Rough – Toothed Dolphin

Appearance: relatively robust, elongated body. Relatively large eyes bulge from a narrow head that shows no demarcation or crease between the melon and the snout. The long, conical beak is continuous with the forehead. The head is also somewhat conical. These features give the rough-toothed dolphin a somewhat reptilian appearance.

Key Characteristicsrough-toothed-dolphin

  • Conical head and beak
  • No crease between melon and beak
  • Narrow dorsal cape
  • Large black eyes and white lips
  • White or pale pink sides
  • Large flippers set far back
  • Stocky body
  • High, wide dorsal fin
  • Skims the surface

Dorsal Fin: high and located centrally on the back. The leading edge of the fin is variable in shape and usually rises at 450 to body. The trailing edge is falcate.

Flippers: relatively large, and pointed, with a sickle-shaped leading edge. Set back further along the body than in similar dolphin species.

Flukes: broad with concave trailing edges, slightly pointed tips and a distinct median notch.

Teeth: faint ridges on the teeth give this dolphin its ‘rough-toothed’ appellation. Upper jaw:  40-52 teeth. Lower jaw:  40-56.

Colouration: The dorsal fin and prominent, narrow dorsal cape, which extends slightly down the flanks below the dorsal fin, are dark or bluish grey. Apart from the cape, the flanks are light grey. Darker markings extend over the black eyes to the upper flanks. The lips, throat and belly are white or pale pink. The tip of the beak is pale pink, and the lower body may be marked with irregular white or pink spots and blotches. Scarring is often seen.

Behaviour: tends to lethargy, but can be a fast, powerful swimmer when the occasion demands. Skims the surface and occasionally perform low breaches, but rarely porpoises or bow-rides. Individuals are sometimes seen swimming with the tips of their beaks and their cheeks out of the water. Groups often swim shoulder-to-shoulder when travelling.

Associates: melon-headed whale, Fraser’s dolphin, spinner dolphin, spotted dolphin, bottlenose dolphin.

Diet: cephalopods and fish, including large species such as mahi-mahi (Coryphaena hippurus).

Dive Depth: S.bredanensis is a deep diver, remaining submerged for up to 15min.

Distribution: a poorly known offshore species, mostly found in deep oceanic waters. Rough-toothed dolphins are rarely sighted at sea.

Sightings: uncommon. No evident seasonality.