Trachinotus baillonii belongs to the carangid family (Carangidae). It is a species usually found in the surf zone along the sandy beaches of the Indian and Pacific Oceans. In the Indian Ocean this species is widely distributed except for the Persian Gulf where it is not present. In the Pacific Ocean, we can find it from Japan to Australia and up to the Marshall Islands.
The body of Trachinotus baillonii is elongated, oval and strongly compressed laterally. They reach lengths of up to 55 cm and weights close to 1 kg. The dorsal and ventral profile of the head are practically symmetrical and convex. Its snout is rounded, and both jaws have several bands of small villiform teeth. As for the fins, it has two separate dorsal fins, the first consisting of 7 short spines, and the second consisting of 1 spine and 21-25 soft rays. The anal fin has 2 independent spines, followed by a third spine attached to 20-24 soft rays. Both the first rays of the second dorsal fin and the initial rays of the soft portion of the anal fin are much longer than the rest of the rays and form distinctive lobes. The dorsal fin lobe is consistently shorter than the anal fin lobe. The pelvic fins are relatively short. The caudal fin is forked, with long lobes that can account for up to one third of the total length of the specimen. The lateral line is slightly irregular, and adopts a slight convex curve in the area of the pectoral fins, becoming straight later. This species has no scutes on the caudal peduncle.
The coloration of Trachinotus baillonii is bluish silver dorsally and silvery white ventrally. On the flank it has 1-6 black circular markings along the lateral line. These spots are absent in juveniles and as they grow the number of spots increases. It may have a different number of these spots on both sides of the body. In adults, these spots are smaller than the size of the eye itself. The color of the caudal, second dorsal and anal fins is gray with generally darker lobes. The pectoral fins are pale to dark yellow, and the pelvic fins are dark yellow to orange-yellow.