Trachurus lathami

Common Name

Rough Scad

Year Described

Nichols, 1920


Dorsal Fin: 8 spines in first lobe, followed by I, 28-34 (last ray spaced widely from the rest of fin but connected with a membrane)
Anal Fin: 2 spines separate from rest, followed by I, 24-30 (last ray spaced widely from the rest of fin but connected with a membrane)
Pelvic Fin: I, 5
Gill Rakers: 12-16 upper, 33-41 lower; 46-54 total
Vertebrae: 10 precaudal, 14 caudal

Elongate and ovoid, with a large head and eye. Adipose eyelid well developed. Jaw extends to anterior margin of eye. Teeth in a single row in both jaws. Shoulder girdle margin with small furrow (no papillae). Pectoral fins shorter than head. Spiny dorsal fin higher than soft portion of fin (anterior lobe of soft dorsal higher). Anterior lobe of anal fin also higher. Tail deeply forked. Dorsal accessory lateral line extends rearward to the soft dorsal fin. Main lateral line with scutes along its entire length (total 61-77), although anterior scutes are often obscured with smaller scales. Small cycloid scales on entire body except behind pectoral fin.


Silvery to yellowish lower body, darkening to bluish, greenish, or gray on the upper head and back. Dark spot on upper opercle and a dark area above eye. Spiny dorsal dusky, soft dorsal clear basally and dusky at margin with a white tip to the anterior lobe. Caudal fin clear with dusky margin. Rest of fins clear.


Average size to 20cm. Maximum to 33cm.


Continental waters from the surface to 90m, usually near the bottom. Forms schools.


Widespread from Maine to Argentina, except for the Caribbean islands. The Chilean species T. murphyi does not appear to occur in the SW Atlantic.


Smith-Vaniz, W.F. 2003. Carangidae (pp 1426-1468). In: Carpenter. 2003. The living marine resources of the Western Central Atlantic v. 3.