FISHES OF THREE WISCONSIN LAKES 27 



is distinctively a lake fish. Forbes and Richardson (1908) and 

 Evermann and Clark (1920) reached the same conclusion after 

 studying its habits in Illinois and Indiana. During the present 

 investigation it was found to be the most abundant species in 

 four of the six lakes studied. In Lake Mendota and Lake 

 Geneva perch are the dominant deep water fishes, and it is of 

 interest to note that the deeper water in both of these lakes 

 loses its oxygen during the summer. It has been shown (Pearse 

 and Achtenberg, 1920) that perch have unusual ability to 

 endure stagnant water and this doubtless enables them to 

 feed somewhat in deep water at all seasons. There is apparently 

 a limit to the depth to which perch will migrate, for in Lake 

 Michigan and Green Lake they are not found in the deepest 

 water where ciscoes are the dominant fishes. 



The pickerel is most abundant in the large, deep, clear lakes. 

 The carp appears to be most common in lakes with muddy 

 bottoms either in deep or shallow water and is rare in deep, clear 

 lakes like Geneva and Green. The rock bass reaches its maxi- 

 mum where there are the most rocks alongshore and is absent 

 from lakes like Wingra and Pepin. The bluegill is numerous in 

 the small, shallow lake, but also quite common in the two deep- 

 est and clearest inland lakes. The pumpkinseed has a somewhat 

 similar distribution. These two sunfishes are usually associated 

 with the margins of swampy areas. The ciscoes are most 

 abundant in deep lakes in which the lower water is cool in 

 summer. They are present in the lakes in which the deeper 

 water stagnates, but are less abundant. 



The largemouth black bass feeds more on fishes than its 

 smallmouth relative, which partakes more of insects. These dif- 

 ferences probably account for the abundance of the former in 

 the lakes where shore fishes are most numerous, and of the latter 

 where insects abound. The common sucker reaches its maxi- 

 mum in the clear deep inland lakes. The black crappie was 

 caught in the small shallow lake and in that with varied shores. 

 The white bass is in the lake with varied shores and in that con- 

 nected with a great river. The black bullhead was seldom 

 caught in gill nets on account of morphological peculiarities and 

 such catches probably have no significance. The long-nosed gar 

 is associated with rivers and with an abundance of small fishes. 

 The wall-eyed pike was caught in one of the deep, clear, inland 



