The most distinctive feature of the pantropical spotted dolphin is, as its name suggests, the spots that speckle the body of adults. Newborn calves are unspotted, but by adulthood, a varying amount of light spots cover the upper surface, and dark spots cover the dolphin's underside (2). Underneath this spotting, the slender, stream-lined body is grey, with a darker grey cape extending back from the head and sweeping low underneath the dorsal fin (2) (4). The dorsal fin is narrow and sickle-shaped (4). The long, thin beak of the pantropical spotted dolphin is separated from the melon by a distinct crease (2) (4). In most adults, the tip of the beak is white (2). Male pantropical spotted dolphins are slightly larger than females (2). A subspecies of the pantropical spotted dolphin is recognised, Stenella attenuate graffmani
, which inhabits more coastal areas and can be distinguished in appearance by its larger, stockier body, thicker beak and more extensive spotting (4).