l8 UNIVERSITY OF COLORADO STUDIES 



a. Anal fin of more than 30 rays, its outer margin straiglit or slightly concave; color bluish or 



silvery, white below Ictalurus furcatus^ (LeSueur) 



aa. Anal fin of less than zg rays, its outer margin distinctly convex; color greenish, lighter below. 



Ictalurus punctalus (Rafinesque) 



Ictaltirus punctatus (Rafinesque) 

 White Cat, Channel Cat 



Silurus punctalus Rafinesque, Amer. Monthly Magazine, p. 358, 1818. 



Body stout but elongate, depth 4.5 to 5 in the length to the base of the 

 caudal; head small and rather conical, widest posteriorly, its length about 4 in 

 the length of the body; maxillary barbels long, usually reaching to beyond the 

 gill openings; mouth large and wide; dorsal fin with a spine, which is long, about 

 1 . 8 in the head, its posterior margin without teeth ; base of the dorsal spine nearer 

 to the tip of snout than to the adipose fin; adipose fin prominent and elevated, 

 its posterior margin free from the back; caudal fin deeply forked; pectoral fin 

 with one strongly serrate spine; tip of the pectoral fin reaching less than half-way 

 to the base of the ventral fin; anal fin short, its outer margin strongly convex, of 



24 to 2Q rays; lateral line prominent. 



Color above dark green or bluish green, sides paler shading to silvery below, 

 usually with several small dark spots; ventral parts grayish white with a yellow- 

 ish cast forward; fins opaque, often dusky or greenish. 



Size large, average adults weighing 4 to 10 pounds, very large individuals, 



25 pounds or more. 



Spawning season, latter part of May, June and early part of July. 



Range, rapid waters of the large streams of the Mississippi System, south to 

 the Gulf of Mexico, and the large rivers of northern Mexico. 



In Colorado this large catfish is found in the Platte and Arkansas rivers, 

 being fairly abundant in the latter during high water. With the decline of the 

 high water individuals are often left in the pools. At Julesburg, in the South 

 Platte River this fish is taken rarely during high water. In the Arkansas River 

 it is fairly common as far west as Fowler during high water. The removal of 

 water from the tributaries of the Arkansas for irrigation, as well as the introduction 

 of refuse from various mining industries, has restricted the channel cat to the 

 main stream in eastern Colorado. Several fishermen living along the Arkansas 

 report the charmel cat as at one time common in the Purgatory River, a stream 

 now almost without fish. 



Forbes finds the food of Illinois specimens of this species consists of vegetable 

 and animal debris, garbage, other fishes and almost anything likely to be taken 

 by a fish. 



' A channel cat; probably this species was reported to the writer by several fishermen as occurring 

 occasionally in the Rio Grande at Alamosa, Colorado, during high water. No specimens were seen, however 

 and the species is here included only in the key. 



