7155

• UCREFRP Catalog Number: 7155
• Author: Holden, P. B., W. White and G. Somerville
• Title: Threatened Fishes of Utah
• USFW Year: 1974
• USFW - Doc Type: 51, Part 2
• Copyright Material: YES

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47

lTfAH ACADEMY PROCEEDINGS, VOL. 51, PART 2,1974

3. Factors Influencing Decline. Reported important factors influencing
the decline of separate species or species inhabiting similar environ-
ments will be presented.
4. Recent Studies. Current or recently completed research will be noted.
5. Recommendations. General recommendations for chapter support of
paths of future research will be made. It is understood that the life
histories of many rare fishes have not been elucidated to any great
extent. We generally recommend, however, that support for rare fishes
be used for population status research first and for life history studies
secondarily.

CuMJuoat Trout

It must be emphasized that population trends are paramount in
separating cutthroat subspecies; thus individual specimens may not be dis-
tinguishable. Identification of possible "pure" populations is defmitely
difficult for persons unfamiliar with cutthroat subspecies. Dr. Robert
Behnke, Colorado State University, is available for classification of
cutthroat populations and currently is the. authority for identification of
specimens.

Salmo clarki pleuriticus-ColoradoCutthroat Trout

Status: Endangered subspecies
Description: There are virtually no published descriptions of the Colorado
cutthroat trout. Behnke (1973) gives the following characters: "Spots,
large and pronounced, concentrated mainly posteriorly; scales in lateral
series (counted two rows above lateI3lline) 175-200+; scales above lateral
line 38-48; vertebrae 61-63; pyloric caeca, mean values typically 3040;
gillrakers, 18-22; basibranchial teeth present, typically 1-15. Coloration
may be gaudy, particularly on males irt breeding season, red-crimson and
orange and yellow colors emphasized. In some specimens, whole ventral
region may be crimson."
Documentation: Original range of tile Colorado cutthroat trout was the
upper Colorado River basin of Wyoming, Colorado, Utah, and New
Mexico. In Utah the Uinta Mountains and plateaus draining into the Green
River as far south as the Dirty Devil River contained this subspecies
(Behnke, 1973). Presently in Utah it is known only in the Little West Fork
of the Blacks Fork River, Summit County. It is also found in three
Wyoming and three Colorado streams. aU small headwaters.

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