The fish exhibits a green back; its sides are silvery marked with about three rows of round to elliptical yellow spots. Lateral line gradually curving down from the upper end of the gill cover toward caudal peduncle. The first (spiny) dorsal fin is black at the front. Posterior membranes are white with a black edge. Its single row of cutting edged teeth in each jaw (around sixty-four teeth in all) are large, uniform, closely spaced and flattened from side to side. As with the King mackerel and the Cero mackerel, these teeth look very similar to those of the Bluefish, Pomatomus saltatrix.
Spanish mackerel occur seasonally from the Yucatán peninsula, Mexico, as far north as Cape Cod, Massachusetts. They are a shallow water species, preferring sand bottom in depths of 10 to 40 feet (3 to 12 m), occasionally found as deep as 80 feet (24 m).
It appears that one Atlantic and one or more Gulf groups of Spanish mackerel occur in Florida waters. With rising water temperatures, the Atlantic group migrates along the Atlantic coast of the United States from Miami Florida, beginning in late February through July reaching as far as southern Cape Cod, Massachusetts, then returning in fall. An Eastern Gulf group moves northward from the Florida Keys during late winter and spring, appearing off the central West Coast of Florida about April 1. Movement continues westward and terminates along the northern Texas coast. During fall, this group migrates back to its wintering grounds in the Keys.