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Commerson’s Dolphin


Scientific Name:
Cephalorhynchus commersonii
Length:
1.5 m (4.9 ft)
Weight:
86 kg (190 lbs)
Status:
edangered
Prey:
Schooling fish, squid, crustaceans and invertebrates

Physical characteristics

Has a black head and fluke, a white throat and body and a long dorsal fin that starts straight end ends in a curve.

Behavioral characterization

They are very active and are known to do many tricks in the water.

Distribution

Coastal waters off the coast of southern Argentina, around the Malvinas/Falkland Islands, off the south coast of Chile, and around the Kerguelen Islands in the southern Indian Ocean.

Population size

Unknown

Predators

There is no documented observation of predation; may include killer whales, sharks and leopard seals.

Migration/Dispersal patterns

Little is known about the migratory patterns of these dolphins, however fishermen report that they disappear from their common areas during the winter. They may follow fish that migrate offshore in winter. The dolphin population in the Strait of Magellan decreases in late autumn. In the Kerguélen population, the majority of dolphins migrate out of the Golfe du Morbihan between June-December.

Social system/Group size

They are highly social and are usually seen in groups up to 10. For feeding and breeding groups up to 100 gather; often together with Burmeister's porpoise, Peale's and Chilean dolphin.

Major threats

Entanglement in fishing gear and pollution are the major threats, but underwater noise (eg. from naval operations) is known to cause stress and might be a reason for strandings.

Research efforts

Several studies on the abundance, biology, reproduction, migration and behavior are conducted.

Fun fact

They are known to swim upside down in order to catch prey because they are not as visible.