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The plankton net sampled a very small proportion of the water flowing <br />into Lake Powell and therefore was relatively ineffective at collecting eggs <br />and larvae in light of the size of the spawning population. The capture of <br />spent adults and four eggs indicated that spawning occurred above Gypsum <br />Canyon during 1980. The extent and success of spawning is unknown. <br />Information from 177 stomach samples agreed with reports from other <br />workers that striped bass in spawning condition generally do not feed during <br />their movements upriver (Raney 1952; Trent and Hassler 1966). Threadfin <br />shad was the most common item in stomachs of captured bass. <br />Interpretation of data on stomach contents of gillnetted striped bass <br />must consider possible regurgitation of food when netted and the rapid <br />digestion rate of this species (Merriman 1941; Raney 1952). Regurgitation <br />of food by gillnetted fish is a common phenomenon and results in lower <br />estimates of the percentage of fish feeding. The components of the diet <br />are not affected by regurgitation, only the percentage of stomachs containing <br />food. In our study, the similarity of the percentage of stomachs containing <br />food (32%) and intestinal tracts containing food (37%) suggested that regurgi- <br />tation was not a problem because regurgitation does not evacuate the intestine. <br />Rapid digestion rate can alter composition of stomach contents by digestion <br />of soft-bodied organisms first, but was also not considered a problem because <br />most of the food items were fish which should dissolve at a somewhat similar <br />rate. <br />Food habits of bass after entering the river above Lake Powell are <br />unknown. It is unlikely that threadfin shad provide a food source upriver <br />from the lake inasmuch as no shad have been captured above the reservoir <br />(Dr. R. Valdez, U.S.F.W.S. personal communication, 1980). Degree of bass <br />feeding after spawning was not determined because sampling was terminated <br />before many spent fish were captured.