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6 <br />Channel catfish were sorted into eight groups based on the reach in which <br />they were collected. Analysis-of-variance (ANOVA) was used for comparing back- <br />calculated lengths at age 1, 3, 5, 7, and 9, for evaluating condition factor <br />(K) between reaches, and for evaluating differences in mean lengths of fishes <br />consuming different foods. <br />Stomachs were removed from channel catfish collected in the Green and <br />Yampa rivers from May to July 1987 and 1988. Consumed foods were recorded for <br />each stomach based on the following major food categories: aquatic <br />invertebrates, terrestrial insects, fish, mice, vascular plants, algae and <br />detritus. The number of stomachs containing a food category and a resultant <br />frequency of occurrence (%) were reported. No effort was made to determine <br />food volume. Stomachs with no food were reported as empty. <br />River discharge, water temperatures, and sediment concentrations of the <br />Green River were obtained from U.S. Geological stream gauging stations at <br />Green River and Jensen, Utah (ReMilliard et al., 1988). The effects of river <br />discharge and water temperatures on growth of age 0 channel catfish were <br />evaluated using simple linear regressions. <br />RESULTS AND DISCUSSION--Abundance--Adult channel catfish comprised 8.3% <br />of the total catch of fishes (n = 6097, Table 1). Five species amounted to <br />91.3% of the catch as follows: flannelmouth sucker, Catostomus latiainnis, <br />(31.8%); carp, Cyprinus car io, (29.6%); bluehead sucker, Catostomus <br />discobolus, (16.2%); channel catfish (8.3%), and roundtail chub, Gila <br />robusta, (5.5%). Highest catches of 19.6 and 11 channel catfish/h were taken <br />in the Yampa and upper Green rivers (stratum G), the most rocky and turbulent <br />