178 



FISHES OF ILLINOIS 



ICTALURUS FURCATUS (Le Sueur) 



BLUE CAT; CHUCKLE-HEADED CAT; FULTON CAT 



Le Sueur, 1840, in Cuv. & Val., XV, 136 (Pimelodus). 



G., V, 103 (Amiurus); J. & G., 109; M. V., 39; J. & E., I, 134; N., 50; J., 66 (Ich- 



thaelurus furcatus, Amiurus nigricans [part]; F., 82 and 83, (furcatus, pondero- 



sus, nigricans [part]; F. F., II. 7, 456; L,., 9. 



Body slender, somewhat compressed, the back elevated, depth 4 to 4.5 

 in length; profile long, steeper than in the next species, the elevation 18° to 

 23° and the contour broken at the nape (the elevation from that point to 

 dorsal being greater than from snout to nape). Size large, reaching a weight 

 of over 40 pounds. Color bluish or slaty gray above, shading to silvery 

 below and almost white on belly; fins, especially the anal, frequently edged 

 with dusky; spots very few or entirely absent. Head small, wedge-shaped, 

 more angular than in the next species, its length 4 to 4.4, its greatest depth 

 5.2 to 5.6 in body; top of head and nape prominently convex, the back 

 subcarinate in front of dorsal, the skin thin and fitted closely over the bones; 

 mouth small, inferior, the lower jaw wholly included; lips thin; maxillary 

 barbels reaching past gill-opening; eye small, oval, lying on the median axis 

 of the body and nearer lower than upper surface of head; diameter of orbit 

 7.2 to 7.8 in head. Dorsal fin high, nearer snout than adipose, its distance 

 from snout 3 to 3.5 in length; the spine rather longer and more slender than 

 in I. punctatus, its length 1.5 to 1.7 in head; the posterior edge usually fur- 

 nished with well-developed retrorse teeth. Caudal deeply forked, the lobes 

 about equal. Anal fin long, of 30 to 35 rays, including rudiments, its base 

 about }A, length of body, the free margin straight or very slightly rounded. 

 Pectoral spine a little shorter than that of dorsal; humeral process 1.3 to 

 1.6 in length of spine. 



Fig. 50 

 Anal and caudal fins of Ictalurus furcatus. 



This species is found throughout the Mississippi Valley and 

 the Gulf states, being most abundant southward, and especially 

 so in the Atchafalaya in Louisiana, where one to two million 

 pounds are taken annually. It forms a large per cent, of the 



