FWS Focus

Overview

Characteristics
Overview

The Apache trout (Oncorhynchus apache, formerly Salmo apache) is the state fish of Arizona, and is one of two salmonid subspecies native to Arizona. The other is gila trout, Oncorhynchus gilae. The White Mountain Apache Tribe took the first critical steps to conserve and protect this species in 1955, by closing fishing in reservation waters that contained any remaining native Apache trout populations. They also worked to manage timber harvest and grazing, constructed non-native fish barriers and conducted suppression and eradication of invasive trout species. The Apache trout was originally listed as endangered under the Federal Endangered Species Preservation Act of 1966 and later became federally protected with passage of the Endangered Species Act in 1973. The Apache trout was downlisted to threatened in 1975. Sport fishing of Apache trout was permitted when the reclassification to threatened status become effective. Threats to the species include hybridization with introduced rainbow and cutthroat trout, predation, competition by introduced fishes, and habitat degradation.

Currently, Apache trout recovery partners are completing a species status assessment and cooperative management plan which will describe the current condition of the species, forecast the future condition for the species and relate a plan to achieve recovery. All this will provide for long-term management when the Apache trout is recovered and removed from the federal list of endangered and threatened wildlife.

Scientific Name

Oncorhynchus apache
Common Name
Apache trout
Arizona trout
FWS Category
Fishes
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

Apache trout are found in streams that flow through mixed conifer forests and mountain meadows at elevations above 5,905 to 6,900 feet in elevation (1,800 to 2,100 meters). They require cold and clean water, generally below 77°F and spawning habitat consists of gravels free of fine sediment.

Apache trout seek out rearing habitat along stream margins and other areas that contain velocity refuges, or slow moving water, pools, and cover elements, like undercut banks, boulders, that provide juveniles and adults places to seek refuge while they feed and grow. Adequate stream flow and shade are generally required to maintain pools that are frequently used by Apache trout during periods of drought and temperature extremes. Pure populations of Apache trout are typically above 6,900 feet in elevation (2,100 meters) and often above natural barriers like waterfalls, keeping non-native trout from invading into those habitats. This, along with closed access to fishing, have resulted in 17 relict populations of Apache trout that remain free of hybridization, with 30 total pure populations.

Lake
River or Stream

A natural body of running water.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

Apache Trout have a fusiform body, meaning that it is wide in the middle and tapering at both ends, and a large dorsal fin.

Measurements
Fry length: Less than 3.9 inches (100 millimeters)
Juvenile length: 3.9 to 5.1 inches (100 to 129 millimeters)
Adults length: Greater than or equal to 5.1 inches (130 millimeters)

Color & Pattern

Apache trout have spots on the body, that are pronounced and often uniformly spaced, above and below the lateral line. These trout are predominately a golden yellow or yellow-olive color with tints of purple and pink. Two black spots are located horizontally on either side of the pupil, creating the image of a black band through the eye. A red or pink lateral band is usually absent and parr marks or dark vertical marks, can be retained in adults. Dorsal, pelvic and anal fins have conspicuous cream or yellowish tips. A yellow cutthroat mark is usually present and basibranchial teeth, which are located on the base of the tongue, are occasionally present.

Weight

The maximum reported weight for an Apache trout is 5 pounds, 4 ounces.

Characteristic category

Life Cycle

Characteristics
Life Cycle

Apache trout are reproductively mature around 3 years old. The annual survival rate for Apache trout ranges from 48 to 70%.

Life Span

The life span of an Apache trout is typically five years, although a recent age and growth study suggests they can live 9 years or more.

Reproduction

Spawning occurs from March through mid-June and varies with stream elevation. Females excavate redds, or nests, in the gravel. After fertilization by male Apache trout, the eggs are covered with gravel. Incubation lasts about 30 days and young Apache trout emerge from their redds after about 60 days. Each female can lay 200 to 600 eggs.

Characteristic category

Similar Species

Characteristics
Similar Species

Other Oncorhynchus species are closely related to the Apache trout and have been shown to hybridize with them. Apache trout and Gila trout are believed to have derived from a common ancestor that gained access to the Gila River from the Gulf of Mexico.

Characteristic category

Food

Characteristics
Food

Apache trout are largely opportunistic and feed on a variety of aquatic and terrestrial organisms.

Characteristic category

Behavior

Characteristics
Behavior

Adult Apache trout and larger juveniles generally use pool and eddy habitats in deeper or higher velocity water. Fry and smaller juveniles are found in low velocity water that is generally shallower.

Geography

Characteristics
Range

Apache trout inhabit cold water streams in the White Mountains of Arizona. There are currently 30 genetically pure Apache trout populations in the Black, White, Little Colorado and Colorado basins. The only recovery stream outside of the White Mountains is North Canyon Creek on the Kaibab in Arizona. 

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