68 FISHES OP ILLINOIS 



breed in the spring, depositing their eggs in great numbers 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 spawning behavior. They proceed 

 shoreward in shallow water to deposit 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 Mississippi 

 -Valley, 11,491,000 lb having been taken from the Mississippi 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 lb. 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 J 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 J in length bubalus. 



ICTIOBUS CYPRINELLA (Cuvier & Valenciennes) 

 (red-mouth buffalo ; big-mouth buffalo) 



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 21 feet and a weight of 40 lb, 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 



