[Jordan and Evermann, 1896-1900, p. 1719.]
This species much resembles the orange filefish from which it differs chiefly in its somewhat more slender body (2 to 3 times as long as deep), longer dorsal fin (44 to 49 rays), longer anal fin (47 to 52 rays), shorter caudal fin (in small unicornfish the caudal is less than half as long as the body, while in young orange filefish it is more than half as long), and in color. The dorsal spine may be serrated in young fish, but it is smooth in adults.
The unicornfish is olive on head and body with light blue reticulations extending from the snout to the tail; in grown fish there are numerous small round black spots on the sides of the body.
Reaches a length of 3 feet.
Tropical seas; northward to South Carolina on the Atlantic Coast of America, and to Georges Bank as a stray.
Two specimens of this fish, 5 inches and 51/2 inches long, caught on the western edge of Georges Bank Sept. 15, 1930, by the schooner Old Glory, are the only ones that have been reported from the Gulf of Maine. A third, 5 inches long, was taken by Atlantis, south of Sable Island (lat. 40°55' N., long. 59°55' W.), August 18, 1941.