Gila nigra
Encyclopedia
The Headwater Chub is a species of fish in the Cyprinidae family.
It is found in Arizona
and New Mexico
.
Similar species include the Humpback Chub
(Gila cypha) and Bonytail Chub
(G. elegans), however, these fish have extremely slender caudal peduncles, smaller eyes, angle along anal fin base continuing above the caudal fin. Large individuals have a hump on their nape, and a depressed head which is absent on the Headwater Chub. Gila Nigra are somewhat trout
-like in appearance, except they lack an adipose fin. Not surprisingly, they are morphologically intermediate between the Roundtail chub
(Gila robusta) and the Gila chub (Gila intermedia).
basin of Arizona
and New Mexico
where they occupy the middle and headwater reaches of middle-sized streams. Populations have been recognized from the mainstream Gila River (above confluence with Mangus Creek) in New Mexico, this includes West, Middle and East forks of the Gila River, along with the San Carlos River (a tributary to the Gila). They are also identified from Ash Creek
(tributary to San Carlos River), Tonto Creek
(tributary to the Salt River
), and Spring Creek
, (tributary of Tonto Creek). In the Verde River
system, they inhabit Upper Fossil Creek
(above the diversion dam), East Verde River and Deadman Creek
.
, they were found in water more than 1.8 m deep with velocities under 0.10 meters per second. Substrates they are associated with include gravel, small boulders, and large in-stream objects. Preferred water temperature ranges of 20-27°C with a minimum temperature around 7°C. Juveniles are associated with shallow, low velocity habitat with overhead cover. In Fossil Creek, Headwater Chub seem to select depths between 0.9-1.5 m and velocities of 0.15 meters per second and are found over sand substrate.
The Headwater Chub are associated with substrates including gravel, small boulders, and large in-stream objects. The preferred water temperature ranges of the Headwater Chub are 20-27°C with a minimum temperature around 7°C. Juvenile Headwater Chub are associated with shallow, low velocity habitat with overhead cover. In Fossil Creek, they seem to select depths between 0.9-1.5 m and velocities of 0.15 mps and are found over sand substrate.
The Headwater Chub life span is 8–10 years. The Headwater Chub grow rapidly but growth is dependent on water temperature. The maximum size of the fish is about 50 cm.
It is found in 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...
and 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...
.
Description
The body of the Headwater Chub is thick and chunky to streamlined but not markedly attenuate. The maximum size of the male fish is about 50 cm females are about 10–18 cm total length. The coloration of the fish is dark olive-gray or brown above, with a silver side, and white below. The longitudinal stripes are often diffuse, and are rarely with dark dorsal-lateral blotches. The caudal peduncle is not pencil-like, its length is less than its head length; the fins are small to moderate in size, sometimes convex, and are rarely curved, with inter-radial membranes of fins variously pigmented. Scales are developed and cover the entire body, with the basal radii variable. There are 73-83 lateral scales, with usually 8 dorsal and anal fin rays, and rarely 7 or 9 fin rays.Similar species include the 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...
(Gila cypha) and Bonytail Chub
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...
(G. elegans), however, these fish have extremely slender caudal peduncles, smaller eyes, angle along anal fin base continuing above the caudal fin. Large individuals have a hump on their nape, and a depressed head which is absent on the Headwater Chub. Gila Nigra are somewhat trout
Trout
Trout is the name for a number of species of freshwater and saltwater fish belonging to the Salmoninae subfamily of the family Salmonidae. Salmon belong to the same family as trout. Most salmon species spend almost all their lives in salt water...
-like in appearance, except they lack an adipose fin. Not surprisingly, they are morphologically intermediate between the Roundtail chub
Roundtail chub
The roundtail chub is a cyprinid fish of the Colorado River drainage, including the Gila River and the Rio Yaqui in western North America, part of the “robusta complex”, which includes the Gila robusta robusta, G.r. grahami, and G.r...
(Gila robusta) and the Gila chub (Gila intermedia).
