Pacific bonito head. The caudal peduncle is slender, and the body entirely scaled. It has no teeth on the vomer. It has a small keel on either side of the median keel on the sides of the caudal peduncle, and six to eight finlets on the dorsal and ventral surfaces of the caudal peduncle. The maximum length is about 40 inches and weight 25 pounds. It is found anywhere from inshore to about 100 miles offshore from northern Vancouver Island to Mexico, though it is not normally found north of Point Conception. It usually travels in schools. Fish and squid are its
Breitensteinia in five to six longitudinal rows on each side, a dorsal profile rising evenly but not steeply from the tip of snout to the origin of dorsal fin and then sloping gently ventrally from there to the caudal peduncle, a horizontal ventral profile to the origin of the anal fin and then rising to the caudal peduncle, a dorsal fin origin nearer to the tip of the snout than caudal flexure, and a truncate caudal fin. "B. hypselurus" has a smooth posterior edge to its dorsal fin spine, relatively tall neural spines on the caudal vertebrae, a shorter caudal peduncle,