FISHES OF COLORADO IO5 



the top of the head; diameter of the eye about 5 in the head; middle of the pos- 

 terior margin of the operculum produced to beyond the origin of the pectorals, with 

 several irregular serrations; preoperculum strongly serrate posteriorly; nostril 

 small; mouth large and terminal, angle of the mouth reachmg to below the eye; 

 lower jaw very slightly if at all longer than the upper; premaxillaries protractile; 

 dorsal fins separate, the spinous dorsal the longer; spinous dorsal of XII to XIV 

 spines, its base almost twice the length of the pectoral, the first spine on a level with 

 the origin of the pectorals; soft dorsal of II or III spines and 12 to 14 rays, its base 

 shorter than that of the spinous dorsal, about equal to the length of the pectoral; 

 pectorals large, i. s to almost 2 in the head; ventrals about the same size as the 

 pectorals or slightly larger, inserted well forward, the base of the first ray of the 

 ventral a little more than the diameter of the eye from the base of the last ray of 

 the pectoral; anal short, higher than long, its base about one-half the length of the 

 pectoral, with II spines and 7 or 8 rays, base of the first spine posterior to the level 

 of the first spine of the soft dorsal; caudal large, not deeply forked, and somewhat 

 rounded, its greatest width very little less than the greatest depth of the body; 

 scales moderately large, ctenoid, with 6 or more prominent basal lobes, basal radii 

 5 to 7, circuli regular and concentric to the margin of the scale, apical third of the 

 scale with short strong teeth; lateral line complete, arched dorsally; scales 6 or 

 7) SS~70) 15 to 18; cheeks scaled. 



Color brassy yellow shading into olive-green dorsally, ventral parts almost 

 white; six or more vertical greenish bars four to ten scale series in width, extending 

 from the mid-dorsal region to within four to six rows of scales of the mid-ventral 

 line; top of the head bluish green; spinous dorsal dark grayish green, spines 

 lighter; soft dorsal and caudal greenish; ventrals and anal hyaline to white, rays 

 and spines yellowish to orange; pectorals greenish yellow. Size medium, length 

 of average adults 9 to 12 inches. 



The Yellow Perch ranges from Canada south into central Indiana and Illinois, 

 along the Atlantic Coast to the Neuse River, west into South Dakota. It has been 

 introduced with success into Montana and Colorado and the Pacific states. As a 

 native fish it is particularly abundant in the Great Lakes and adjacent waters. 

 This species is a general favorite with the common fisherman, since it will take 

 almost any sort of bait and its size and flavor make it a very desirable food fish. 

 In the Great Lakes it is caught more frequently perhaps than any other species. 

 The enormous number taken may be shown by the statement of the Michigan 

 Fish Commission that in 1908, 1,983,920 pounds of Yellow Perch were taken from 

 Saginaw Bay, Michigan, alone." The brightly colored ventral fins of this species 

 are often used as a fly-bait for bass and wall-eyed pike in the northern lakes. 



Perca flavescens is distinctly a lake fish. It is carnivorous, haunting the shore- 

 weed zone, although it is rarely taken in less than three feet of water. In large 



■ Leathers, Michigan Geol. Biol. Survey, Publ. 4, Biol. Ser. 2, p. 247, 191 1. 



