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Home -> Kingdom Animalia -> Phylum Chordata -> Subphylum Vertebrata -> Class Mammalia -> Order Cetacea -> Suborder Odontoceti -> Family Phocoenidae -> Species Phocoena dioptrica

Phocoena dioptrica
spectacled porpoise



2009/11/29 04:24:16.459 US/Eastern

By Jennifer Nixon

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Cetacea
Suborder: Odontoceti
Family: Phocoenidae
Genus: Phocoena
Species: Phocoena dioptrica

Geographic Range

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, Kemper, and Warneke, September 1996; Brownell and November 21, 1975; Coffey, 1977; Minasian, Balcomb, and Foster, 1984; Tinker, 1988)

Biogeographic Regions:
indian ocean (native ); atlantic ocean (native ); pacific ocean (native ).

Habitat

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, Kemper, and Warneke, September 1996; Nowak, 1999)

These animals are found in the following types of habitat:
temperate ; saltwater or marine .

Aquatic Biomes:
pelagic ; coastal .

Physical Description

Mass
115 kg (high); avg. 67.50 kg
(253 lbs; avg. 148.5 lbs)


Length
1.25 to 2.24 m; avg. 2 males, 1.8 females m
(4.1 to 7.35 ft; avg. ft)


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, Kemper, and Warneke, September 1996; Brownell and November 21, 1975; Coffey, 1977; Minasian, Balcomb, and Foster, 1984; Nowak, 1999; Tinker, 1988)

Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .

Reproduction

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 and November 21, 1975; Minasian, Balcomb, and Foster, 1984; Tinker, 1988)

Key reproductive features:
iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous .

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.

Parental investment:
pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female).

Lifespan/Longevity

The lifespan of P. dioptrica is unknown.

Behavior

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, Kemper, and Warneke, September 1996; Tinker, 1988)

Key behaviors:
natatorial ; motile ; solitary ; social .

Communication and Perception

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

Perception channels:
tactile ; echolocation ; chemical .

Food Habits

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, Kemper, and Warneke, September 1996)

Primary Diet:
carnivore (piscivore ).

Animal Foods:
fish; mollusks; aquatic crustaceans.

Predation

Known predators

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, Kemper, and Warneke, September 1996; Brownell and November 21, 1975; Coffey, 1977)

Ecosystem Roles

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.

Economic Importance for Humans: Negative

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

Economic Importance for Humans: Positive

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

Ways that people benefit from these animals:
food .

Conservation Status

IUCN Red List: [link]:
Data Deficient.

US Migratory Bird Act: [link]:
No special status.

US Federal List: [link]:
No special status.

CITES: [link]:
Appendix II.

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

Other Comments

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

For More Information

Find Phocoena dioptrica information at

Contributors

Allison Poor (editor), University of Michigan.

Jennifer Nixon (author), University of Northern Iowa.
Jim Demastes (editor), University of Northern Iowa.

References

Bannister, J., C. Kemper, R. Warneke. September 1996. "The Action Plan for Australian Cetaceans" (On-line). Accessed November 28, 2001 at http://www.deh.gov.au/coasts/species/cetaceans/actionplan/whaleap5a.html.

Brownell, R. November 21, 1975. <<Phocoena dioptrica>>. Mammalian Species Special Publication of the American Society of Mammalogists, No. 66: 1-3.

Coffey, D. 1977. Dolphins, Whales and Porpoises: An Encyclopedia of Sea Mammals. New York: Macmillan Publishing Co., Inc..

Minasian, S., K. Balcomb, L. Foster. 1984. The World's Whales: The Complete Illustrated Guide. Washington, D.C.: Smithsonian Books.

Nowak, R. 1999. Walker's Mammals of the World. Baltimore and London: Johns Hopkins University Press.

Tinker, S. 1988. Whales of the World. Honolulu, Hawaii: Bess Press Inc..

2009/11/29 04:24:18.260 US/Eastern

To cite this page: Nixon, J. 2003. "Phocoena dioptrica" (On-line), Animal Diversity Web. Accessed December 05, 2009 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Phocoena_dioptrica.html.

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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