by zteve t evans

Created on: December 13, 2010   Last Updated: December 14, 2010

Burmeister’s porpoise (Phocoena spinipinnis) are found along the Pacific and Atlantic coastline of South America in shallow coast waters, estuaries and fjords. Along the Pacific coast its range stretches from Cape Horn in the south northwards to Bahia de Paita, Peru.  On the Atlantic coast it is found from Cape Horn northwards up to Sana Catarine, Brazil.

This species gets its name from Herman Burmeister who first described it in 1865.  It is also known as the chancho marino (sea pig), and the marsopa espinosa (thorny porpoise).  It is also called the Black porpoise as it turns black soon after its death as is often seen when it falls victim to fishing nets. 

They are shy and reclusive animals avoiding human contact and will speed away from any approaching boat.   Their dark coloring helps to keep them inconspicuous in the water.  Their swimming style is much less energetic and eye-catching than that of other cetaceans. They tend to surface and break the water much more cautiously and with dives commonly lasting 1-3 minutes they can be quite hard to spot. Consequently, they are difficult to observe and very little is known about their habits and lifestyle.

Physical characteristics

Burmeister’s porpoise can grow up 4.6 feet (1.4 m) and 6 feet (1.8 m) in length and can weigh between 88 pounds (40 kg) and 154 pounds (70 kg). Their bodies are small, though thickset and their backs are mostly darkish grey, or black, turning to a lighter grey underneath.

Its most distinguishing physical feature is its dorsal fin which is set about two thirds of the way down its back towards its tail. The fin is arced back towards the tail and has a series of bumps called tubercles along the front edge.

It has no beak, and its head is a conical shape though the forehead is flattened and has dark patches around the eyes.  On it sides running from its chin to its flippers, is a stripe of dark grey.

Diet

The diet consists mostly of fish such as anchovy and hake and it supplements its diet with squid, and crustaceans.  Those living off the coasts of Chile are known to eat molluscs which have been found in their stomachs.

Breeding

Not much is known about their breeding habits but they are thought to have a gestation period of 11-12 months and give birth every 1-2 years.

Population

There is very little reliable evidence on actual population numbers though they are thought to be more numerous in the waters of the Beagle Channel and Magellan Straits in the region of Tierra del Fuego.  Sightings are rare though they are usually seen swimming alone, or in pairs and occasionally in groups of eight or higher. 

Conservation status

There is very little evidence or scientific data about them and their status is uncertain. Consequently, the International Union for Conservation of Nature have placed them as Data Deficient on their Red List of Threatened Species.

Though protected by law in 1994, their biggest danger is from getting caught in fishing nets and drowning.  Numbers of such incidents are thought to have decreased since the law came in, but they are thought to be harpooned for human food and shark bait. Water pollution from human activity such as chemical disposal and oils spills are also a hazard.

References

http://animals.jrank.org/pages/3143/Porpoises-Phocoe nidae-BURMEISTER-S-PORPOISE-Phocoena-spinipinnis-SPE CIES-ACCOUNTS.html

http://marinebio.org/species.asp?id=439

http://en.wikipedia.org/wiki/Burmeister%27s_porpoise

International Union for Conservation of Nature, http://www.iucnredlist.org/apps/redlist/details/1702 9/0

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