Body is elongated and strongly flattened from side-to-side. Mackerel are green on the back, shading to silver on the sides with golden-yellow irregular spots found above and below the lateral line. Cero Mackerel have similar colors but spots are arranged in a row and cero have 1 or 2 longitudinal stripes that are the same color as the spots. They have a pronounced black spot on the front of the dorsal fin. Lateral line curves gently to base of tail. There are 16 to 18 spines in the first dorsal fin, 15 to 18 soft rays in the second dorsal fin with 8 to 9 finlets behind it, and 13 to 15 gill rakers on the first arch. Lacks scales on the pectoral fins.