Commerson.s Dolphin
Cephalorhynchus commersonii

Other Names: Skunk Dolphin, Piebald Dolphin, Black-and-white Dolphin, Jacobite, Puffing Pig

Habitat: Inshore

Status: Locally common

Population: Unknown

Threats: Hunting/whaling and entanglement in fishing nets

Group Size: 1-3, occasionally in groups of 100 or more

Fin Position: Slightly behind center

Newborns: 22-30 in (55-75 cm), c.13 lbs. (6 kg)

Adults: 4 ¼-5 ¾ ft (1.3-1.7 m), 75-130 lbs. (35-60 kg)

Diet: Krill or other crustaceans, fish, squid or octopus, and other invertebrates

Teeth: 56-68 on top row, 52-70 on bottom row

Description

Dorsal fin:

- leading edge may be long and straight
- most fins have a slightly concave trailing edge
- tip less rounded in some individuals
- black area around dorsal fin

Flukes:

- concave trailing edges (variable)
- slight notch in middle
- slightly rounded tips
- broad, black flukes

Flippers:

- serrations along leading edge of left flipper (variable)
- black upper sides and undersides of flippers
- rounded flippers

Head:

- gently sloping forehead
- black, conical head
- white patch on throat

Other characteristics:

- stocky body
- black tail stock
- sharp demarcation between white and black areas
- black patch on underside varies in shape according to sex
- main body color white
-

Behavior

- fast swimmer and often active on or above the surface
- breaches frequently, often several times in a row
- sometimes seen swimming upside down and spinning underwater on its longitudinal axis
- may surf in heavy swell or even in breakers close to shore
- its erratic swimming pattern makes it hard to judge where it will surface
- usually breathes 2 or 3 times before diving for about 15 to 20 seconds
- often bow-rides and will swim alongside or behind vessels
- sometimes found with Peale.s and Black Dolphins and Burmeister.s Porpoises
- some populations may keep to quite well-defined territories
- probably forages on or close to sea floor

Distribution

- distribution appears to be continuous along the South American coast from Peninsula Valdés, Argentina, to Tierra del Fuego
- also occurs in Chilean waters south of 51° S and around the Falkland Islands and Kerguelen Island, and there are scattered records from waters south of Tierra del Fuego
- an earlier record from South Georgia in unreliable
- appears to be most common in southern Tierra del Fuego, around the Falklands (especially near harbors and natural protected areas), and in the Straits of Magellan
- most sightings are close to shore, in water less than 325 ft (100 m) deep
- found along open coast and in fjords, bays, and river mouths; known to enter rivers
- seems to prefer areas with a large tidal range, often near kelp beds


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This page was created by:Candice Orca Mottet