Figure 3, — Northern brook lamprey (adult), Ichthyomyzon fossor . 



2. Ichthyomyzon fossor Reighard and Cummins, northern brook lamprey (adult) (fig. 3) 



The distribution of northern brook lampreys is widespread along the south shore of Lake 

 Superior with the exception of Luce and Alger Counties, Mich., where the American brook 

 lamprey, Lampetra lamottei , reaches its peak abundance. Inability to differentiate between 

 larvae of Ichthyomyzon unicuspis and Ichthyomyzon fossor impairs definition of the distribution 

 of these species. Adult northern brook lampreys have been collected from 24 streams, and 

 Ichthyomyzon larvae have been collected from 59. The traps at the electric barriers do not 

 retain adult northern brook lampreys. 



Records by state and county: 



Michigan - Chippewa 12, 14; Marquette 40, 46, 49, 50, 51, 53; Baraga 55, 57; Houghton 64, 

 65, 70; Keweenaw 71, 72; Ontonagon 94, 96, 97. 



Wisconsin - Ashland 131; Douglas 152, 153, 154, 155, 156. 



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