Jordan and Evermann. Fishes of North America. 1023 



464. PERCA (Artedi), LinntBus. 

 (RIVER PERCH.) 



Perca (ARTEDI) LINNAEUS, Systema Nature, Ed. x, 1758, I, and Ed. xn, i, 481, 1756, (fluviatilis) 

 Epitrachys, SCHULZE, Journ. Ber. Ver. Magdeburg, 1889, 209, (fluviatilis). 



Body oblong, somewhat compressed, the back elevated. Cheeks scaly; 

 opercles mostly naked ; the operculum armed with a single spine ; preop- 

 ercle and shoulder girdle serrated ; preopercle with retrorse, hooked 

 serrations below. Mouth moderate, terminal ; premaxillaries protractile ; 

 teeth in villiform bands on jaws, vomer, and palatines ; no canine teeth. 

 Branchiostegals 7. Gill membranes separate; pseudobranchiae small, 

 but perfect ; no anal papilla. Scales rather small, strongly ctenoid, 

 lateral line complete, the tube straight and not extending to the extremity 

 of the scale. Dorsal fins entirely separate, the first of 12 to 16 spines ; 

 anal fin with two slender spines, well separated from the soft rays; ven- 

 tral spines well developed, the ventral fins near together; caudal emar- 

 ginate; air bladder present. Pyloric ccecaS; vertebrae very numerous, 

 21 -f- 20 or 21 = 41 or 42. Fresh waters of northern regions ; three closely- 

 related species now known Perca fluviatilis in Europe, P. schrenkii in 

 Asia, and P. flavescens in North America. This genus has long been con- 

 sidered the type of the spiny-rayed fishes, and in many systems it has 

 been placed first in the series of fishes. Perca is, however, a compara- 

 tively recent and somewhat aberrant type, and in no sense entitled to be 

 regarded either as the first or the center of the spiny-rayed series. The 

 great group of Percoidea occupies in some sense a central position among 

 the Acanthopterygii and the characteristic spinous armature is here most 

 typical in character. But the genus Perca is neither central nor typical 

 among the Percoidea. That position is more properly to be assigned to 

 EpinepJielus. (rrepKij, Perca, the ancient name of Perca fluviatilis, from 

 Trep/cof, dusky.) 



1415. PERCA FLAVESCENS (Mitchill). 

 (YELLOW PERCH ; AMERICAN PERCH ; RINGED PERCH ; RACCOON PERCH.) 



Head 3i; depth 3J. D. XIII to XV-II, 13 to 15; A. II, 7 or 8; scales 

 7-74 to 88-17, 54 to 62 with pores. Back highest at origin of spinous 

 dorsal, which is more or less behind insertion of pectoral ; profile convex 

 from dorsal to occiput, thence concave anteriorly, the snout projecting, 

 a little longer than eye. Mouth somewhat oblique, maxillary not quite 

 reaching opposite middle of orbit. Gill rakers x -f- 15, the longest i to 

 f length of branchial filaments. Cheeks closely scaled throughout, the 

 scales imbricated ; opercular striae and rugosities on top of head well 

 marked. First anal spine longer than first dorsal spine; first dorsal 

 spine inserted above or a little behind base of pectoral. Pseudobranchiae 

 quite small. Gill rakers stout, shortish. Back dark olivaceous; sides 

 golden yellow ; belly pale ; sides with 6 or 8 broad, dark bars, which 

 extend from the back to below the axis of the body ; lower fins largely 

 red or orange ; upper fins olivaceous ; with or without a distinct black 



