TULLIBEE (JRGYROSOMUS TULLIBEE RICHARD- 

 SON) AS A FISH OF ECONOMIC 

 IMPORTANCE 



BY GEORGE WAGNER. 



(Presented hi/ Dr. E. A. Bmje of Madison. Wis.) 



For several years the State Geological and Natural History 

 Survey of Wisconsin has been engaged in a study of the fishes 

 of the state. Perhaps the chief result of this study so far has 

 been the recognition of the very general distribution of white- 

 fishes of the genera Coregonus and Argyrosomus through the 

 lakes of the state. The degree of variation among the forms 

 found has proven to lie very great, and much more collecting 

 will be necessary before a complete report can be made. It is 

 the intention here to discuss one species, certain peculiarities of 

 its distribution, and their relation to the economic importance of 

 the form. 



The Tuliibee, or Mongrel Whitefish (Argyrosomus tuUibee 

 Richardson) is a form chiefly known from Western British 

 America, although recorded from as far east as Lake Onondaga, 

 Xew York. Occasional specimens have also been taken in all 

 of the great lakes. As far as wo know, this is the first notice of 

 its occurrence in Wisconsin, or in any waters of the Mississippi 

 drainage basin. So far we have found the form in three lakes 

 of Wisconsin, which differ rather widely from one another in 

 their physical characteristics. It is now well understood tliat the 

 critical period for a lake, as far as its living organisms are con- 

 cerned, occurs in August, at the full establishment of the ther- 

 mocline. The conditions in these lakes at that time have l)een 

 well studied by Professor Birge and ^Ir. Juday of this survey. 



The lakes concerned are Kawaquesaga, at Minocqua in Onei- 

 da, county; North Twin Lake at Hackley; and Long Lake, 

 al)out four miles east of Hackley. Both of these last are in Vibis 

 county, and all three drain into the Wisconsin river, althougli by 

 very different routes. 



