FAMILY PERCIDAE 219 



Ohio River drainages and A. clara in the Mississippi River system 

 from Minnesota southward. 



Specimens of the sand darter taken in Big Sandy Lake, Minnesota 

 appeared to be hving to a great extent on small insects and Crustacea, 

 chiefly Chironomid larvae, Corixa, and Hyalella (Kidd, 1927) . 



GENUS Boleosoma De Kav 



CENTRAL JOHNNY DARTER 



Boleosoma nigrum nigrum, (Rafinesque) 



The body of the central Johnny darter is slender and fusiform. The 

 lateral line is often incomplete behind. The head is long, with a decurved 

 snout and a small mouth. The scales number 5-50-9. The cheeks are 

 nearly always naked; the breast is naked; the opercles are scaly. The 

 dorsal fin has 9 spines and 12 soft rays, the anal fin 1 spine and 8 soft 

 rays. The color and markings are usually pale olive, but sometimes the 

 markings are entirely black; the back is speckled with brown; the sides 

 are covered with numerous W-shaped blotches. The Johnny darter 

 reaches a length of 2 1/2 inches. 



This darter ranges from Saskatchewan to western Quebec and south- 

 ward west of the Alleghenies to Oklahoma and Virginia. It is more 

 common in and more widely distributed over Minnesota than any of the 

 other darters. It occurs in both lakes and streams. There are specimens 

 in the University of Minnesota collections from over 125 localities. 

 Greene (1935) reported it as widely distributed over Wisconsin. 



Midge larvae, Hyalella, and Entomostraca, with a considerable per- 

 centage of algae, constitute the principal food of this species. 



SCALY JOHNNY DARTER 



Boleosoma nigrum eulepis Hubbs and Greene 



The scaly Johnny darter (Figure 40E) differs from the typical form 

 principally in having the breast, nape, and cheeks fully scaled. Hubbs 

 and Lagler (1941) reported this subspecies as occurring in glacial lake 

 districts of portions of Minnesota, Iowa, Wisconsin, and northern 

 Illinois; eastward through the Great Lakes basin, but only in and about 

 the base-level lakes marginal to Lake Michigan in Wisconsin, Indiana, 

 and both peninsulas of Michigan, in Lake St. Clair and the Detroit 

 River, and in the bays and around the islands of Lake Erie in Ontario, 

 Ohio, and Pennsylvania. In Minnesota this subspecies has been found 

 only in the northern part, mostly in glacial lakes. It is the subspecies 

 found in the Lake Superior drainage. Many intergrades between this 

 subspecies and B. nigrum nigrum occur in central and southern Minne- 

 sota. 



