51] STUDY OF SOUTHERN WISCONSIN FISHES— CAHN 51 



lies, keeping the water in circulation and sediment in motion until the eggs 

 hatch. Thereafter the male accompanies the swarm of tiny bass for a 

 period of about two to three weeks, protecting them against the ravages 

 of larger fish. The food of the young fish is almost exclusively entomostraca, 

 but they begin their piscivorous habits when about an inch long, eating 

 young shore minnows, darters, etc. The adults are almost exclusively 

 fish-eaters, crayfish playing only a very minor role in their diet. Unlike 

 the red-eye, the green bass is active all winter and hundreds are caught 

 through the ice on most of the larger lakes. At this time of the year they 

 inhabit water 10 feet or less in depth and are associated with the silverbass 

 (Pomoxis sparoides) which are caught in the same holes. The greenbass 

 bites best on chubs (H. kentuckiensis and S. atromaculatus) but will also 

 take frogs, crayfish or angleworms. An excellent table fish, prized next to 

 the red-eye. 



73. Scardinius erythropthalmus (Linn.). European Rudd; Pearl Roach. 

 In 1916, Mr. B. 0. Webster, at that time superintendent of hatcheries, 



now a member of the Wisconsin state conservation commission, went to 

 New York at the request of Mr. Fred Pabst of Oconomowoc, and obtained 

 from the New York Aquarium "several pails" of this species. These 

 fish were successfully brought back to Waukesha county and were planted 

 in Oconomowoc lake, where they are doing very well. At present there are 

 three sizes of fish in this lake, indicating two successful spawnings at least. 

 The fish have never traveled more than half a mile from the site of the 

 original planting, at the southeast end of the lake. Knowing the location 

 of the school in a general way, I have caught three specimens since 1918, 

 always on worms as bait. The food of these has been entomostraca, 

 aogether with insect larvae and small minnows, with a few snails (Physa) 

 tnd small clams (Pisidium). 



Family percidae 



74. Stizostedion vitreum (Mitchill). Wall-eyed Pike. 



An introduced species which has been abundantly planted in Golden, 

 Oconomowoc, La Belle, Forest, both Nashotahs and Nemahbins, Laura, 

 Pine, Pewaukee and Nagawicka lakes. Except during the spawning season 

 when they ascend the rivers, the pike is distinctly a lake fish within the 

 limits of the county, but in Rock river just over the boundary it is very 

 abundant. It inhabits the deep water off the bars, ordinarily in the vicinity 

 of weed beds. The fish are of a wandering disposition, here today and 

 there tomorrow, so that their capture is often rather difficult. They 

 spawn early in the spring, ascending the rivers for the purpose soon after 

 the ice goes out. In this respect they resemble the pickerel (E. lucius) 

 which they follow and are themselves followed by the various species of 

 suckers. The young wall-eyes return to the lakes rapidly after hatching 



