(Peale, 1848) - Peale's dolphin
Distinctive Characteristics
The general body shape of Peale's dolphin is typical for dolphins of the genus Lagenorhynchus. Few specimens have been examined, but observations of Peale's dolphins suggest they are the most robust of the Southern Hemisphere dolphins of this genus. The dorsal fin is pointed and falcate.
Peale's dolphins share coloration pattern components with both dusky and Pacific white-sided dolphins. Peale's dolphins are greyish black above and white below. They have a curved flank patch of light grey with a single dorsal spinal blaze, or “suspender,” fading into the black of the back near the blowhole. A large pale grey thoracic patch extends from the eye to midbody; it is separated from the white below by a well-developed dark stripe. The stripe loops up above a small white patch under the flipper. The flippers are grey-black, and the dorsal fin is dark grey-black, with a thin crescent of light grey on the trailing margin. Most of the beak is dark grey to black.
Tooth counts for 3 specimens ranged from 27 to 33 on each side of each jaw.
Can be confused with
Peale's dolphins are most easily confused with dusky dolphins. The face, rostrum, melon, and most of the chin of Peale's dolphins are dark grey-black, as if encased in a mask. This feature, plus the well-developed black stripe below the thoracic patch, readily distinguishes Peale's dolphins from dusky dolphins.
Size
The largest specimen recorded was 2.16 m long, and adults are estimated to weigh about 115 kg. Length at birth is estimated to be about 1 m.
Geographical Distribution
Peale's dolphins are coastal animals, found in bays and inlets, around islands, and over the continental shelf. They are frequently seen close to shore and sometimes shoreward of kelp beds. Peale's dolphins are confined to South America, south to about the latitudes of Valparaiso, Chile, and south central Argentina. They are regularly seen around the Falkland Islands. One exceptional sighting was reported from Palmerston Atoll.
Biology and Behaviour
Peale's dolphins have been seen in small groups (5 to 30 are typical). Photo-identification studies have shown that some dolphins spend the entire year in limited areas close to shore, in the magellan strait. They frequently bowride, and will sprint to a ship's bow. At the bow, they often speed ahead, leap high into the air and fall back into the water on their sides, producing a large splash with a loud slapping noise.
Newborns have been observed in Magellan Strait as early as October.
Little is know of food and feeding habits; one animal collected in the Falkland Islands had recently consumed an octopus and others have been observed feeding on róbalo (snooks, family Centropomidae) and pejerrey (silversides, family Atherinidae).
Exploitation
Peale's dolphins are incidentally entangled and drowned in nets; also, they are intentionally harpooned in the Strait of Magellan and around Tierra del Fuego. The number harpooned, for use as bait in crab traps, may pose a serious threat to their status. A population estimate does not exist.
IUCN Status
Insufficiently known.