7229

• UCREFRP Catalog Number: 7229
• Author: Kaeding, L. R. and M. A. Zimmerman
• Title: Life History and Ecology of the Humpback Chub in the Little Colorado and Colorado Rivers of the Grand Canyon
• USFW Year: 1983
• USFW - Doc Type: Transactions of the American Fisheries Society
• Copyright Material: YES

590
KAEDING AND ZIMMERMAN
Daylight
1.5 --LC 2
LC 3
......... LC 4
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Ct C7 C3 C4 C5 C6 C7
Confluence
Colorado River
FtcoRE 10.-Mean catch rates for humpb¢ck chubs col-
lected by trammel net fished overnight an the Colorado
River and its confluence with the Little Colorado River,
1980-1981. Numbers designate multiple observations.
shaped wounds on both sides of the body with
various degrees of healing and infection. This
observation suggests that channel catfish might
be an important predator on humpback chubs
in the Little Colorado. Humpback chubs and
channel catfish were sometimes observed in
shaded areas during daylight, particularly those
areas under overhanging rock ledges where
considerable opportunity for predation might
exist.
Meristic Variation
None of the juvenile or adult humpback chubs
handled in the field, or brought back to the
laboratory for taxonomic analyses (Glenn Clem-
mer, National Fish and Wildlife Laboratory,
USFWS, Fort Collins, Colorado, personal com-
munication)5 differed from published descrip-
tions of Gila cypha from the Grand Canyon area
(Suttkus and Glemmer 1977}. Eight combina-
tions of dorsal/anal fin-rap counts were found;
the 9/10 combination characteristic of hump-
back chubs was most common (Table 5). How-
1980 1981
FIGURE 9.-Mean catch rates for humpback chubs collected
by trammel net during three diet periods from reaches
LC 2, 3, and 4, Little Colorado River, 1980-1981.
Inflection points indicate collection date.
ever, parr-wtse chI-square analyses demonstrat-
ed that combination frequencies from LC 4 and
the confluence (C 4) differed significantly (P <
s All specimens have been deposited at the National
Fish and Wildlife Laboratory (see footnote 4).