The Tui chub, Gila bicolor, is a cyprinid

Cyprinid

The family Cyprinidae, from the Ancient Greek kyprînos , consists of the carps, the true minnows, and their relatives . Commonly called the carp family or the minnow family, its members are also known as cyprinids...

 fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

 native to western North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. Widespread in many areas, it is an important food source for other fish, including the cutthroat trout

Cutthroat trout

The cutthroat trout is a species of freshwater fish in the salmon family of order Salmoniformes. It is one of the many fish species colloquially known as trout...

.

Range

The Tui chub's range includes the Lahontan

Lake Lahontan (reservoir)

Modern Lake Lahontan is a reservoir on the Carson River in northwest Nevada in the United States. It is formed by the Lahontan Dam and is located between Fallon, Nevada and Carson City, Nevada. The flows from the Carson River is augmented by diversions from the Truckee River...

 and Central system of the Great Basin

Great Basin

The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...

, as well as the Owens

Owens River

The Owens River is a river in southeastern California in the United States, approximately long. It drains into and through the Owens Valley, an arid basin between the eastern slope of the Sierra Nevada and the western faces of the Inyo and White Mountains. The river terminates at Owens Lake, but...

 and Mojave River

Mojave River

The Mojave River is an intermittent river in the eastern San Bernardino Mountains and Mojave Desert in San Bernardino County, California. The river is notable as most of its flow is underground, while its surface channels remain dry most of the time, with the exception of the headwaters and several...

s. It is found in the Pit River

Pit River

The Pit River is a major river draining from northeastern California into the state's Central Valley. The Pit, the Klamath and the Columbia are the only three rivers in the U.S...

 and Goose Lake

Goose Lake (Oregon-California)

Goose Lake is a large alkaline glacial lake located in the Goose Lake Valley on the Oregon-California border. The north end of the lake is in Lake County, Oregon and the south end is in Modoc County, California. The mountains at the north end of the lake are part of the Fremont National Forest...

 of the upper Central Valley, in the Klamath River

Klamath River

The Klamath River is an American river that flows southwest through Oregon and northern California, cutting through the Cascade Range to empty into the Pacific Ocean. The river drains an extensive watershed of almost that stretches from the high desert country of the Great Basin to the temperate...

 system, and in the Columbia River

Columbia River

The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...

 drainage.

Description

The form and appearance of the Tui chub is variable; many were originally described as different species by J. O. Snyder, but have since been reduced to subspecies. In general, the color is deep olive above and white below, with a smooth variation in shading along the sides, and a brassy reflection. Fins are olive and sometimes tinted with red. The pectoral fins are far forward and low on the body. Length has been recorded at up to 45 centimetres (18 in), but 25 centimetres (10 in) is more typical.

Habitat and behavior

Tui chubs are found in a variety of habitats, including anything from small streams to large lakes and reservoirs, and both high cold lakes, such as Lake Tahoe

Lake Tahoe

Lake Tahoe is a large freshwater lake in the Sierra Nevada of the United States. At a surface elevation of , it is located along the border between California and Nevada, west of Carson City. Lake Tahoe is the largest alpine lake in North America. Its depth is , making it the USA's second-deepest...

, and warmer desert streams.

They spawn between late April and early August, depending on temperatures. In Pyramid Lake the peak season is June; males move inshore first, then congregate around arriving females in shallow water, preferring areas of heavy vegetation. The female scatters her eggs randomly over a wide area, where they are then fertilized by several males. The hatchling

Hatchling

In oviparous biology, a hatchling is the newborn of animals that develop and emerge from within hard-shell eggs. The offspring of birds are often hatched naked and with their eyes closed. The hatchling relies totally on its parents for feeding and warmth. Hatchlings precede nestlings in the chick's...

s remain in the heavy vegetation for the remainder of the summer. In Lake Tahoe some chubs spawn around stream mouths in July.

Tui chub diet is varied; young fish eat mostly invertebrate

Invertebrate

An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

s, adding plant material and especially algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 as they mature. Habits also vary by location and the fineness of the gill raker

Gill raker

Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch and are involved with filter feeding tiny prey. They are not to be confused with the gill filaments that compose the bony part of the gill. Rakers are usually present in two rows, projecting from both the...

s, so for instance fine-rakered forms in Pyramid Lake feed more on plankton

Plankton

Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...

 in open water than the coarse-rakered forms, who live near the botton and eats more plants and algae. The largest individuals will eat other fish also. In Pyramid Lake the endangered Lahontan cutthroat trout

Lahontan cutthroat trout

Lahontan cutthroat trout is the largest subspecies of cutthroat trout, and the state fish of Nevada.-Natural history:...

 feeds on the Tui chub; the Lahontan cutthroat trout has been studied extensively due to water management decisions affected the water quality of the Truckee River

Truckee River

The Truckee River is a stream in the U.S. states of California and Nevada. The river is about long. Its endorheic drainage basin is about , of which about are in Nevada. The Truckee is the sole outlet of Lake Tahoe and drains part of the high Sierra Nevada, emptying into Pyramid Lake in the Great...

 and Pyramid Lake.

Subspecies

The exact number of subspecies is not known; Sigler & Sigler estimate as high as 16. Agreed subspecies include:

• Gila bicolor bicolor
• Gila bicolor isolata (extinct
  Extinction
  In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
  
  )
• Gila bicolor mohavensis
• Gila bicolor obesa
• Gila bicolor pectinifer
• Gila bicolor snyderi