Disclaimer:

The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: Apache Trout

Synonyms and Other Names: Behnke (1992) treated the Apache Trout as a subspecies (Oncorhynchus gilae apache), Arizona trout, yellow belly (Behnke 2002)

Taxonomy: available through www.itis.gov

Identification: Apache Trout have a short, stocky body that is moderately compressed and a yellowish golden coloration with dark olive on the head and dorsal (back) (Behnke 2002; Minckley and Marsh 2009). The dorsal, pelvic, and anal fins have white tips, along with a yellow, orange, or watery orange cut-throat mark (Minckley and Marsh 2009). Parr marks along the side are absent or reduced in all life stages (Behnke 2002). Apache trout are similar in coloration to the Gila trout (Oncorhynchus gilae), however, the yellowish coloration is restricted to the ventral region of the Apache trout (Behnke 2002). Additionally, the Apache Trout have larger and fewer spots compared to the Gila Trout. Pure strain Apache Trout have black pigment spots in front of and just behind the pupil, like a mask, but this trait is absent from many hatchery-raised fishes (Behnke 2002). In comparison to other western trout, the Apache trout has a larger dorsal fin.

Size: Length range of 13-23 cm and weight range of 28-170 g; maximum weight in lakes 230 g (Behnke 2002)

Native Range: Apache Trout historically occupied streams and rivers in the upper White, Black, and Little Colorado River drainages in the White Mountains of east-central Arizona (Arizona Game and Fish Department 2009).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: Apache Trout's native habitat are small cool water (< 25º C) creeks that are relatively unstable and occur, at the lowest, from 1,800 to 2,100 meters in elevation (Rinne and Minckley 1985, Behnke 2002, Arizona Game and Fish Department 2009). These creeks usually occur in mixed conifer and ponderosa pine forest (Arizona Game and Fish Department 2009). Lake populations have been stocked because there are no natural lakes occurring in the native range of the species (Behnke 2002). This species typically lives four years, but the maximum known is six years. Their diet consists of aquatic and terrestrial invertebrates (Behnke 2002). Adults are typically small in size because of their diet and habitat limitations.

Apache Trout require clean coarse gravel substrates for spawning and prefer cover in the form of woody debris, pools, coarse substrate such as gravel, cobble, and boulders, undercut stream-banks or overhanging vegetation at stream edges (Arizona Game and Fish Department 2009). Spawning occurs in the spring (May) when water temperatures are rising and snow runoff into streams is lower. Temperature seems to be the critical factor to the initiation of spawning. Females lay between 70 -300 eggs based on body size (Behnke 2002).

Widely stocked non-native trout species have impacted the Apache Trout. Brown Trout (Salmo trutta) and Brook Trout (Salvelinus fontinalis) devour eggs, fingerling, and parr and out-compete Apache Trout for food and space. Rainbow Trout (Oncorhynchus mykiss) and Cutthroat Trout (Oncorhynchus clarkii) will also predate on Apache Trout and hybridize with them (Arizona Game and Fish Department 2009; Minckley and Marsh 2009).

Means of Introduction: Stocked outside the native range for conservation efforts (Minckley and Marsh 2009).

Status: The Apache Trout Recovery Plan (2009) indicated that 27 pure (non-hybridized) Apache Trout populations exist within their historical range in Gila, Apache, and Greenlee counties of Arizona, on lands of the Fort Apache Indian Reservation and Apache-Sitgreaves National Forest.

Two streams outside of historical range have pure replicate populations, North Canyon Creek (Ord Creek stock) and Grant Creek (Pinaleño Mountains) stocked in the late 1960s (Arizona Game and Fish Department 2009).

Lakes and streams outside the native waters are maintained by stocking (Behnke 2002).

Impact of Introduction: As of yet, this species has not been adequately studied or evaluated to determine what ecological consequences, if any, have resulted from its introduction into the U.S. or elsewhere. To better understand and adequately assess the possible types and magnitude of any suspected ecological and economic impacts would most likely require further field and laboratory research, along with a review of any possible new literature on the subject.

Remarks: Designated as Arizona’s State Fish.

References: (click for full references)

Arizona Game and Fish Department, U.S. Fish and Wildlife Service, U.S. Forest Service, Trout Unlimited, White Mountain Apache Tribe, San Carlos Apache Tribe, National Fish and Wildlife Foundation. 2009. Apache trout recovery plan. Western Native Trout Status Report.

Behnke, R.J. 1992. Native trout of western North America. American Fisheries Society Monograph 6. American Fisheries Society, Bethesda, MD.

Behnke, R.J. 2002. Trout and Salmon of North America. The Free Press, NY.

Minckley, W.L., and P.C. Marsh. 2009. Inland fishes of the greater Southwest: chronicle of a vanishing biota. University of Arizona Press, Tucson, AZ.

Rinne, J.N., and Minckley, W.L. 1985. Patterns of variation and distribution in apache trout (Salmo apache) relative to co-occurrence with introduced salmonids. Copeia 1985(2):285-292.

Other Resources:
Western Native Trout Initiative- Apache Trout

Author: Daniel, W.M.

Peer Review Date: 8/15/2019

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.