It has been shown in other studies that insects are significant in the 

 catfish diet. Stomachs of channel catfish from the Mississippi River in 

 Iowa contained a dominance of insects, of which 68.0 percent were Hexagenia 

 nymphs, a still -water bottom burrower, and imagoes of the same species 

 (Hoopes 1960). Hoopes collected catfish from April to October, during the 

 peak of insect emergences. In another study, also conducted from April 

 through October, Bailey and Harrison (1948) found that insects were an 

 important part of the diet of the southern channel catfish (latalurus 

 laaustris punatatua); 98 percent of the stomach volume of catfish up to 

 100 nm (3.94 in) consisted of insects. For fish exceeding 300 ran (11.81 in), 

 the insect volume was 28.0 percent, and the fish volume was 35.0 percent. 



GOLDEYE 



Goldeye fed almost exclusively on insects (table 46). Traverella 

 albertana, the dominant aquatic species, accounted for 70.5 percent of the 

 volume of identified insects. This was similar to Hoopes' (1960) results 

 in which 56.0 percent of the goldeye diet consisted of Hexagenia nymphs, 

 another Ephemeroptera genus. Grasshoppers were also present in many goldeye 

 stomachs from the Yellowstone River. More than 52.0 percent of the total 

 volume consisted of unidentified insect parts, which implies that digestion 

 occurs rapidly in the goldeye. 



SHOVELNOSE STURGEON 



As with the goldeye, insects comprised more than 95.0 percent of the 

 stomach contents of shovelnose sturgeon. Sturgeon collected in May and June 

 had fed heavily on hydropsychid caddisflies (table 47). In most stomachs, 

 the heads of caddis larvae were separated from the bodies, and generic 

 identification was not possible. The larval bodies were complete in two 

 stomachs which contained a total of 491 Hydropsyche, 7 Cheumatopsyche, 

 and 53 damaged caddis larvae. 



Hydropsychid caddisflies were present in 90.5 percent of the stomachs 

 of sturgeon captured from July through September (table 48), but amounted to 

 only 1.9 percent of the volume. During this period, Traverella, the primary 

 food organisms, comprised 46.2 percent of the diet. 



Fine gravel particles were present in several sturgeon stomachs. Most of 

 this material was from the pupal cases of Trichoptera. 



In a one-year study of food habits of the shovelnose sturgeon in the 

 lower Missouri River, Moode (1973) found that chironomid larvae formed the 

 bulk of the sturgeon diet from April through September. During the remainder 

 of the year, Hydropsyahe was the dominant food organism. Sturgeon stomachs 

 collected by Held (1966) in June contained a chironomid volume of almost 

 54.0 percent. Hydropsychid larvae accounted for 75.0 percent of the sturgeon 

 diet in the Mississippi River (Hoopes 1960). 



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