7327

• UCREFRP Catalog Number: 7327
• Author: Johnson, J. E.
• Title: Status of Endangered and Threatened Fish Species in Colorado.
• USFW Year: 1976.
• USFW - Doc Type: T/N 280,
• Copyright Material: NO

and belly whitened, especially anteriorly. Young with a
dark, wedge-shaped basicaudal spot, absent in adults
(Minckley, 1973). Squawfish once attained a weight of
nearly 100 pounds and lengths approaching 6 feet, the world's
largest minnow (Family Cyprinidae). Modern records indicate
smaller (younger) fish (up to 10 pounds and 3 feet) have
completely replaced the larger fish.
3. Present Distribution and Status (Fig IV) Probably totally
extirpated in the lower Colorado River and its tributaries.
Recent collections indicate declining populations in the
Colorado River between Lake Powell and Grand Junction, Colo-
rado; portions of the Green River below Ouray, Utah; and the
Yampa River below Craig, Colorado (McFarland, 1975). Collec-
tions indicate reduced spawning success in all areas. No
squawfish were found in 1970-1972 collections from the
Dolores River made by the Utah Cooperative Fishery Unit
(Holden & Stalnaker, 1973) and the Colorado DOW. Unverified
reports of squawfish being caught in the White River are
being investigated.
4. Existing Management Plans - Surprisingly little is known
of the environmental requirements of Colorado squawfish.
Several universities (Utah State, Colorado State, Arizona
State and perhaps others) are interested in life history
research, and F&WS, Forest Service and BLM are continuing
distribution and habitat studies. During spring, 1974,
adult fish in pre-spawning condition were captured in the
Yampa River, Colorado and transported to Willow Beach
Federal Fish Hatchery. After pituitary injections they.
spawned in hatchery ponds and their offspring are being
reared successfully. It is anticipated the young fish will
be stocked in one of the Arizona or Colorado tributaries
of the Colorado River, sometime in late 1975. Colorado
DOW has tentative plans to attempt artificial propagation
in the Bel Aire Hatchery in 1975 or 1976. A Colorado
squawfish recovery team has been formed by the U. S. Fish
and Wildlife Service and includes personnel from BLM,
F&WS, and Colorado, Utah, Arizona and California Fish and
Game departments.
5. BLM Interest - Some of the most promising habitat remaining
to Colorado squawfish abuts NRL in Colorado. These should
be thoroughly inventoried both for existing populations and
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