Overview

Distribution

Range Description

Previously known primarily from the southern coast of eastern South America, from Uruguay and southern Brazil to Tierra del Fuego, this species is now known from offshore in the southern Hemisphere (Brownell and Clapham 1999). There are records from the Falkland Islands, South Georgia, Kerguelen Islands, Heard Island, Macquarie Island, and the Auckland Islands. Although rarely seen at sea (there are only a few dozen live sightings), this information suggests that the spectacled porpoise’s range may be circumpolar in the sub-Antarctic zone (with water temperatures of at least 1-10°C) (Goodall 2002). The southernmost sighting is from 64°34'S.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

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.

Biogeographic Regions: indian ocean (Native ); atlantic ocean (Native ); pacific ocean (Native )

  • Minasian, S., K. Balcomb, L. Foster. 1984. The World's Whales: The Complete Illustrated Guide. Washington, D.C.: Smithsonian Books.
  • Brownell, R. November 21, 1975. <>. 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..
  • Tinker, S. 1988. Whales of the World. Honolulu, Hawaii: Bess Press Inc..
  • 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.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Morphology

Physical Description

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.

Range mass: 115 (high) kg.

Average mass: 55-80 kg.

Range length: 1.25 to 2.24 m.

Average length: 2 males, 1.8 females m.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

offshore and estuarine
  • UNESCO-IOC Register of Marine Organisms
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Habitat and Ecology

Habitat and Ecology
Spectacled porpoises seem to occur only in cold temperate waters. Although they have been observed or incidentally caught in coastal waters and reported from rivers and channels, their habitat is thought to be primarily oceanic. Where recorded, water temperatures associated with sightings ranged from 5.5°C to 9.5°C (Brownell and Clapham, 1999).

Only four stomachs have been examined; the contents included anchovies and stomatopods (mantis shrimp).

Systems
  • Marine
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

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.

Habitat Regions: temperate ; saltwater or marine

Aquatic Biomes: pelagic ; coastal

  • Nowak, R. 1999. Walker's Mammals of the World. Baltimore and London: Johns Hopkins University Press.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Trophic Strategy

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.

Animal Foods: fish; mollusks; aquatic crustaceans

Primary Diet: carnivore (Piscivore )

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Associations

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.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Predation

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.

Known Predators:

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life History and Behavior

Behavior

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: echolocation

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life Expectancy

Lifespan/Longevity

The lifespan of P. dioptrica is unknown.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

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.

Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); 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)

  • Minasian, S., K. Balcomb, L. Foster. 1984. The World's Whales: The Complete Illustrated Guide. Washington, D.C.: Smithsonian Books.
  • Brownell, R. November 21, 1975. <>. Mammalian Species Special Publication of the American Society of Mammalogists, No. 66: 1-3.
  • Tinker, S. 1988. Whales of the World. Honolulu, Hawaii: Bess Press Inc..
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
DD
Data Deficient

Red List Criteria

Version
3.1

Year Assessed
2008

Assessor/s
Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B.

Reviewer/s
Rojas-Bracho, L. & Smith, B.D. (Cetacean Red List Authority)

Contributor/s

Justification
This is a very poorly known species, and there is a lack of information to make an assessment of its extinction risk.

History
  • 1996
    Data Deficient
  • 1996
    Data Deficient
  • 1994
    Insufficiently Known
    (Groombridge 1994)
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

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

US Migratory Bird Act: no special status

US Federal List: no special status

CITES: appendix ii

IUCN Red List of Threatened Species: data deficient

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Population

Population
There are no estimates of abundance.

Population Trend
Unknown
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Threats

Major Threats
Spectacled porpoises may be taken deliberately for crab bait off southern Chile. The effects of these catches on spectacled porpoise subpopulations are not known (Jefferson et al.1993).

Like all phocoenoids, spectacled porpoises are caught in gillnets. At least 34 animals were killed incidentally between 1975 and 1990 in coastal gill nets set in Tierra del Fuego, and there was a co-occurrence of strandings and fishing activity in southeastern Chile, suggesting additional undocumented mortality from this source. Some mortality of spectacled porpoises was also reported from bottom and mid-water trawls off the coast of Chubut, Argentina (Brownell and Clapham, 1999).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Management

Conservation Actions

Conservation Actions
The species is listed in Appendix II of CITES.

Estimates of abundance are needed as well as information on direct and incidental takes.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

Economic Importance for Humans: Negative

Spectacled porpoises have no recorded adverse affects on humans.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Economic Importance for Humans: Positive

Native people in South America hunt P. dioptrica, but not for commercial uses.

Positive Impacts: food

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Risks

IUCN Red List Category

Data Deficient (DD)
  • IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species.
Creative Commons Attribution 3.0 (CC BY 3.0)

© WoRMS for SMEBD

Source: World Register of Marine Species

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

Spectacled porpoise

The spectacled porpoise (Phocoena dioptrica) is a rarely seen member of the porpoise family. The species is readily distinguished from other porpoises by a characteristic dark ring around the eyes, which gives the animals their name. This ring is commonly surrounded by a farther lighter ring.

Taxonomy[edit]

The spectacled porpoise was first described by Lahille in 1912 from a specimen found on a beach near Buenos Aires. A skull later found in Tierra del Fuego was initially thought to be another species, provisionally named Phocoena dioptrica but the individual was later shown to be a spectacled porpoise and this name remains a synonym. The Latin word dioptrica refers to the double eye rings characterizing the creature.

Physical description[edit]

The spectacled porpoise is a robust creature with a small head and no beak. Spectacled porpoises have distinctive black and white markings - black above and white underneath. They have black eyes with white rings or spectacles, and a white stripe on the upper surface of the tail. They have a large rounded dorsal fin, and no beak. Like all porpoises, they have spade-shaped teeth (as opposed to conical in dolphins). Newborn members of this species are about 80 cm with males growing up to 2.2 metres and females somewhat smaller. The age at which they reach maturity, as well as the porpoise's longevity, is unknown. They can grow up to 60–84 kg (130-185 lbs) in weight as adults.

Diet[edit]

These porpoises feed on squid and fish, yet also on octopus, shrimp, molluscs, and other crustaceans.

Behaviour[edit]

Spectacled porpoises live in groups of 1-25. They are fast, active swimmers, and they normally avoid boats. Little else is known about their behaviour as most of the information has been gleaned from stranded individuals.

Distribution and population[edit]

The spectacled porpoise is believed to be circumpolar in cool sub-Antarctic and low Antarctic waters. Many skeletons have been found on Tierra del Fuego and this area is believed to be a site of relatively high concentration. This species has been seen off Brazil, the Falkland Islands and South Georgia in the Atlantic, off Auckland, Tasmania and south Australia in the South Pacific and Heard Island and Kerguelen in the southern Indian Ocean. Individuals have very rarely been seen in the open sea. The southernmost sighting was in the Drake Passage at 58° S.

The total population is unknown. The IUCN lists it as a data deficient species in the Red List of Threatened Species.

Conservation[edit]

The spectacled porpoise is listed on appendix II[1] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix II[1] as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.

See also[edit]

References[edit]

  1. ^ a b "Appendix II" of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). As amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005 and 2008. Effective: 5th March 2009.
  • Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B. (2008). Phocoena dioptrica. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 24 March 2009. Database entry includes justification for why this species is listed as data deficient
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!