Figure 1. — Map of western Lake Erie showing locations 

 where young-of-the-year walleyes were collected and 

 areas by which data were analyzed. Dots represent 

 collection locations. 



were measured volumetrically by water displace- 

 ment in a cylinder graduated to 0.1 ml. Items 

 with a volume less than 0.1 ml. were listed as 

 "trace". The entire stomach contents of 176 wall- 

 eyes (41-74 mm. long) caught in June were ex- 

 amined with a dissecting microscope. No volu- 

 metric measurements were made of the food of 

 these fish. 



Counts were made of the O-group fish of the 

 following species that were caught in the trawl 

 hauls with the walleyes: Gizzard shad (Dorosoma 



cepedianum), ale wife (Alosa pseudoharengus) , 

 American smelt (Osmerus mordax), emerald shiner 

 (Notropis atherinoides) , spottail shiner (N. hud- 

 sonius), trout-perch (Percopsis omiscomaycus) , 

 white bass (Roccus chrysops), yellow perch (Perca 

 flavescens), and sheepshead or freshwater drum 

 (Aplodinotus grunniens). 



Data on food are presented separately for each 

 of three areas in which walleyes were collected 

 (fig. 1). Although the boundaries are somewhat 

 arbitrary, each area differs ecologically from the 

 others and each has its own characteristic fish 

 fauna. 



FOOD OF YOUNG WALLEYES IN DIF- 

 FERENT AREAS 



The food of young-of-the-year walleyes in Lake 

 Erie varied with geographic location and season 

 of capture, but, within an area and season, selec- 

 tion for certain species and sizes of prey was strong. 

 In general, little correlation existed between the 

 numbers of various forage species present in the 

 same catches with walleyes and the representation 

 of these species in walleye stomachs. 



Extreme Western Lake Erie (Area 1) 



Food organisms were found in 94.7 percent of the 

 189 walleye stomachs (table 1). Gizzard shad 

 and alewives were the principal food in July. 

 Together they made up 72.7 percent of the total 

 volume; gizzard shad occurred in 30.6 percent and 

 alewives in 20.7 percent of the stomachs contain- 

 ing food. These species represented only 4.1 per- 



Table 1. — Food of young-of-the-year wolleyes in extreme western Lake Eric in July, August, and October, 1962 



[Expressed in percentage of total volume (PV) and percentage frequency of occurrence (PO). Percentage frequencies based on numbers of stomachs containing 



food] 



490 



U.S. FISH AXD WILDLIFE SERVICE 



