7361

• UCREFRP Catalog Number: 7361
• Author: Tyus, H. M. and N. J. Nikirk.
• Title: Abundance, Growth, and Diet of Channel Catfish,
• USFW Year: 1989.
• Copyright Material: NO

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noted that food conversion of channel catfish increased as the water
temperature was warmed 22 to 30°C. If warmer temperatures resulted in better
growth and larger size of channel catfish, their piscivory on native fishes
would presumably increase.
Channel catfish were abundant and widely distributed in the Green and
Yampa rivers, particularly in rocky canyon habitats. Growth of catfish was
slow in this area relative to that in other regions, but the sheer weight of
its numbers indicated that establishment of channel catfish in the Green River
basin is permanent. However, its preference by anglers is low relative to that
for trout, and its greatest abundance occurs in virtually inaccessible
canyons. Recovery of the endangered Colorado River fishes has not yet included
thorough investigations of potential interactions with channel catfish even
though they are sympatric in specific microhabitats. Habitat modifications
(e.g, flow regulation, thermal changes) that may favor growth and further
proliferation of channel catfish in the Green River basin must be carefully
evaluated with respect to potential adverse impacts on native fishes.
This work was funded by the U. S. Bureau of Reclamation and the U. S.
Fish and Wildlife Service. Many employees of the U. S. Fish and Wildlife
Service participated in data collection. C. A. Karp, L. A. Trinca and others
assisted in the identification of fish stomach contents. M. H. Hughes, D. A.
Adriansen, K. S. Devenport, and D. A. Strejc assisted in sectioning,
polishing, and reading spines. We thank R. A. Whaley for reading sample
catfish spines. C. A. Karp and G. B. Haines helped with statistical analyses.
C. A. Karp, W. G. Layher, and an anonymous reviewer improved an earlier
version of the manuscript.