238 FISHES OF ILLINOIS 



Key to Species of POMOXIS found in Illinois 



a. Dorsal spines typically VI, rarely V or VII; dorsal distance 1.7 to 1.9 in 

 length, a line drawn from back tip of maxillary at right angles with an- 

 terior margin of premaxillary crossing back in front of first dorsal spine; 

 body more slender and profile more strongly S-shaped that in P. sparoides 



color light, the dark markings tending to form rings annularis. 



aa. Dorsal spines typically VII or VIII, rarely VI, or IX, or X; dorsal dis- 

 tance 1.8 to 2, the line from back of maxillary crossing behind third or 

 fourth, or even fifth or sixth, to last dorsal spine; color dark, spotted, the 

 dark markings not forming rings sparoides. 



POMOXIS ANNULARIS Rafinesque 

 (white crappie) 



Rafinesque, 1818, Amer. Month. Mag., 41. 



J & G., 464; M. V., 115; B., I. 7 (sparoides, part); J. & E., I, 987; N., 37; J., 47; 

 F., 69; F. F. I. 3, 56; L„ 23. 



Length 12 inches; body elongate, compressed and back elevated; 

 the profile long and quite strongly S-shaped ; depth 2 . 2 to 2 . 6 in length ; 

 greatest width about 2.75 in greatest depth; depth caudal peduncle 1 . 1 

 to 1 .3 in its length. 'Color silvery olive, mottled with dark green, the 

 dark marks chieflv on the upper part of the body and having a ten- 

 dency to form narrow vertical bars; general color much lighter than in 

 the next species ; dorsal and caudal fins marked with green (rather than 

 blackish, as in the next species) ; anal pale, nearly plain ; a dusky opercular 

 spot' (J. & E. with emendations). Head long, 2 . 8 to 2.9; width of head 

 2 . 5 to 2 . 8 in its length ; interorbital space 4.3 to 5.6, convex ; eye 4 . 5 

 to 5 in head; nose 3.2 to 4.2, noticeably longer than in the next species and 

 also visibly longer than eye; mouth large, oblique, maxillary past mid- 

 dle of orbit, 2.1 to 2.3 in head. Dorsal typically* VI, 15, the fin in- 

 serted further from muzzle than in the next species, the dorsal dis- 

 tance! in the present species being 1.68 to 1 .88 in the length ; caudal 

 lunate; anal VI (occasionally V), 17-19; ventrals past first anal' spine; 

 pectorals 1 . 3 to 1 . 7 in head. Scales 6, 43-48. 12 ; lateral line developed 

 on most or all scales. 



The white crappie and the species following are commonly re- 

 garded in this state as the best for food of the starfish family, with 

 the exception of the black bass. The present species occurs in all 

 parts of the state, most abundantly in lakes, ponds, and bayous, but 

 commonly also in the smaller rivers and in creeks. It seems to have 

 no marked local or ecological preferences to embarrass its entrance 

 upon any waters containing its means of subsistence. It enters 



*Of 337 specimens of the present species examined, 318 had VI dorsal spines, 

 15 had V, and 4 had VII; of 315 specimens of Pomoxis sparoides, 266 had VII 

 spines, 46 had VIII, 2 had VI, 1 had IX, and 2 had X. 



fin two typical specimens of exactly the same length (6 inches), one annularis 

 and one sparoides, the dorsal distance differed 8 tenths of one centimeter. This 

 difference may be said to be due to difference in length of fins, the dorsals in both 

 species terminating at the same distance from the end of the last vertebra. 



