KISHES OF CHESAPEAKE BAY 
221 
KEY TO THE SPECIES 
a. Breast naked, except for a small triangular patch of scales immediately in front of ventrals; 
opercular spot prominent hippos, p. 221 
aa. Breast fully scaled; opercular spot present or wanting. 
b. Body rather slender, the depth 3.45 to 4 in length; gill rakers numerous, 24 or 25 on lower 
limb of first arch crysos, p. 222 
bb. Body moderately deep, the depth 2.25 in length; gill rakers fewer, 14 on lower limb of first 
arch latus, p. 223 
115. Caranx hippos (Linnseus). Jack; Crevalle; Runner; “Jenny Lind;” “ Rudder fish.” 
Scomber hippos Linnaeus, Syst. Nat., ed. XII, 1766, p. 494; Charleston, S. C. 
Carangus hippos Uhler and Lugger, 1876, ed. I, p. 113; ed. II, p. 94. 
Caranx hippos Jordan and Evermann, 1896-1900, p. 920, PI. CXLI, fig. 387. 
Head 3.3 to 3.7; depth 2.2 to 2.55; D. VIII-I, 20 or 21; A. II— I, 16 or 17; lateral scutes 26 to 30 . 
Body rather robust, compressed; upper profile anteriorly very strongly convex; head short and 
deep; snout very blunt, 3.65 to 4.5 in head; eye 3.3 to 4.25; interorbital 2.95 to 3.65; mouth 
slightly oblique, terminal; maxillary reaching about middle of eye in young, nearly or quite to pos- 
terior margin of eye in adult, 2.1 to 2.45 in head; teeth present on jaws, vomer, palatines, and tongue, 
some of the teeth on anterior part of lower jaw enlarged; gill rakers about half the length of eye, 
Fig. 129 — Caranx hippos 
13 to 15, besides rudiments, on lower limb of first arch; scales small, cycloid, not present on breast, 
except for a small patch immediately in front of ventrals, not present on second dorsal and anal, 
except on elevated portions; lateral line with a long low arch anteriorly, usually slight!}' shorter than 
straight portion; lateral scutes strong posteriorly, forming a strong keel on caudal peduncle; first 
dorsal with slender spines; second dorsal and anal similar, moderately elevated anteriorly; caudal 
fin very broadly forked; ventrals moderate, inserted a little behind base of pectorals; pectorals 
long, falcate, 2.9 to 3.4 in length. 
Color bluish green or greenish bronze above; lower parts pale silvery, sometimes with yellow 
blotches; a distinct black spot on opercle; fins usually more or less yellowish; spinous dorsal and 
elevated portion of soft dorsal distally dusky; ventral fins partly white; axil of pectoral dusky; 
the lower rays with a black blotch in adults, indistinct or wanting in young. Very young with 
five or six dark cross bars. 
This species is represented by 15 specimens in the present collection, ranging from 115 to 195 
millimeters (44^ to 7% inches) in length. The species differs from others of the genus in having the 
breast naked, except for a small triangular patch of scales just in advance of base of ventrals. 
This fish is carnivorous and apparently highly predatory of other fish, fish remains only occurring 
in the contents of six stomachs examined. The spawning habits are entirely unknown. 
