6013

• UCREFRP Catalog Number: 6013
• Author: U.S. Fish and Wildlife Service, C. R. F. R. T.
• Title: Humpback Chup Recovery Plan.
• USFW Year: 1979.
• USFW - Doc Type: \
• Copyright Material: NO

istorical Distribution end Abundance
The humpback chub i• endemic to the Colorado River basin. It was
not reported before the 1940's because of its restrictiableoman ~adea ens
Consider
that were inaccessible to early researchers. before
alterations had occurred in the Colorado River aquatic c~isitsuggests
the 1940' a, especially in the lower basin (Miller 1961) . ~
the ossibility that populatioae of this species were lost due lleta(1955)
P
intervention before their existence was known. Yuinsx~arethe site of
reported on remains of this species from Indian back chubs existed
Hoover Dam. It is possible that a population of hump
erational in
in this area but were eliminated when Hoover Dam became op the were
the 1930'x. If population losses of this nature did occur, Y
probably restricted to the lower Colorado basin,as the upper basin,
Olsen's
including Grand Canyon, was little altered until the 1960'x.
(1976) record of "Gila ef. ~" from an Indian site in ~ stator G ver
basin must have been based on pharyngeal bones of Gila r
elm (see Minckley 1976).
Interest in Colorado River endemic fishes increased in the e9 lower
because of the rapid disappearance of these fishes in th
primarily
basin and the threat imposed by the Colorado River Storage Project dams
er basin. Until the 1950 s,the humpback chub was known only
in the upp ~
groin the Graced Canyon (Miller 1946). A number of surveys were made in the
rimarily p ost-impoundment
upper basin in the 1950's and 1960'x, p Cas on reservoir sites.
investigations of the Flaming Gorge and Glen ny
e rnambers in the upper Greece
Humpback chubs were found is relatively laY'g and in the Colorado
1960; Vanicek et al. 1970)
Rivet (Smith 1960; Bosley 1975•
olden and Stalnaker 1970,
River above and below~Glea Canyon Dam ~
Minckley 1973). Specimens were taken from Desolation Canyon of the middle
and the lower Yampa River
Green River in 1967 (Holden and Stalnaker 1970)
One individual was found in the
in 1969 (Holden and Stalnaker 1975).
Sdhite•River of Utah and another in the Colorado River near tiCnst tsh in
The most recent popuia
the 1950's(Sigler and Miller 1963). near the
discovered was in the Colorado River at Black Rocks (Colorado),
Utah-Colorado border (Johnson 197b; Kidd 1977)•
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