The sheepshead porgy was first formally described in 1830 as Pagellus penna by the French zoologist Achille Valenciennes with its type locality given as Brazil.

[2] The genus Calamus is placed in the family Sparidae within the order Spariformes by the 5th edition of Fishes of the World.

The dorsal profile of the head is smoothly convex and is not all that steep and the snout is blunt.

There is occasionally a bluish-gray stripe below the eye as well as a dark brown bar, The upper base of the pectoral fin has a blackish spot.

[1] This species is found in clear reef areas between 3 and 87 m (9.8 and 285.4 ft) over soft or rubble seabeds.