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

2. General Description - Body streamlined, skull concave on top.
Nape abruptly elevates to a prominent hump that may project
forward slightly over the head in adults. Caudal peduncle
thin, somewhat pencil-like but not greatly elongated. Scales
embedded or lacking (especially in hump). Fins large and
falcate. Body deep, making it appear the head is too small
for the body. Mouth inferior, overhung by snout. Color
dark above, light below. Paired fins often dusky, with
some yellow pigment near bases. Maximum size around 20
inches and two pounds.
3. Present Distribution and Status (Fig. VI) - Recent collec-
tions have been made from the mainstream Colorado River in
the Grand Canyon and below Lake Powell (Arizona), the Green
River at its confluence with the White and Yampa rivers and
the lower Yampa River (Holden & Stalnaker, 1975). Reduced
reproductive success and declining populations seem to typify
all of these sites except the Grand Canyon. DOW personnel
took 32 specimens out of the Colorado River above and below
Grand Junction, Colorado, on August 10, 1974. At present
this is the largest known concentration of both young and
adult humpback chubs.
4. Existing Management Plans - Because of the relatively harsh
environment of this species, not enough of its ecological
requirements are known to begin extensive management plans.
In their Endangered Animals Cooperative Agreement Applica-
tion (1974), the State of Colorado has indicated further
distributional and ecological data is needed. The State has
also prohibited capture of humpback chubs in 1975.
5. BLM Interest - At present the only known breeding population
of humpback chubs is in the Colorado River around Grand
Junction. National Resource Lands abut much of this area
and should be thoroughly inventoried as quickly as possible
to determine if G. cypha is still present. Humpback chub
populations are also likely to be found on NRL abutting the
lower Yampa, White, Gunnison, and Dolores rivers. These
areas should also be inventoried for existing population and
potential reintroduction sates. The State has become aware
of BLM's interest in this and other endangered fishes, so
efforts should be made to continue and enlarge this contact
through Recovery Teams and field inventory assistance.

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