of food. No other insects were present in the 

 stomachs of walleyes from this area. 



Island Region (Area 2) 



Of the 562 walleyes collected from Area 2 

 (table 4) the late June sample of 176 individuals 

 (mean length 55 mm.) required special treatment. 

 All stomach contents of these small fish were 

 examined with a dissecting microscope. The 

 major food at this time was unidentifiable fish 

 fry (frequency of occurrence — 65.5 percent). 

 Many of the fry probaby were yellow perch but 

 positive identification was impossible, because of 

 their small size. Leptodora kindtii appeared in 

 16.5 percent of the stomachs. Consumption of 

 Diaptomus , Cyclops, and Daphnia was limited as 

 was also that of unidentifible midge larvae and 

 pupae. Ewers (1933) found Leptodora the most 

 common of the Entomostraca in the diet of young 

 walleyes and blue pike in western Lake Erie. 

 The stomachs of 23 walleyes caught in the latter 

 part of July 1929, and examined by Boesel ' 



1 Boesel, M. W. 1929. A preliminary report on the food of certain insect 

 feeding fishes of Lake Erie. MS., Department of Zoology, Ohio State 

 University, 30 pp. 



contained 82.9 percent Entomostraca and 17.1 

 percent fish by volume. 



The 61 walleyes captured July 2-18 had been 

 feeding entirely on fish fry. Yellow perch com- 

 prised 92.3 percent of the total volume. Seem- 

 ingly little other food was available to small 

 walleyes in this area at this season. Trawl catches 

 in which the walleyes were taken consisted of 

 99.0 percent O-group yellow perch. 



Young-of-the-year walleyes in other lakes of the 

 Midwest consume large quantities of yellow perch. 

 Eschmeyer (1950) found yellow perch in 42.1 

 percent of the stomachs of O-group walleyes of 

 Gogebic Lake, Mich., during June 24 to July 10, 

 1941. Yellow perch also made up 68 percent of 

 the total volume of food. Yellow perch constituted 

 77 percent by volume of the stomach contents 

 of O-group walleyes in Mille Lacs Lake, Minn., 

 in June-September (Maloney and Johnson, 1957). 



The 219 walleyes taken July 25 to August 7 

 had eaten a diversity of organisms. Yellow perch 

 continued to be the major food (total volume — 

 64.3 percent; frequency of occurrence — 72.3 per- 

 cent). They were also the most available prey 



Table 4. — Food of young-of-lhe-year walleyes in the Island region in June- November 1962 



i Volumes not measured in this collection . 



492 



U.S. FISH AND WILDLIFE SERVICE 



