7719

• UCREFRP Catalog Number: 7719
• Author: Seethaler, K. H.
• Title: Resume of Current Knowledge on Colorado Squawfish.
• USFW Year: 1976.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

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{~1b Resume of Current Knowledge on Colorado Squawfish
Karl Seethaler

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Utah Cooperative Fishery Research Unit
Utah State University UMC 52
Logan, Utah 84322

To my knowledge, my study of the Colorado squawfish (P,Ytchocheilus
lucius) is the first on a graduate research level devoted specifically
to that species. At Utah State University there have been two

previous studies, both Ph.D. dissertations, which have incorporated

the status and life history of the Colorado squawfish. The first was
that of Charles Vanicek completed in 1967: Ecological Studies of
Native Greenriver Fishes Below Flaming Gorge Dam, 1964-1966. The
second was completed in 1973 by Paul Holden on field work done in
the years 1968-1971: Distribution, Abundance and Life History of

the Fishes of the Upper Colorado River Basin.
Following the closure of Flaming Gorge Sam and the rotenone
operation of September 4-7, 1962, there continued a debate over the

downstream effect or the~e operations upon the river fauna. The

Utah Cooperative Fishery Research Unit was assigned by the Bureau of
Sport Fisheries and Wildlife to investigate this aspect. Vanicek's

study was a part of the overall program. His study area extended from

Falming Gorge Dam to the mouth of the White River. He compiled useful
data or. life history, habitat, distribution, food habits, age and growth,

reproduction, parasites and water chemistry.

Holden's survey was less intensive, but more extensive. He

sampled sites throughout the Upper Colorado Basin. He has contributed

data on distribution and abundance from parts of the Yampa, Green,

Colorado, Dulur~s ~nd Gunnison rivers. He has documented the continued

decline in spawning success since the time of Vanicek's study when

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