Deep bottom 



•••••Crayfish 



Shallow bottom 



Greenside dorter •■•■ 



Fontoil darter 



Log perch 



... Croyfish 



• Beetle larvae- 



■•• Gammarus 



•■■• Baetinine mayflies- 



•■• Ephemera 



•"Coddisflies 



•tvlidge flies- 



Aquatic angiosperms- 

 Attached thallophytes < 



4 Detritus ■ 



FIG, 13-7 Food web in western Lake Erie, leading to the sheeps- 

 head fish. Species are separated into their different trophic levels. 

 The diagram would be even more complicated If other fish 

 species in the C. trophic level of the community had been in- 



ed. Although adult sheepshead are not preyed on by other 

 als, young during their first year serve as food for three or 

 other fish species (considerably modified from Daiber 1952). 



Food and feeding relationships 197 



