Mammals · Artiodactyla · Delphinidae

Commerson's Dolphin

Cephalorhynchus commersonii

Least Concern

The species is abundant and widely distributed; it faces no significant short-term risk. See full glossary

The piebald dolphin or tonina overa, also called Commerson's dolphin, is a species of odontocete cetacean of the family Delphinidae that lives in the waters of the southern hemisphere. It was first described by the naturalist Philibert Commerson, who was part of Baron de Bougainville's round-the-world expedition; later, the toninas overas were studied by the expert Francisco P. Moreno and also by the biologist Rae Natalie Prosser de Goodall.

Weight

35 kg – 60 kg

Size

1.3 m – 1.7 m

Lifespan

18 years

Diet

Carnivore

Feeds mainly on other animals.

Social structure

Herd

Lives in large groups as a strategy against predators.

Sighting difficulty

Easy

OceanFreshwaterCarnivore In herds Ocean Freshwater Mammal

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Fun facts

GeneralBlack and white like a miniature orca; it measures a little over 1.4 m.
It has two populations separated by some 8,500 kilometres of open ocean: one in Atlantic Patagonia and one in the Kerguelen Islands, in the middle of the subantarctic Indian Ocean, and the animals of each differ clearly in size and colour.
The calves are born grey and brown and only take on the black and white contrast of the adults after a few months.
Its strongly marked black-and-white pattern has earned it the names of panda dolphin and skunk dolphin; in South America it is known as the tonina overa.
It has two subspecies separated by 130 degrees of longitude and some 8,500 km, and nobody knows why: one at the tip of South America and another in the Kerguelen Islands, in the Indian Ocean. The Kerguelen one is larger, with less contrasting grey tones.
It is one of the smallest dolphins in the world: it does not exceed 1.7 m.
It seeks out areas of strong current. In the Strait of Magellan it prefers waters running faster than 15 km/h.
It swims inside and along the edge of the kelp forests, just like Peale's dolphin, with which it shares its range.
A 2022 study found that females are philopatric and males are the ones that disperse, a pattern that explains the genetic structure of its populations.