Commerson’s Dolphin (Cephalorhynchus commersonii) is one of four dolphins in the Cephalorhynchus genus. This Dolphin species is also known as Skunk Dolphin and Piebald Dolphin.
This dolphin is found in two distinct areas: around the southern tip of South America, Tierra del Fuego, the Falkland Islands, and near the Kerguelen Islands in the southern part of the Indian Ocean.
The dolphin is named for Philibert Commerson, who first described them in 1767 after he sighted them in the Strait of Magellan.
Commerson’s Dolphin has a very distinctive patterning. It has a black head, dorsal fin, and fluke, with a white throat and body. The demarcation between the two colours is very clear-cut. In shape and size””the creature is stocky and grows to around 5ft. Its appearance resembles that of a porpoise, but its conspicuous behavior is typical of a dolphin. The dorsal fin has a long, straight edge which ends in a curved tip. The fluke has a notch in the middle. This dolphin has no beak.
Females reach breeding age at six to nine years. Males reach sexual maturation at about the same age. Mating occurs in the spring and summer. The oldest known Commerson’s Dolphin died at age 18.
Population and distribution
This dolphin species is in two locations. The larger population is found inshore in various inlets in Argentina, in the Strait of Magellan and near the Falkland Islands. The second population resides near the Kerguelen Islands. They prefer shallow waters. Global populations are unknown, but the species is accepted to be locally common. A survey in 1984 estimated there to be 3,400 individuals in the Strait of Magellan.
The Commerson’s Dolphin is very active. It is often seen swimming rapidly on the surface and leaping from the water. It also spins and twists as it swims and may surf on breaking waves when very close to the shore. It will bow-ride and swim behind fast-moving boats.
This dolphin feeds on a mix of coastal and pelagic fish and squid. Those in the South American sub-population supplement their diet with crustaceans.