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Abundance, Growth, and Diet of Channel Catfish, Ictalurus punctatus, in the Green and Yampa Rivers, Colorado and Utah
Harold M. Tyus and Neil J. Nikirk
The Southwestern Naturalist
Vol. 35, No. 2 (Jun., 1990), pp. 188-198
Published by: Southwestern Association of Naturalists
Stable URL: http://www.jstor.org/stable/3671541
Page Count: 11
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Channel catfish were widely distributed in 517 km of the mainstream Green and 74 km of the lower Yampa rivers in 1987 and 1988. The fish was most abundant in rocky canyon habitats (average stream gradient >2 m/km), where adult fish comprised 14% of electrofishing and 70% of angling catch. Pectoral spine sections of 364 channel catfish of 27 to 756 mm total length ranged in age from 0 to 22 years respectively, with an average annual growth range of 17 to 53 mm. No difference in growth or condition factor was detected among catfish collected in eight river reaches. Growth of channel catfish in the Green River basin was judged slow in comparison to other areas of the United States and was attributed, in part, to cold water temperatures, short growing seasons, and elevated summer flow conditions. Channel catfish consumed a variety of food items, but piscivory was limited to larger fish (average length 420 mm). Of 575 stomachs with food (76.2%), 31% contained aquatic invertebrates, 28% contained vascular plant material, 22% contained terrestrial insects, 10% contained algae and detritus, and 8.5% contained fish and mice. The abundance, widespread distribution, and omnivorous feeding behavior of this introduced fish may affect populations of rare and endangered fishes in the Green River basin.
The Southwestern Naturalist © 1990 Southwestern Association of Naturalists