The Atlantic moonfish is a slender, deep-bodied fish that is extremely compressed.

The Atlantic moonfish have a faint spot on the base of their pectoral fins.

Atlantic moonfish can be found in schools at the bottoms of inshore waters.

Western Atlantic: Nova Scotia, Canada, along coasts of Gulf of Mexico and South America, Argentina.

Selene setapinnis was formally described by the American ichthyologist Samuel L. Mitchill as Zeus setapinnis in 1815 with the type locality given as the Bay of New York, New York, U.S.A.[3] The generic name Selene is from the Greek for "moon", referring to the vague moon-shape of S. vomer while the specific name is a compound of seta meaning "bristle" and pinnis meaning "fin" and refers to the bristle-like points of the dorsal fin and the anal fin.