168 NORTHERN FISHES 



also on the front of the base of the dorsal fin. In breeding males the 

 head is black and there are three rows of large tubercles across the 

 snout. The dorsal fin has 9 rays; the anterior ray is thickened. The anal 

 fin has 7 rays. The scales are 6-45-5. The predorsal scales (about 23) 

 are small and crowded. The pharyngeal teeth are 4 — 4. This minnow 

 reaches a length of 4 inches. 



This species, which is an important forage minnow, ranges from 

 Winnipeg through the Great Lakes region to Quebec and southward to 

 Virginia and the Gulf States. It is more common than the preceding 

 species in small brooks and pools. It is widely distributed over Minne- 

 sota in lakes and streams, especially in the central and southern part. 

 It occurs in the Lake of the Woods drainage (Evermann and Latimer. 

 1910). Greene (1935) found it widespread in Wisconsin and reported 

 it from the Lake Superior. Lake Michigan, and Mississippi River 

 drainages. 



Spawning occurs from early May until late June. With its tail the 

 male fans out a cavity under a stone or board. The female deposits the 

 eggs in the cavity, and the male guards them. 



GENUS Campostoiiia Agassiz 



CENTRAL STONEROLLER (Doughbelly, Rotgut Minnow, 



Stonelugger) 



C am/postoTna anovialum pulluvi (Agassiz) 



The central stoneroller (Figure 24C) is a pale-brown minnow with a 

 dark bar behind the opercles and across the dorsal and anal fins, which 

 are bright orange in spring males. The hps are thick and fleshy. The in- 

 testine is very peculiar; it is wrapped many times around the swam 

 bladder. The scales are 7, 49-55, 8. The dorsal fin has 8 rays, the anal 

 fin 7. The teeth are 4 — 4. This species reaches a length of 8 inches. It 

 is a bottom feeder living largely on vegetable matter. Forbes and 

 Richardson (1908) reported finding large quantities of mud in the 

 intestine. 



The central stoneroller occurs from Minnesota eastward through the 

 Great Lakes region and southward in the Mississippi Valley to Mexico. 

 In Minnesota it is more common in the central and southern parts. It 

 has been reported from the Minnesota, Blue Earth, and Pomme de 

 Terre rivers (Cox, 1897) and from the Root and White Water rivers 

 (Surber, 1920) . It is common in southern Wisconsin (Greene, 1935) . 



The largescale stoneroller, Campostoma anomaluTn oligolepis Hubbs 

 and Greene, may occur in Minnesota, though no Minnesota material 

 has been identified as this subspecies. It differs from the central stone- 

 roller in having 43 to 47 scales in the lateral line. Greene (1935) found 

 this subspecies common in many parts of Wisconsin and reported it also 

 from eastern Iowa. 



