AMBLOPLITES — KOCK BASS 243 



AMBLOPUTES RUPESTRIS (Eafinesque) 



ROCK bass; redeye; goggle-eye 



(Map LXXIII) 



Raflnesque, 1817, Amer. Month. Mag., 120 (Bodianus). 



J. & G., 466; M. V., 115; B., I, 10; J. & E., I, 990; N., 37; J., 44; F., 69; F. F.. I. 

 3, 44; L., 23. 



Length 8 to 10 inches; body oblong, rather robust and only moderately 

 compressed; profile scarcely angled at nape; depth 2.2 to 2.5; greatest width 

 about 2 in greatest depth; depth caudal peduncle 1.12 to 1.20 in its length. 

 Color of upper parts olive, with black mottlings and brassy reflections; each 

 scale of sides with a central squarish black spot on band, these forming 

 longitudinal stripes traversing length of fish, being most prominent below 

 the lateral fine; belly bluish white with darker punctulations, forming a spot 

 on each scale; breast specked with fine black dots and with some blue, green, 

 or reddish; cheeks and opercles with brassy luster; a dark opercular spot; 

 iris maroon before and behind pupil, plum-colored above and below, and 

 edged with gold; median fins amber with brown mottlings (in handsome 

 irregular bars) and faint edgings of black; ventrals opaque whitish with 

 brown specks; pectorals transparent amber, dusky in males; young irregu- 

 larly barred and blotched with black. Head rather large, 2.6 to 2.8, the pro- 

 file little angled above eye; width of head 1.9 to 2.13 in its length; interor- 

 bital space 3.7 to 4.3 (usually under 4); eye 3.5 to 4; nose 3.4 to 4.1; mouth 

 large, obhque, maxillary past middle of orbit, 2.1 to 2.4 in head; a single 

 patch of teeth on tongue; operculum emarginate, the flap not prolonged; 

 gill-rakers few", 7 to 10, rather long, strong, and stitt. Dorsal XI (occasionally 

 XII), 10-12 (usually 10). rather long and low, its longest spine 3.25 to 3.5 in 

 head; length of base of dorsal about 1.4 times length of anal; caudal emar- 

 ginate; anal VI, 10-11; ventrals to vent or somewhat past it, sometimes 

 nearly to first anal spine in males; pectorals to first anal spine, 1.8 to 2 in 

 head. Scales 6 or 7, sometimes 8, 39-43, 11 or 12 (or 13); lateral line usually 

 complete; scales on cheeks in 7 or 8 rows. 



This large and handsome member of the sunfish family 

 reaches a length of a foot and a weight of a pound to a pomid 

 and a half, although its average weight probably does not exceed 

 half a pound. It is, with us, mainly a northern species, having 

 been taken from but four localities in southern Illinois, and not 

 at all in the lower Illinoisan glaciation. This limitation of its 

 range is accounted for by its decided preference for clear rocky 

 streams, its coefficient for swift water (3.66) being the largest 

 in our list of sunfishes. It has occurred to us most abundantly 

 in rivers of medium size (2.96), and about half as frequently 

 in creeks (1.44), its frequencies in other situations being com- 

 paratively insignificant. This peculiarity of local preference 

 tends to separate if from the other members of its family gener- 

 ally, with the exception of the small-mouthed black bass, 



