276 FISHES OF ILLINOIS 



pyloric caeca 3 to 7; dorsal spines 12 to 16; anal with 2 slender spines, well 

 separated from the soft rays; scales rather small, ctenoid. Fresh waters of 

 northern regions; 3 closely allied species, one each in Europe, Asia, and North 

 America. 



PERCA FLAVESCENS (Mitchill) 



YELLOW perch; RINGED PERCH; AMERICAN PERCH 



(Map LXXXIV) 



Mitchill, 1814, Rep. Fish. N. Y., 18 (Morone). 



G., I, 59; J. i& G., 524 (americana); M. V., 134; B., I, 48; J. & E., I, 1023; N., 36; 

 J., 43 (americana); F. F., I. 3, 29 (americana); F., 63 (americana); L.., 26. 



Length 1 foot; body only moderately elongate, considerably compressed; 

 back elevated, highest in front of spinous dorsal; the profile convex from first 

 dorsal spine to occiput, thence straightish or slightly concave to muzzle; 

 depth 3.3 to 3.8; greatest width of body about ^/-j of its depth; depth caudal 

 peduncle 2 to 2.2 in its length. Color of sides and back brassy green to 

 golden yellow, with seven broad bars of dusky crossing each side from back 

 nearly to belly; belly whitish with reflections of green, salmon, and yellow; 

 iris brassy at edge ; spinous dorsal gray, usually with a black spot on last two 

 membranes; soft dorsal and caudal plain green; pectorals transparent grayish 

 green; ventrals and anal variously light grayish green or orange to crimson 

 according to season and habitat. Head 3 to 3.5; width head 1.8 to 2.1 in 

 length; interorbital space nearly flat, 3.8 to 4.3; eye 1.1 to 1.4 in interorbital, 

 4.5 to 5.5 in head; nose 3.4 to 3.7, longer than eye; maxillary to middle of 

 orbit, 2.4 to 2.8; opercle ending above in several coarse jagged points; pre- 

 opercle strongly serrate, especially below; gill-rakers X + 15, the longest 

 more than half length of branchial filaments; pyloric cseca 3. Dorsal XII to 

 XIV-II or III, 12 to 13; longest spine a little more than 2 in head; length 

 base of soft dorsal about % base of spinous; caudal lunate; anal II, 7-8; 

 ventrals more than half-way to vent; pectorals 1.6 to 1.9 in head. Scales 6 

 or 7, 57-62, 15-18; lateral line nearly or quite complete; cheeks scaled, in 

 about 8 to 10 rows. 



This is one of the best-known fishes in the northern part of 

 the state, swarming especially along the piers on the lake front 

 at Chicago, where it is the common game of the local fishermen. 

 It occurs elsewhere in Illinois mainly in the upland lakes of the 

 northeastern part of the state, in the tributary streams flowing 

 into Lake Michigan, and in the Illinois and Mississippi rivers 

 as far south as Meredosia. It is virtually unknown in the 

 southeastern half of the state, and has never once been taken by 

 us in any of the streams of the Wabash or Kaskaskia systems, 

 or from any of those farther south. It is inconstant in its abun- 

 dance in the Illinois River, and is said to have increased greatly 

 there since the opening of the drainage canal has cooled and 

 cleared the waters of that stream. 



