Bonytail chub
Encyclopedia
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 in Arizona.
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. 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, however, in very clear waters, they looks almost black all over. 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.
, California
, Colorado
, New Mexico
, Utah
, and Wyoming
. 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 and, because no young individuals have been found in recent years, has been called functionally extinct. 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. They may still be found in the Green River
of Utah and perhaps in the larger Colorado River
water bodies. Gila elegans was added to the US list of endangered species on April 23, 1980.
There is contention about the reintroduction of the bonytail chub. Some are concerned about the amount of water used to increase stream flows that are required for adequate bonytail chub habitat. Bass fishermen are concerned about facilitating the recovery of the bonytail chub by the removal of smallmouth bass
, a popular gamefish. 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.
A USFWS Recovery Plan was established in 1990, and included objectives of protecting the habitats of the Bonytail Chub, and even reintroducing hatchery-reared fish into the wild.
The Bonytail Chub Recovery Plan was approved on September 4, 1990, and many 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; Niland Native Fish Ponds, California.
Gila (genus)
Gila is a genus of fish belonging to the family Cyprinidae, native to North America and Central America. Species of Gila are collectively referred to as western chubs. The chiselmouth is a close relative...
elegans, is a cyprinid freshwater fish native to the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
of Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
and Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
in the southwestern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. 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
Colorado pikeminnow
The Colorado pikeminnow Ptychocheilus lucius is the largest cyprinid fish of North America and one of the largest in the world, with reports of individuals up to 6 ft long and weighing over 100 pounds...
, Humpback chub
Humpback chub
The humpback chub Gila cypha, is a federally protected fish that lived originally in fast waters of the Colorado River system in the United States. This species takes its name from the prominent hump between the head and dorsal fin, which is thought to direct the flow of water over the body and...
, and Razorback sucker
Razorback sucker
The razorback sucker, Xyrauchen texanus, is an endangered fresh water sucker of rivers in the Colorado River drainage of western North America.-Description:...
. It is now the rarest of the endemic big-river fishes of the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
. There are 14 species of the genus, 7 of which in Arizona.
Description
A bonytail chub can grow to over 2 feet (60 cm) long. Like many other desertDesert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
fishes, its coloring tends to be darker above and lighter below, serving as a camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
. Breeding males have red fin
Fin
A fin is a surface used for stability and/or to produce lift and thrust or to steer while traveling in water, air, or other fluid media, . The first use of the word was for the limbs of fish, but has been extended to include other animal limbs and man-made devices...
bases. They have a streamlined body and a terminal mouth. 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, however, in very clear waters, they looks almost black all over. 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.
Range
The bonytail chub was once found in many states, including ArizonaArizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
, Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, and Wyoming
Wyoming
Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
. This fish species experienced the most abrupt decline of any of the long-lived fishes native to the main-stems of the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
system and, because no young individuals have been found in recent years, has been called functionally extinct. 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
Hoover Dam
Hoover Dam, once known as Boulder Dam, is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the US states of Arizona and Nevada. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President...
; the fish was extirpated from the lower basin between 1926 and 1950. They may still be found in the Green River
Green River (Utah)
The Green River, located in the western United States, is the chief tributary of the Colorado River. The watershed of the river, known as the Green River Basin, covers parts of Wyoming, Utah, and Colorado. The Green River is long, beginning in the Wind River Mountains of Wyoming and flowing...
of Utah and perhaps in the larger Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
water bodies. Gila elegans was added to the US list of endangered species on April 23, 1980.
There is contention about the reintroduction of the bonytail chub. Some are concerned about the amount of water used to increase stream flows that are required for adequate bonytail chub habitat. Bass fishermen are concerned about facilitating the recovery of the bonytail chub by the removal of smallmouth bass
Smallmouth bass
The smallmouth bass is a species of freshwater fish in the sunfish family of the order Perciformes. It is the type species of its genus...
, a popular gamefish. Fears of spreading the quagga mussel
Quagga mussel
The quagga mussel is a subspecies of freshwater mussel, an aquatic bivalve mollusk.It is one of seven Dreissena species and has an average life span of 3 to 5 years....
, 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.
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.Reproduction
Spawning in Lake Mohave has been observed during May, while in the upper Green River, it occurs in the months of June and July. Eggs are laid randomly over the bottom, and no parental care occurs.Biology
Young bonytail chubs typically eat aquatic plants, while adults feed mostly on small fish, algae, plant debris, and terrestrial insects. Little is known about their reproductive habits, but they are thought to spawn in mid-summer and perhaps hybridize with both roundtail and humpback chubs.Conservation
The Bonytail Chub’s population sizes are small, and continue to become even smaller. The depletion of the population is primarily due to the habitat alterations caused by dams.A USFWS Recovery Plan was established in 1990, and included objectives of protecting the habitats of the Bonytail Chub, and even reintroducing hatchery-reared fish into the wild.
The Bonytail Chub Recovery Plan was approved on September 4, 1990, and many 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; Niland Native Fish Ponds, California.
External links
- Gila elegans Species Profile, U.S. Fish & Wildlife Service (Accessed 2007 Mar 04)
- USFWS Environmental Conservation Online System page for Bonytail chub
- USFWS Upper Colorado Endangered Fish Recovery Program
- USFWS List of Fish Listed under Endangered Species Act