40 ILLINOIS BIOLOGICAL MONOGRAPHS [40 



43. Eybopsis kentuckiensis (Raf.). Chub; Horny-head. 



One of the most abundant fish in the Ashippun, Bark and Mukwonago 

 rivers, together with their tributary streams. Formerly abundant in the 

 Oconomowoc river, but the numbers here are now greatly reduced. This 

 fine minnow, reaching a length of 6 and 7 inches, is, together with Semotilus 

 alromaculatus, to which it is superior for the purpose, the best casting 

 minnow, and tens of thousands of them are captured yearly for the purpose. 

 I personally know two guides who have taken not less than 600 of these 

 chubs a week for five months a year for more than forty years, from the 

 Ashippun river, and still the fish are abundant. This is to say nothing of 

 dozens of other bait catchers who also frequent this productive stream. 

 The fish breed in May and June, spawning over clear gravel in which a 

 nest is constructed of pebbles. I have frequently seen several females 

 spawning in the same bed, the construction of which is undertaken by the 

 horny-headed males. The chubs bite readily on hook and line, by which 

 method they formerly were captured for bait. However, the glass minnow 

 trap has superseded this method, and hundreds can now be caught in an 

 hour without injury to the fish. 



Order NEMATOGNATHI 

 Family siluridae 



44. Ictalurus punctatus (Raf.). Channel-cat. 



An introduced species which is in the process of establishing itself. 

 Since the reclamation service along the Mississippi has been functioning, 

 many of this species have been shipped in and planted in various lakes. 

 Thus Oconomowoc received about 700 fingerlings in August 1925, and other 

 plantings have been made in Nagawicka, Golden, Fowler and La Belle. In 

 1909 ten fish of this species, weighing about half a pound apiece were 

 planted in Nagawicka lake. In July, 1923, one was caught in that lake 

 weighing just under 5 pounds. I have no evidence to show whether or not 

 the species is breeding. 



45. Ameiurus natalis (Le Sueur). Yellow Bullhead. 



The characteristic bullhead of the Rock river and its tributaries, as 

 well as of most of the larger lakes. I have taken the species in Fowler, 

 Oconomowoc, La Belle, Okauchee, Pine, Nagawicka, both Nashotahs 

 and Nemahbins, Pewaukee, and Ashippun lakes. A lover of soft bottom 

 and heavy weeds, usually Potamogetons. Usually about }/$, to % of a pound 

 in weight, an occasional individual weighing 2 pounds is taken. The species 

 seem to do equally well in clear and muddy waters, lakes or rivers. The 

 fish are for the most part inactive during the day so far as feeding is 

 concerned, but they bite well as dusk approaches, and far into the night. 

 The fish spawn in the lakes in heavy banks of weeds; in the rivers usually 

 up under overhanging banks or at the entrance of deserted muskrat 



