218 
BULLETIN OF THE BUREAU OF FISHERIES 
112. Seriola dumerili (Risso). Amber fish; Rubber jack; Rudder fish; Shark pilot. 
Cur am dumerili Risso, Ichthyol., Nice, 1810, p. 175, PI. VI, fig. 20; Nice. 
Scomber zanatus Mitchiil, Trans., Lit. and Phil. Soc., N. Y., 1815, p. 427; New York. 
Seriola zonata Jordan and Evermann, 1896-1900, p. 902, Pi. CXXXIX, fig. 381. 
Seriola lalandi Cuvier and Valenciennes, Hist. Nat. Poiss., IX, 1833, p. 208; Jordan and Evermann, 1896-1900, p. 903, PI. 
CXL, fig. 382. 
Seriola dumerili Jordan and Evermann, 189G-1900, p. 903. 
Head, 3.25 to 3.65; depth, 3.15 to 3.85; D. VI to VIII-I, 34 to 39; A. II, 18 to 20; scales about 
150 to 180. Body elongate, not greatly compressed; head rather large; snout long, tapering, 2.45 
to 2.85 in head; eye, 4.4 to 5.8; mouth large, terminal, a little oblique; maxillary broad, reaching 
about middle of eye, 1.95 to 2.25 in head; teeth small, in broad villiform bands on jaws, vomer, 
palatines, and tongue; gill rakers about the length of eye, 10 to 12 on lower limb of first arch; lateral 
line anteriorly scarcely arched, unarmed, in a keel on caudal peduncle; first dorsal composed of 
low, weak spines; second dorsal very long, elevated anteriorly; caudal fin broadly forked, the lobes 
of about equal length; anal fin shaped like the second dorsal, but much shorter; ventral fins large, 
longer than the pectorals, inserted nearly under base of pectorals; pectoral fins short, 1.9 to 2.25 
in head. 
Color grayish or purplish, with golden reflections, above; a bronze stripe along sides from snout 
to caudal; pale or white below; fins pale or dusky, pectoral, dorsal, and caudal yellowish. Young 
with dark bars along sides, these bars disappearing with age. Color in alcohol bluish gray above, 
pale underneath; dorsal fins dark; other fins mostly pale or dusky. The longitudinal band, when 
present, is dark. 
This fish was observed only twice during the present investigation and no specimens were 
preserved, because of their large size. It is here described from specimens collected at Beaufort, 
N. C., ranging in length from 205 to 440 millimeters (8 to 17J4 inches). One of us (Hildebrand) 
has examined a large number of specimens of this genus from various localities and has found great 
difficulty in separating species. It seems probable that too many species have been recognized. 
One of the specimens observed in the Chesapeake was recognized as S. zonata, the banded form, 
and two larger specimens, each weighing 16 pounds, were thought to be S. lalandi. It seems highly 
probable that S. zonata merely represents the young of S. dumerili and S. lalandi. The three are 
considered identical in this work. 
This fish apparently seldom enters Chesapeake Bay and is known only from the lower sections 
of the bay, where only a few fishermen appear to have seen it. A 16-pound fish taken at Lynnhaven 
Roads with a pound net and displayed in the Norfolk fish market caused much comment because 
of its size and rarity. Various names were suggested for it, including “salmon,” but no one seemed 
to recognize the fish. On the same day (June 16, 1921) another 16-pound fish was taken in a pound 
net off Back River. Evidently a small school, composed of fish of about equal size, entered the bay 
at this time. No others were seen during 1921 and 1922. 
Some of the rudder fishes reach a large size and are valued as food. This species reaches a 
maximum weight of 100 pounds. At Key West amber fish weighing 20 to 70 pounds occur irregu- 
Fig. 127 . — Seriola dumerili 
