ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Leuciscidae Leuciscidae is a family of freshwater ray-finned fishes, formerly classified as a subfamily of the Cyprinidae, which contains the true minnows. Members of the Old World (OW) clade of minnows within this subfamily are known as European minnow ...

dace A dace is a small fish that can be one of many different species. The unmodified name is usually a reference to the common dace (''Leuciscus leuciscus''). This, like most fish called "daces", belongs to the family Leuciscidae, mostly in subfami ...

chub Chub is a common fish name. It pertains to any one of a number of ray-finned fish in several families and general. In the UK, the term ''chub'' usually refers to the species '' Squalius cephalus''. In addition, see sea chub. In family Cyprinid ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Colorado River The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United St ...

drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

Gila River The Gila River (; O'odham ima Keli Akimel or simply Akimel, Quechan: Haa Siʼil, Maricopa language: Xiil) is a tributary of the Colorado River flowing through New Mexico and Arizona in the United States. The river drains an arid watershed of ...

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Bidahochi Formation of Arizona. This suggests that the Colorado River had already developed its iconic swift-river habitat by this point in time.

Description

The body of the roundtail chub is significantly larger forward of the

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

, and posteriorly it is tapered towards the tail. The forehead area is concave. The mouth is largish, but does not reach as far as the pupil of the eye, and is overhung by the snout. The tail is deeply forked. Color is a grayish brown above, and a lighter shade below. Mature males sometimes acquire red-orange lower cheeks and paired fins during breeding season. Roundtail chub can reach almost , but usually only grow to about . Recently, it has been recorded at up to in length.
Roundtail chub are also described to be "trout-like" because they possess a large mouth with the lower lip outlined in black. However, they lack the adipose fins found on trout species.

Range

Its range of is within the Colorado River drainage basin, found from the headwaters down to the mouth, in Utah, Colorado, Arizona, Nevada, and California, and northwest Mexico; as well as in other rivers of northwestern Mexico. This species is rather variable, and formerly accounted as several species, until intermediate forms were discovered. Recognized subspecies include: * ''Gila robusta grahami'' * ''Gila robusta jordani'' - small streams along the

White River (Nevada) The White River is a small and discontinuous river located in southeastern Nevada notable for several endemic species of fish. The river was named for F. A. White, a 19th-century explorer. Course The White River begins at the Great Basin Divid ...

* ''Gila robusta robusta'' - small rivers * ''Gila robusta seminuda'' The roundtail chub has been extirpated from the Zuni and San Francisco Rivers of New Mexico. In Arizona, specifically in Gila, Mohave, and Yavapai Counties, the roundtail chub occupies several tributaries:

Fossil Creek Fossil Creek ( or ) is a perennial stream accessed by forest roads near the community of Camp Verde, Arizona, Camp Verde in the U.S. state of Arizona. Primary access is from Forest Road 708 off Arizona State Route 260 east of Camp Verde. A tri ...

, Oak Creek, Burro Creek, Francis Creek, Big Sandy River, Santa Maria River, Boulder Creek, Trout Creek, Sycamore Creek, Beaverhead Springs, and throughout the

Verde River The Verde River ( Yavapai: Haka'he:la) is a major tributary of the Salt River in the U.S. state of Arizona. It is about long and carries a mean flow of at its mouth. It is one of the largest perennial streams in Arizona. Description The ri ...

. It is also found in the

Gila River The Gila River (; O'odham ima Keli Akimel or simply Akimel, Quechan: Haa Siʼil, Maricopa language: Xiil) is a tributary of the Colorado River flowing through New Mexico and Arizona in the United States. The river drains an arid watershed of ...

and the

Rio Yaqui The Yaqui River (Río Yaqui in Spanish) (Hiak Vatwe in the Yaqui or Yoreme language) is a river in the state of Sonora in northwestern Mexico. It was formerly known as the Rio del Norte. Being the largest river system in the state of Sonora, ...

.

Biology

Roundtail chub is very prolific in nature.

Diet

Roundtail chub is a voracious predator, consuming large amounts of fish,

crayfish Crayfish are freshwater crustaceans belonging to the infraorder Astacidea, which also contains lobsters. Taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some spe ...

, frogs, and insects. Roundtail chub adults primarily consume aquatic and terrestrial insects, other fishes, and sometimes algae. Roundtail chub juveniles eat smaller insects, crustaceans, and algae.

Conservation

The decreasing population of the roundtail chub is primarily the result of habitat loss as well as predation and competition by non-native fish. Although the populations in the

Salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

and

Verde River The Verde River ( Yavapai: Haka'he:la) is a major tributary of the Salt River in the U.S. state of Arizona. It is about long and carries a mean flow of at its mouth. It is one of the largest perennial streams in Arizona. Description The ri ...

s were stable ten years ago, they have been exponentially decreasing. Recent conservation efforts include more research to determine the mechanisms of their sudden disappearance, and population surveys conducted by the Arizona Game and Fish and US Forest Service (in progress). Arizona Game and Fish Department considers roundtail chub a sport fish. They put up a strong fight for anglers, and the meat is described as "firm, white and very mild tasting." Intermuscular bones or floating bones are present, which can be cut out prior to cooking. It is a candidate

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

of the

United States Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is a List of federal agencies in the United States, U.S. federal government agency within the United States Department of the Interior which oversees the management of fish, wildlife, ...

, under the

Endangered Species Act The Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting and conserving imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of e ...

criteria.USFWS —Species Profile for Roundtail chub (Gila robusta)
. accessed 6.16.2013

References

* Ira La Rivers, ''Fishes and Fisheries of Nevada'' (University of Nevada Press, 1994), pp. 388–390 * {{Authority control Chubs (fish) Gila (fish)

Chub Chub is a common fish name. It pertains to any one of a number of ray-finned fish in several families and general. In the UK, the term ''chub'' usually refers to the species '' Squalius cephalus''. In addition, see sea chub. In family Cyprinid ...