Gila trout

What it is

The Gila trout is a member of the salmon family, closely related to rainbow and Apache trout. It displays a yellow body covered in numerous small dark spots on its upper half. Unlike its Apache cousin, it lacks large spots or markings near the eye. Adults typically reach 30 centimetres in length, though some grow up to 55 centimetres. This copper-hued fish inhabits high-altitude waters in the southwestern United States.

Where it lives

Historically, this species occupied the Verde and Agua Fria drainages in Arizona, with anecdotal records from Tonto Creek. Today, wild populations persist in five specific streams within the Gila and Aldo Leopold Wilderness Areas of New Mexico. These include Iron, McKenna, and Spruce creeks, as well as Main and South Diamond creeks. The fish is native to tributaries of the Gila River across Arizona and New Mexico.

How it lives

These trout dwell in small mountain streams and isolated pools. They are opportunistic feeders, consuming aquatic insects such as caddisflies, mayflies, midges, and beetles. Small fishes also form part of their diet. Their survival depends on cool water temperatures maintained by shade-giving trees and healthy riparian vegetation.

Breeding and life cycle

Spawning takes place in late spring or summer, depending on water temperature. Females held in hatcheries produce an average of 150 eggs, with a maximum observed count of 686. Restocking programmes use young fish bred from brood stocks kept at the Mora National Fish Hatchery in northern New Mexico.

Fish and people

Fishing for this trout was banned in the 1950s due to severe population declines. In July 2006, federal agencies down-listed the species from endangered to threatened. A special rule now permits limited sport fishing in both Arizona and New Mexico. Conservationists aim to delist the species entirely by building alliances with anglers to support preservation efforts.

Status and threats

Habitat loss remains the primary threat, driven by water diversion, irrigation, livestock grazing, and fire. Competition and hybridization with introduced rainbow trout also pose risks. By 1967, the range had shrunk to just 20 miles of stream. Restoration work has since expanded populations to ten new streams, improving security compared to the 1970s, though levels remain below historical norms.

Relatives and look-alikes

The Gila trout is closely related to the Apache trout. The two can be distinguished by spot patterns: Apache trout often have large spots and markings near the pupil, while Gila trout feature many small dark spots on the upper body.

Questions people ask about Gila trout

Good reading and sources

• Gila trout on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data