bonytail (Gila elegans) | url= http://www.coloradoriverrecovery.org/general-information/the-fish/bonytail.html | publisher=Upper Colorado River Endangered Fish Ricovery Peogram | access-date=27 February 2017}}</ref> Bonytail chubs were one of the first fish species to reflect the changes that occurred in the Colorado River basin after the construction of Hoover Dam; the fish was extirpated from the lower basin between 1926 and 1950.<ref name="status">Mac, M. J., Opler, P. A., Haecker, C. E. P. and Doran, P. D., editors. 1998. Status and Trends of the Nation's Biological Resources - Southwest. United States Geological Survey, Biological Resources Division, 986 pp.</ref> They may still be found in the Green River of Utah and perhaps in the larger Colorado River water bodies.<ref name="desertmuseum"/> ''Gila elegans'' was added to the US list of endangered species on April 23, 1980<ref name=ECOS/> and was first recognized as endangered in 1986 by IUCN.<ref name="iucn status 12 November 2021" /> In 2013, its IUCN status was upgraded to critically endangered.<ref name="iucn status 12 November 2021" />
Reintroduction of the bonytail chub is contentious.<ref>(18 January 2007) "Editorial: Fish to Fry" ''The Pueblo Chieftain'' Pueblo, Colorado</ref> Some are concerned about the amount of water used to increase stream flows that are required for adequate bonytail chub habitat.<ref>Baird, Joe (20 January 2006) "Uintah County seeks money for possible lawsuit against feds" ''The Salt Lake Tribune'' Salt Lake City. Utah. p. B-2</ref> Bass fishermen are concerned about facilitating the recovery of the bonytail chub by the removal of smallmouth bass, a popular gamefish.<ref>Staff (3 May 2007) "Group works to control smallmouth bass, pike" ''Deseret Morning News'' Salt Lake City, Utah</ref> Fears of spreading the quagga mussel, an invasive species that clogs water pipelines and fouls marine equipment, has halted the reintroduction of the bonytail chub in Arizona, pending establishment of a stocking protocol that is satisfactory to Arizona wildlife officials.<ref>Rogers, Keith (17 February 2007) "Stocking of trout resumes at lakes" ''Las Vegas Review-Journal'' Las Vegas, Nevada, p. 2B</ref>
==Habitat==
Bonytail chub prefer backwaters with rocky or muddy bottoms and flowing pools, although they have been reported in swiftly moving water. They are mostly restricted to rocky canyons today, but were historically abundant in the wide downstream sections of rivers.<ref name="desertmuseum"/>
==Biology==
Young bonytail chubs typically eat aquatic plants, while adults feed mostly on small fish, algae, plant debris, and terrestrial insects.<ref name="desertmuseum"/>
Bonytail chubs are long-lived and may reach an age of up to 50 years.<ref name=UCREFR/>
=== Reproduction ===
Little is known about their reproductive habits, but they are thought to spawn in midsummer and perhaps hybridize with both roundtail and humpback chubs.<ref name="desertmuseum"/> Spawning in Lake Mohave has been observed during May, while in the upper Green River, it occurs in June and July.<ref name="Minckley, W.L 1973. pp. 95–96"/> Eggs are laid randomly over the bottom, and no parental care occurs.
== Conservation ==
The bonytail chub's population sizes are small and declining. The depletion of the population is primarily due to the habitat alterations caused by dams and competition and predation by non-native fish.<ref>Bestgen, K.R., Zelasko, K.A., Compton, R.I., Chart, T.E. Survival, Condition, Habitat Use, and Predation on Stocked Bonytails (Gila elegans) in the Green River, Colorado and Utah. ''The Southwestern Naturalist'' 53(4):488-494. 2008.</ref>
A USFWS Recovery Plan established in 1990 included the objectives of protecting the habitats of the bonytail chub, and even reintroducing hatchery-reared fish into the wild.<ref>Bagley, B.E. 1989. Nongame field note: Bonytail Chub. Arizona Game and Fish Department, Phoenix. pp. 1–3.</ref>
The Bonytail Chub Recovery Plan was approved on September 4, 1990, and refugia for the bonytail chub exist today in several places: Dexter National Fish Hatchery, New Mexico; Arizona Game and Fish Page Springs Hatchery; Ouray National Wildlife Refuge, Ouray, Utah; Buenos Aires National Wildlife Refuge, Sasabe, Arizona; and Niland Native Fish Ponds, California.
==References== {{Reflist}}
==External links== * [http://ecos.fws.gov/speciesProfile/SpeciesReport.do;jsessionid=F114D9286D23D0BE373A60A6ADD9F1E9?spcode=E020 ''Gila elegans'' Species Profile], U.S. Fish & Wildlife Service (Accessed 2007 Mar 04) *[http://ecos.fws.gov/docs/life_histories/E020.html USFWS Environmental Conservation Online System page for Bonytail chub] * [http://www.fws.gov/coloradoriverrecovery USFWS Upper Colorado Endangered Fish Recovery Program] *[http://ecos.fws.gov/tess_public/SpeciesReport.do?groups=E&listingType=L&mapstatus=1 USFWS List of Fish Listed under Endangered Species Act]
{{Taxonbar|from=Q3756661}} {{Authority control}}
{{DEFAULTSORT:Bonytail Chub}} Category:Chubs (fish) Category:Gila (fish) Category:Taxa named by Spencer Fullerton Baird Category:Taxa named by Charles Frédéric Girard Category:Fish described in 1853 Chub Category:Fish of North America Category:ESA endangered species Category:Freshwater fish of North America