Southern right-whale dolphin
The southern right-whale dolphin forms an anti-tropical species pair with the northern right-whale dolphin. Both species were so named because, like right whales, they lack dorsal fins. This is one of the least well-known species of dolphin, in part due to its preference for deep, oceanic waters and its distribution throughout the cool temperate sub-Antarctic waters of the southern hemisphere.
The southern right-whale dolphin has a streamlined, slender body with no dorsal fin, which makes it easy to identify. It has a short, well-defined beak, gently sloping forehead, and small, pointed, falcate flippers. The tailstock is extremely narrow and the small flukes have concave trailing edges. The beak and lower forehead are white, along with the belly and flanks. The back is black from just in front of the blowhole all the way down to the flukes. The dorsal side of the flukes are greyish with a black trailing edge, while the ventral side is white. The flippers are white with a dark trailing edge. Calves are greyish brown or cream, and develop the mature colouration with age. All black individuals have been documented throughout the species range as have hybrids with dusky dolphins. Southern right-whale dolphins are unmistakable as they are the only dolphin in the southern hemisphere lacking a dorsal fin however from a distance they may be confused with porpoising sea-lions or fur seals.
Southern right-whale dolphins generally travel in pods of less than 100 animals but may be seen in herds of more than 1,000 individuals. They are energetic swimmers and can be seen porpoising at high speeds, resembling a herd of penguins. They may bow-ride, and can be seen breaching, lobtailing, belly-flopping, and side-slapping. Southern right-whale dolphins feed on a variety of fish species and squid and are often seen associating with dusky and hourglass dolphins, and pilot whales.
Southern right-whale dolphins are found in a circumpolar band in the cool temperate waters of the southern hemisphere, north of the Antarctic Convergence. In recent years, southern right-whale dolphins have been hunted in Peru and Chile for human consumption as well as for bait in the crab fisheries. The species is also at risk from bycatch from other fisheries including the Chilean swordfish gillnet fishery. No abundance estimate exists for the southern right-whale dolphin and the IUCN categorises this species as ‘Data Deficient'.