68 FISHES OF ILLINOIS 



bers near the edges of sloughs. Fishermen on the Illinois say 

 that their set-nets become coated with eggs when spawning is in 

 progress. All species spawn early, ordinarily in April. Mosher 

 (Bull. U. S. Fish Comm., 1885, p. 190) has described their spawn- 

 ing behavior. They proceed shoreward in shallow water to de- 

 posit their eggs, each female forming the center of a bunch of 3 

 to 8 males. The oviposition is attended with a tremendous 

 splashing, which on a still evening may be heard a mile. The 

 people call it tumbling; in fact it is a sight which once seen 

 will never be forgotten. 



Buffaloes form a large part of the fish catch in the Missis- 

 sippi Valley, 11,491,000 Ib having been taken from the Missis- 

 sippi and its tributaries in 1903. The annual product of the 

 Illinois River and its tributary streams, although decreasing 

 considerably during the past twenty years, is now about 3,000,- 

 000 Ib. The flesh of the buffalo, while perhaps superior to that 

 of the carp, is not much more esteemed, and brings a low price. 



KEY TO THE SPECIES OF ICTIOBUS FOUND IN ILLINOIS 



a. Mouth large, oblique, upper lip about on level with lower margin of orbit, 



angle of mandible with horizontal more than 40; maxillary as long as snout; 



lips thin and nearly smooth cyprinella. 



aa. Mouth smaller, little oblique, level of upper lip about midway between chin 

 and lower margin of orbit, angle of mandible with horizontal slight, less 

 than 20; maxillary not more than % length of snout; lips more or less 

 coarsely striate. 



b. Back scarcely elevated, depth 3 to 3% in length urus. 



bb. Back elevated and compressed, depth 2% to 2% in length bubalus. 



ICTIOBUS CYPRINELLA (CUVIER & VALENCIENNES) 



RED-MOUTH BUFFALO; BIG-MOUTH BUFFALO 



(MAP IX) 



Cuvier & Valenciennes, 1844, XVII, 477 (Sclerognathus). 



G., VII, 24 (Sclerognathus); J. & G., 114 (bubalus); M. V., 44; J. & E., I, 163; N., 



49 (bubalus); J., 65 (bubalus); F., 82; F. F., I. 2, 81 (bubalus), II. 7, 451 (cypri- 



nellus); L,., 11. 



Body elliptical, robust, dorsal outline but little more curved than ven- 

 tral; body compressed somewhat more above than below median axis, but 

 nowhere keeled, being rather broadly rounded at belly and nape; greatest 

 depth from 2.8 to 3.3 in length, usually 3. Size large, reaching a length of 

 2^ feet and a weight of 40 Ib. General coloration a dull brownish olive, 

 never silvery, fins dusky. In breeding dress top of head slate with a tinge 

 of greenish, cheeks and opercles olive-green; upper part of body, except in 

 front of dorsal, of a coppery tint ; region of median axis a pale green ; ventral 



