226 
BULLETIN OF THE BUBEAU OF FISHERIES 
oblique forehead, and by the produced anterior rays of the second dorsal and anal. The young of 
this fish are proportionately shorter and deeper than the adults; the dorsal spines bear long fila- 
ments, which disappear with age; the ventral fins are greatly produced, becoming short in the 
adult; and the sides have four or more dusky cross bars, which later disappear. 
The moonfish is carnivorous. Six specimens examined had fed on small crustaceans and on 
fish. Each alimentary tract, also, contained a considerable amount of smooth sand. Its spawning 
habits are unknown. 
This species was observed in the southern part of the bay and only during September and October, 
when it was common and many were taken in pound nets and small numbers in large haul seines. 
During the period from September 23 to October 5, 1921, as many as 300 moonfish per day were 
caught in a set of two pound nets in Lynnhaven Roads. At Ocean View it was equally abundant. 
Our field records show that this fish was taken (1 to 15 individuals at a time) in 14 of a total of 32 
hauls made at Ocean View, Va., with an 1,800-foot seine from September 23 to October 27, 1922. 
One fish was only 90 millimeters long. All the others ranged from 117 to 187 millimeters (4J^ to 
l]/i inches) in length. A number of individuals also were taken in small collecting seines along the 
beaches at Cape Henry, Cape Charles, Ocean View, and Buckroe Beach. The following weights 
were secured: 3J4 inches, 0.5 ounce (1 fish); 4J^ inches, 0.9 ounce (2 fish); 5 inches, 1.1 ounces 
(1 fish); 5 H inches, 1.5 ounces (5 fish); 6 inches, 1.9 ounces (14 fish); 6H inches, 2.6 ounces (3 
fish); 7 inches, 3 ounces (5 fish); and 7Jdj inches, 3.5 ounces (2 fish). 
The moonfish is reported to reach a maximum weight of 2 pounds. In the Chesapeake fish 
weighing more than one-half pound are unusual, and virtually none are utilized in the markets. 
The moonfish is considered a good food fish in some parts of its range, notably at Key West, Fla., 
where one-half pound is a common size. 
Habitat . — Southern Massachusetts (rarely to Cape Cod and Casco Bay, Me.) to Uruguay. 
Chesapeake localities. — (a) Previous records: Mouth of Potomac River, “southern part of 
Chesapeake Bay,” and Cape Charles city. ( b ) Specimens in collection: Cape Charles, Buckroe 
Beach, Lynnhaven Roads, and Ocean View, Va. 
92. Genus VOMER Cuvier. Horsefishes 
Body broad, ovate, very strongly compressed; head short and deep, its anterior profile nearly 
vertical; snout projecting only slightly; teeth small, present on jaws, vomer, and tongue; palatines 
with weak teeth or none; scales small, rudimentary; lateral line anteriorly with a prominent arch, 
the straight part with small bony scutes, at least in adult; spines of first dorsal very short; soft 
dorsal and anal very low, never bearing produced rays. 
120. Vomer setipinnis (Mitchill). Moonfish; Sunfish; Horsefish. 
Zeus setipinnis Mitchill, Trans., Lit. and Phil. Soc., New York, 1, 1814, p. 384; New York. 
Vomer setipinnis Uhler and Lugger, 1870, ed. I, p. Ill; ed. II, p. 93; Jordan and Evermann, 1896-1900, p. 934, PI. CXLIV, 
fig. 392. 
Head 2.7 to 3.5; depth 1.2 to 1.8; D. VIII-I, 21 or 22; A. II-I, 17 or 18. Body rhombic, 
proportionately deeper in young than in adult, very strongly compressed; back much elevated; 
anterior profile very steep, concave in advance of eyes; head short and very deep; snout little pro- 
jecting, 2 to 2.4 in head; eye 3.5 to 3.95; interorbital 3.4 to 4.6; mouth rather large, oblique, slightly 
superior; maxillary broad, 2.2 to 2.9 in head; teeth small, present on jaws, vomer, and tongue; gill 
rakers usually somewhat longer than half the eye, 26 or 27 on lower limb of first arch; lateral line 
anteriorly with a prominent arch, somewhat shorter than straight part, posteriorly with small but 
distinct bony scutes; first dorsal with eight short, pungent spines; second dorsal and anal similar, 
very low, scarcely elevated anteriorly; caudal fin broadly forked; ventral fins very small, shorter 
than eye; pectoral fins rather long, falcate in adult, 2.55 to 3.7 in length of body. 
Color bluish green above, shading into bright silvery along sides; larger examples with an 
obscure dark bar, extending from tip of snout through eye to upper angle of gill opening; upper 
surface of caudal peduncle bluish black; some of the small specimens with a dusky spot on sides 
over the beginning of the straight part of lateral line; dorsal, anal, and ventrals plain; caudal green- 
ish yellow; pectorals fight yellow. 
