7017

• UCREFRP Catalog Number: 7017
• Author: Starnes, W. C.
• Title: Colorado River Basin
• USFW Year: 1989.
• Copyright Material: NO

Contains a brief description and summary of taxonomic
studies of the humpback chub. Offers a thorough discussion
of the difficulties encountered in positive identification of
humpback-like chub specimens and a summary of previous
studies attempting to clarify these problems.
1989. Douglas, M.E., W.L. Minckley, and H.M. Tyus. Qualitative
characters, identification of Colorado River chubs
(Cyprinidae: genus Gila) and the "art of seeing well".
Copeia 1989:653-662.
Presents a new approach to analyzing morphology in Colorado
Gila spp. utilizing a multivariate analysis of qualitative
(versus quantitative) characters. The study focused on the
lower Yampa River chub population which has not yielded
problematic intermediate specimens (e.g., see Tyus and Karp,
1989, below) common in samples from other canyon areas of
the upper Colorado River basin. The analysis, performed on
live specimens, resulted in complete descrimination of
groups assignable to G. cvpha and G. robusta with no hybrids
indicated; these groups failed to emerge completely in
concurrent analysis of a small number of quantitative
attributes obtained from the same specimens. This degree of
separation had not been achieved in other studies utilizing
quantitative techniques (though these were performed on
other populations with obvious problematic specimens). A
lengthly discussion of the potential utility of such
qualitative assessment is presented along with philosophical
arguments. Perhaps of most interest to impending taxonomic
studies is the fact that specimens from this relatively
undisturbed habitat might serve as a basis for comparison in
analyzing phenotypic and genetic variability in downstream
populations which have yielded problematic intermediate
specimens.
1989. Minckley, W.L., D.G. Buth, and R.L. Mayden. Origin of
brood stock and allozyme variation in hatchery-reared
bonytail, and,endangered North American cyprinid fish.
Trans. Amer. Fish. Soc. 118:131-137.
A study designed to determine genetic variability in
hatchery-reared bonytails in a large part aimed at
determining their suitability for stocking in wild habitats.
Of taxonomic interest is the fact that genetic
heterozygosity was found to exist comparable to that found
in other western minnows eventhough the bonytail brood stock
was from a restricted area (Lake Mohave). Of interest to
future taxonomic studies, if material from upper basin areas
becomes available, interregional genetic studies may be more
meaningful if specimens from now restricted populations are
maintaining something approaching normal variation. A
foundation for future comparative allozyme studies of Gila
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