134 NORTHERN FISHES 



smalle'r tributaries of the Mississippi. It was secured in the Mississippi 

 River at Homer by Surber in 1915, but is very uncommon there. Greene 

 (1935) reported it from the Mississippi River at and below Lake Pepin 

 and from the St. Croix River and several other tributaries of the Mis- 

 sissippi River in Wisconsin. 



GENUS Moxostoma Rafinesque redhorses 



These are suckers of large size, with large, coarse scales (less than 55) 

 and bright coloration. They frequent clear streams and lakes and are 

 among the first fishes to succumb to pollution or to continuously turbid 

 water. This susceptibility probably accounts for their disappearance 

 from many waters in southeastern Minnesota. Hubbs (1930) has made 

 a critical analysis of this genus, but not much study has yet been made 

 of the distribution of the various species in Minnesota. The genus is 

 widely distributed over North America. 



NORTHERN BLACK REDHORSE (Black Mullet) 

 Moxostoma duquesnii duquesnii (LeSueur) 



The northern black redhorse is a rather large fish reaching a length 

 of over 2 feet. In general form it resembles the other species of Moxo- 

 stoma. The eye is usually small, less than two-fifths the snout in adults. 

 The mouth is large. The scales number 42-49, but typically 44-47. The 

 rays of the pelvic fin usually number 10. The northern black redhorse 

 ranges from eastern Iowa to Pennsylvania and southward to Georgia 

 and Oklahoma. This species occurs in southeastern Minnesota. It was 

 collected by the Department of Conservation in 1945 from the Root 

 River and identified by Dr. R. E. Johnson. Greene (1935) reported it 

 from several areas in southern Wisconsin. 



GREATER REDHORSE 



Moxostoma ruhreques Hubbs 



. This is a large fish reaching a length of over 2 feet. In general shape it 

 is similar to M. anisurum but is usually not as deep. The least depth 

 of the caudal peduncle is much more than two-thirds its length. The 

 halves of the lower lip meet at a rather sharp angle. The mouth is 

 rather large. The head is longer than in M. aiireoluvi and squarish 

 when seen from the side, to]3, or front. In adults the head in contained 

 3.7 to 4.4 times in the length, and in young, 1 to 3 inches, it is contained 

 3.3 to 3.7 times in the length. 



The scales have dark spots or crescents on the scale bases. The caudal 

 fin is bright red; in adults the tip of the dorsal fin is whitish near the 

 margin. The eye is less than one-fourth the length of the head in young 

 and less than one-seventh the length of the head in adults. The dorsal 

 fin has from 11 to 15 ravs. The scales number 42-46. 



