FISHES OF CHESAPEAKE BAY 
213 
110. Poronotus triacanthus (Peck). Butterfish; “Butter;” Harvest fish; Dollarfish. 
Slromateus triacanthus Peck, Memoir., Amer. Ac., II, Part II, 1800, p. 48, PI. II, fig. 2; Piscataqua River, N. H. 
Poronotus triacanthus Uhler and Lugger, 1876, ed. I, p. 114; ed. II, p. 96; Jordan and Evcrmann, 1896-1900, p. 2849, PI. CL, 
fig. 405. 
Stromateus triacanthus Bean, 1891, p. 88. 
Rhombus triacanthus Jordan and Evcrmann, 1896-1900, p. 967, PI. CL, fig. 405. 
Head 3.35 to 4.3; depth 1.7 to 2.1; D. Ill, 44 to 46; A. Ill, 40 to 42. Body moderate^ ovate, 
strongly compressed; dorsal and ventral outlines about evenly rounded; head short, deep; snout 
blunt, 3.25 to 4.5 in head; eye 3 to 4.05; interorbital 2.55 to 2.85; mouth moderate, oblique, slightly 
Fig. 120 .—Poronotus triacantlms 
superior; maxillary failing to reach eye, 2.15 to 2.45 in head; teeth present in jaws, feeble; gill rakers 
short, 15 to 17 on lower limb of first arch; scales small, thin, more or less deciduous; lateral line 
running high, following the curvature of the back; a row of conspicuous pores on back near base of 
dorsal; dorsal and anal similar, little elevated anteriorly, the spines small; caudal fin deeply forked; 
ventral fins wanting; pectoral fins long, 2.95 to 3.15 in length of 
body. 
Color silvery blue or gray above; sides paler, with numerous 
irregular dark spots, prominent when the fish is seen swimming 
in the water, but fading completely after death; silvery below; 
pectoral fins plain, with dusky axil, other fins pale to dark gray, 
sometimes slightly dusky. 
Fig. 122. — Larva 1 day old; 2.1 millimeters 
This species is represented by many specimens, ranging from 20 to 235 millimeters (M to 9M 
inches) in length. This butterfish is readily distinguished from Peprilus alepidotus (the only other 
“butterfish” of Chesapeake Bay) by the more elongate body and the lower dorsal and anal fins, 
which are scarcely elevated anteriorly. The young of this species do not differ greatly from the 
adult. The pores, situated along the back near the base of the dorsal, which are very conspicuous 
in the adult, are not very noticeable until the fish reaches a length of about 50 millimeters. 
It is of interest, as an illustration of the severe mutilations which fish sometimes overcome, 
to mention that we have at hand a specimen 205 millimeters in length, which met with an accident, 
