26 UNIVERSITY OF WISCONSIN STUDIES 



always lack. The results presented in this paper indicate that 

 as conditions in lakes approach those in rivers the number of 

 fishes per unit of area becomes fewer. Rivers are deserts among 

 aquatic habitats. They are of most value to fishes as highways 

 to lakes, swamps, and other aquatic Edens. 



In the following summary the fishes that were caught in the 

 writer's gill nets in two or more lakes are listed. Each species is 

 followed by the names of the lakes where it was caught, the 

 lakes being arranged in order according to the abundance of 

 the species in them. 



Yellow perch Wingra, Mendota, Michigan, Geneva, Pepin, Green. 



Pickerel Michigan, Green, Geneva, Pepin, Wingra, Mendota. 



Carp Mendota, Wingra, Pepin, Michigan. 



Rock bass Geneva, Green, Michigan, Mendota. 



Bluegill Wingra, Green, Geneva, Mendota. 



Ciscoes Green, Geneva, Mendota, Michigan. 



Largemouth black bass Wingra, Mendota, Geneva. 



Smallmouth black bass Geneva, Wingra, Green. 



Pumpkinseed Wingra, Geneva, Michigan. 



Common sucker Geneva, Green, Mendota. 



Black crappie Wingra, Mendota. 



White bass Mendota, Pepin. 



Black bullhead Michigan, Pepin. 



Long-nosed gar Wingra, Pepin. 



Wall-eyed pike Geneva, Mendota. 



The perch, bluegill, largemouth black bass, pumpkin- 

 seed, black crappie, and long-nosed gar were most abundant in the 

 shallowest and smallest lake (Wingra). The pickerel and black 

 bullhead were most abundant in the largest and deepest lake 

 (Michigan). The carp and white bass were most abundant in 

 the lake with the greatest degree of stagnation in summer, the 

 most varied shores, and the richest bottom fauna (Mendota). 

 The rock bass, smallmouth black bass, common sucker, and 

 wall-eyed pike were most abundant in the clearest lake with 

 the most rocky shores (Geneva). The ciscoes were most abun- 

 dant in the deepest inland lake which has rather clear water 

 (Green). No species of fish which is found in two or more lakes 

 is most abundant in the lake (Pepin) which is closely associated 

 with the great river. 



The yellow perch and pickerel are the only species which 

 were caught in gill nets in all of the six lakes studied. The perch 



