Phocoena dioptrica
spectacled porpoise

Spectacled porpoises are rarely seen and are found only in the oceans of the southern hemisphere. Usually they are found near the southern east coast of South America (from Uruguay and Argentina to Cape Horn) and also near the Falkland Islands and South Georgia. Phocoena dioptrica have been seen near New Zealand, Macquarie Island and the Auckland Islands in the Pacific Ocean, and Heard Island and the Kerguelen Islands in the Indian Ocean. (Bannister, et al., September 1996; Brownell, November 21, 1975; Coffey, 1977; Minasian, et al., 1984; Tinker, 1988)

Spectacled porpoises prefer cold ocean waters of the southern hemisphere. They normally live near offshore islands but are sometimes found in the open ocean. They seem to prefer the subantarctic area where there are cold currents like the Falkland Current. (Bannister, et al., September 1996; Nowak, 1999)

Size of this species can vary from about 1.25 meters (females) to 2.24 meters (males). The average weight of P. dioptrica varies from 55 to 80 kilograms; the largest individual found was 115 kilograms. The dorsal side is a blue-black color and the ventral side is pure white. There is a sharp line that divides the dorsal black color from the ventral white color. There is a gray line that goes from the corners of the mouth to the leading edge of the pectoral flippers, which are white. The lips are also black and the eyes are surrounded by black circles that look like glasses. The tail fluke is dark on the top side and white on the bottom. Shape also distinguishes this species. The dorsal fin is big and triangular and the pectoral fins are small and rounded when compared to other Phocoena species. The teeth in the upper jaw number between 18 and 23 and the teeth in the lower jaw number between 16 and 19 on each side. The teeth have spade-shaped crowns, which is a distinguishing characteristic of porpoises when compared to dolphins, which have cone-shaped crowns. There also are some skull features that distinguish P. dioptrica from P. phocoena: the top of the rostrum of P. dioptrica is flatter, and from the side, the premaxillary bones of P. dioptrica are less visible. (Bannister, et al., September 1996; Brownell, November 21, 1975; Coffey, 1977; Minasian, et al., 1984; Nowak, 1999; Tinker, 1988)

No information is available on the mating systems of this species.

All mammals reproduce sexually via internal fertilization and all eutherian mammals give birth to live young. However, very little else is known about the reproductive behaviors of P. dioptrica. One near-term fetus was recorded in July 1912 and another was taken in August of the same year. The first fetus was a female and was 484 millimeters long. No information was recorded on the second fetus. The young are most likely born in early spring, but no information is recorded. (Brownell, November 21, 1975; Minasian, et al., 1984; Tinker, 1988)

A feature common to all eutherian mammals is that females nuture their young inside their bodies until birth, and afterwards provide them with milk. However, no specific information on parental investment is available for P. dioptrica.

The lifespan of P. dioptrica is unknown.

This species does not travel in large groups. They are probably solitary animals, but they have been seen in groups of two or three individuals. They are probably not migratory. (Bannister, et al., September 1996; Tinker, 1988)

Nothing has been recorded about the communication or perception of P. dioptrica, but they probably use echolocation as do other porpoises.

The food preferences of spectacled porpoises are not well known. They are most likely similar to other porpoises, which eat fish, squid, and crustaceans. (Bannister, et al., September 1996)

Nothing is recorded about predation of P. dioptrica. It is possible that killer whales are their only natural predators. They also are hunted by humans. (Bannister, et al., September 1996; Brownell, November 21, 1975; Coffey, 1977)

Porpoises are predators of fish and aquatic invertebrates, and they sometimes provide a food source to killer whales. Nothing specific is known about the role of P. dioptrica in the ecosystem.

Native people in South America hunt P. dioptrica, but not for commercial uses. (Coffey, 1977)

Spectacled porpoises have no recorded adverse affects on humans. (Tinker, 1988)

Not enough information is known about this species in order to list it as endangered.

Spectacled porpoises were previously known as Australophocaena dioptrica and Phocoena storni. Their Spanish common name is Marsopa de Anteojos. (Brownell, November 21, 1975; Tinker, 1988)