Range
Headwater Chubs are endemic to the Gila RiverGila River
The Gila River is a tributary of the Colorado River, 650 miles long, in the southwestern states of New Mexico and Arizona.-Description:...
basin 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...
and 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...
where they occupy the middle and headwater reaches of middle-sized streams. Populations have been recognized from the mainstream Gila River (above confluence with Mangus Creek) in New Mexico, this includes West, Middle and East forks of the Gila River, along with the San Carlos River (a tributary to the Gila). They are also identified from Ash Creek
Ash Creek
Ash Creek is located in southeastern Arizona in the Pinaleño Mountain Range, part of Coronado National Forest. The closest city is Safford, about 7 miles away.-External links:**...
(tributary to San Carlos River), Tonto Creek
Tonto Creek
Tonto Creek is a stream located in the Mogollon Rim area of the state of Arizona on the north edge of the Tonto National Forest. The closest town, Payson, is away. Tonto Creek is a stream that flows year round, starting just below the Mogollon Rim, at the northern edge of Tonto National Forest...
(tributary to the Salt River
Salt River (Arizona)
The Salt River is a stream in the U.S. state of Arizona. It is the largest tributary of the Gila River. The river is about long. Its drainage basin is about large. The longest of the Salt River's many tributaries is the Verde River...
), and Spring Creek
Spring Creek
A spring creek is a stream that flows from a spring. Spring Creek may also refer to any of the following specific places:- United States :*Spring Creek Correctional Center, a state prison in Seward, Alaska...
, (tributary of Tonto Creek). In the Verde River
Verde River
The Verde River is the north and northwestern watershed of the Salt River–Verde River Watershed that co-join and enter the Gila River at Phoenix, Arizona, located in the U.S. state of Arizona...
system, they inhabit Upper Fossil Creek
Fossil Creek
Fossil Creek is a perennial river in central Arizona, located near the community of Strawberry. The headwaters of the creek begin at Fossil Springs, a rare and powerful spring in Arizona, which produces upwards of one million gallons of water per hour....
(above the diversion dam), East Verde River and Deadman Creek
Deadman Creek
Deadman Creek is the mainstream creek that becomes the Owens River where Big Springs enters the Deadman Creek channel, "two miles east of the [CalTrans] US395 Crestview maintenance station", near Deadman Summit. The Sierra Crest demarcates the creek's drainage from the drainage of the Middle Fork...
.
Habitat
Adult Headwater Chub occupy cool to warm water in mid- to headwater stretches of mid-sized streams of the Gila River basin. They are associated with deep, near shore pools adjacent to swift riffles and runs, and near obstructions. Cover consists of root wads, boulders, undercut banks, submerged organic debris, or deep water. In Fossil CreekFossil Creek
Fossil Creek is a perennial river in central Arizona, located near the community of Strawberry. The headwaters of the creek begin at Fossil Springs, a rare and powerful spring in Arizona, which produces upwards of one million gallons of water per hour....
, they were found in water more than 1.8 m deep with velocities under 0.10 meters per second. Substrates they are associated with include gravel, small boulders, and large in-stream objects. Preferred water temperature ranges of 20-27°C with a minimum temperature around 7°C. Juveniles are associated with shallow, low velocity habitat with overhead cover. In Fossil Creek, Headwater Chub seem to select depths between 0.9-1.5 m and velocities of 0.15 meters per second and are found over sand substrate.
The Headwater Chub are associated with substrates including gravel, small boulders, and large in-stream objects. The preferred water temperature ranges of the Headwater Chub are 20-27°C with a minimum temperature around 7°C. Juvenile Headwater Chub are associated with shallow, low velocity habitat with overhead cover. In Fossil Creek, they seem to select depths between 0.9-1.5 m and velocities of 0.15 mps and are found over sand substrate.
The Headwater Chub life span is 8–10 years. The Headwater Chub grow rapidly but growth is dependent on water temperature. The maximum size of the fish is about 50 cm.
Population Trends
As with many native fish, reductions in range and numbers are likely the result of habitat loss, as well as competition with, and predation by, non-native fish species.Management Factors
Activities that are known to be detrimental to Headwater Chub populations should be avoided, including dewatering of habitats through re-routing stream water, stream impoundment, channelization, domestic livestock grazing, timber harvesting, mining, road construction, polluting, and stocking non-native fish.- Threats: aquifer pumping; stream diversion; reduction in stream flows; predation by and competition with nonnative fishes.
- Management Needs: watershed and stream flow protection; research to determine mechanisms of disappearance; ameliorate effects of deleterious nonnative fishes.