7017

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

- the Green River system and in Debeque, Ruby and Westwater
canyons on the Colorado. Based on measurements taken from a
- large sample of mature live chubs from the Ruby Canyon area,
=i descriminate analysis was performed on fishes a priorily
classified as cypha, robusta, or unclassified (no suspected
elegans are mentioned) with high agreement between field and
mathematical classifications but with several specimens
being reclassified. The majority of specimens were
classifiable to cypha or robusta. Depth of nuchal hump was
the most useful discriminator. No identity (hybrid or
otherwise) of unclassified intermediates is speculated.
1985. Bestgen, K.R. Distribution, biology, and status of the
roundtail chub, Gila robusta, in the Gila River, New Mexico.
M.S. Thesis, Col. St. U., Ft. Collins. 104 p.
Concluded that upper Gila River system populations in New
Mexico all corresponded to G. robusta with the possible
exception of Turkey Creek which tended toward G. intermedia.
1985. Bookstein, F.L., B. Chernoff, R.L. Elder, J.H. Humphries
et al. Morphometrics in evolutionary biology. Acad. Nat.
Sci. Phila. Spec. Pub. 15. 277 p.
A morphometrics text which incorporates as examples of
principal components analysis the application of the
procedure to samples of Gila spp. from the Colorado River in
an attempt to detect intermediacy due to hybridization
versus that due to immaturity. Claims to have developed a
model for hybrid recognition based on partitioning of size
variation versus shape and postulating that hybridization
results in "unique variance". One analysis performed on
material for which localities are not given indicated a high
percentage of hybrids to be present.
1985. Hamman, R.L. Induced spawning of hatchery-reared
bonytail. Prog. Fish-Cult. 47:239-241.
Discusses techniques for culturing bonytail chubs but, of
taxonomic concern, documents the source of parental stocks
which may, along with offspring, conceivably enter into
taxonomic studies.
1985b. Valdez, R.A. Status of the distribution and taxonomy of
Gila cypha in the upper Colorado River. Proc. Desert Fish.
Coun. 12 (1980):53-60.
Somewhat dated at the time of publication (5 years after
presentation), this work reiterates problems of chub
identification in canyon areas of the upper Colorado but
problems had not yet been incurred to the degree related in
17