iLa Plata Dolphin
Conservation status
Data deficient (DD)
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Subclass: Eutheria Order: Cetacea Suborder: Odontoceti Superfamily: Platanistoidea Family: Pontoporiidae Gray, 1870 Genus: Pontoporia Species: P. blainvillei
Binomial name
Pontoporia blainvillei Gervais & d'Orbigny, 1844
La Plata Dolphin range

The La Plata Dolphin (Pontoporia blainvillei) is found in coastal Atlantic waters of southeastern South America. Taxonomically it is a member of the river dolphin group and the only one that actually lives in the ocean and saltwater estuaries, rather than inhabiting exclusively freshwater systems. The conservation status of a species is an indicator of the likelihood of that species continuing to survive. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Subregnum Parazoa Porifera Subregnum Eumetazoa Placozoa Orthonectida Rhombozoa Radiata (unranked) Ctenophora Cnidaria Bilateria (unranked) Acoelomorpha Myxozoa Superphylum Deuterostomia Chordata Hemichordata Echinodermata Chaetognatha Xenoturbellida Superphylum Ecdysozoa Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Onychophora Tardigrada Arthropoda Superphylum Platyzoa Platyhelminthes Gastrotricha Rotifera Acanthocephala Gnathostomulida Micrognathozoa Cycliophora Superphylum Lophotrochozoa Sipuncula Nemertea Phoronida Bryozoa Entoprocta... {{{subdivision_ranks}}} See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Orders Multituberculata (extinct) Palaeoryctoides (extinct) Triconodonta (extinct) Subclass Australosphenida Ausktribosphenida Monotremata Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Arctostylopida (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Cingulata Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Leptictida (extinct) Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata... Eutheria is a taxon (specifically, an infraclass) nearly synonymous with Placentalia, containing the placental mammals and the nearest ancestors of placental mammals (which are known only from the fossil record). ... Suborders Mysticeti Odontoceti Archaeoceti (extinct) (see text for families) The order Cetacea includes whales, dolphins and porpoises. ... Families See text The toothed whales (systematic name Odontoceti) form a suborder of the cetaceans. ... Families See text River dolphins are four species of dolphin which reside in freshwater rivers and estuarys. ... John Edward Gray. ... In biology, binomial nomenclature is the formal method of naming species. ... Image File history File links Cetacea_range_map_La_Plata_River_Dolphin. ... South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... Families See text River dolphins are four species of dolphin which reside in freshwater rivers and estuarys. ... Estuaries and coastal waters are among the most productive ecosystems on Earth, providing ecological, economic, cultural, and aesthetic benefits. ...

Taxonomy

The La Plata Dolphin is the only species in its genus. It was first described by Paul Gervais and Alcide d'Orbigny in 1844 (the species epithet blainvillei commemorates the French zoologist Henri Marie Ducrotay de Blainville). The La Plata Dolphin is also widely known as the Franciscana - the Argentine and Uruguayan name that has been adopted internationally. Other common names are the Toninha (the Brazilian name) and Cachimbo. Paul Gervais (September 26, 1816 - February 10, 1879) was a French palaeontologist. ... Alcide Charles Victor Marie Dessalines dOrbigny (September 6, 1802 - June 30, 1857) was a great French naturalist. ... Henri Marie Ducrotay de Blainville Henri Marie Ducrotay de Blainville (September 12, 1777 - May 1, 1850) was a French zoologist and anatomist. ...

Physical description

The La Plata Dolphin has the longest beak (as a proportion of body size) of any cetacean — as much as 15% in older adults. Males grow to 1.6 m (5 ft, 3 in) and females to 1.8 m (5 ft, 10 in). The body is a greyish brown colour, with a lighter underside. The flippers are also very large in comparison with body size and are very broad, but narrow on joining the body and so are almost triangular in shape. The trailing edges are serrated. The crescent-shaped blowhole lies just in front of a crease in the neck, giving the impression that dolphin forever has its head cricked upwards. The dorsal fin has a long base and a rounded tip. Dorsal Fin of the Orca A dorsal fin is a fin located on the backs of fishes, whales, dolphins and porpoises. ...

The La Plata Dolphin weighs up to 50 kg (110 lb) and lives for up to 20 years. The gestation period is around 10-11 months and juveniles take just a few years to mature. Females may be giving birth by the age of five.

The animal is very inconspicuous - it moves very smoothly and slowly—and can be difficult to spot unless estuary conditions are very calm. They will commonly swim alone or in small groups. Exceptionally groups as large as 15 have been seen. La Plata Dolphins are bottom feeders and gut inspections have revealed they eat at least 24 different species of fish, depending on which species are most common. They will also take octopus, squid and shrimp. They are themselves hunted by orca and several species of shark. Families 11 in two suborders, see text. ... SQUIDs, or Superconducting Quantum Interference Devices, are used to measure extremely small magnetic fields; they are currently the most sensitive such devices (magnetometers) known, with noise levels as low as 3 fT·Hz−½. While a typical fridge magnet is ~0. ... Superfamilies Alpheoidea Atyoidea Bresilioidea Campylonotoidea Crangonoidea Galatheacaridoidea Nematocarcinoidea Oplophoroidea Palaemonoidea Pandaloidea Pasiphaeoidea Procaridoidea Processoidea Psalidopodoidea Stylodactyloidea True shrimp are small, swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. ... Binomial name Orcinus orca Linnaeus, 1758 Orca range (in blue) The Orca or Killer Whale (Orcinus orca) is the largest species of the oceanic dolphin family (Delphinidae). ... Orders Carcharhiniformes Heterodontiformes Hexanchiformes Lamniformes Orectolobiformes Pristiophoriformes Squaliformes Squatiniformes Sharks (superorder Selachimorpha) are fish with a full cartilaginous skeleton[1] and a streamlined body. ...

Range and habitat

The La Plata Dolphin is found in the coastal Atlantic waters of southeastern South America, including the Río de la Plata estuary. Its distribution ranges from the Tropic of Capricorn near Ubatuba, Brazil, south to Península Valdés, Argentina. It is the only member of the river dolphin group that actually lives in the ocean and saltwater estuaries, rather than freshwater. Although some members of the species do spend portions of their live outside of river systems, there are many individuals who live their entire lives within rivers, never venturing into the ocean proper. South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... Río de la Plata in relation to Uruguay and Argentina A satellite view of the estuary The Río de la Plata (from Spanish: Silver River), also known by the English name River Plate, as in the Battle of the River Plate, or sometimes [La] Plata River, is the... Estuaries and coastal waters are among the most productive ecosystems on Earth, providing ecological, economic, cultural, and aesthetic benefits. ... World map showing the Tropic of Capricorn The Tropic of Capricorn or Southern tropic is one of the five major circles of latitude that mark maps of the Earth. ... Ubatuba is a Brazilian city, located on the southeast coast of this country, in the state of São Paulo. ... Peninsula Valdés, photo taken during shuttle mission STS-68 Peninsula Valdés is a peninsula along the Atlantic coast in Chubut Province, Argentina. ... Estuaries and coastal waters are among the most productive ecosystems on Earth, providing ecological, economic, cultural, and aesthetic benefits. ...

Conservation

The La Plata Dolphin is listed as "data deficient" in the IUCN Red List of Threatened Species. However this listing masks widespread concern amongst conservationists that the species will not be able to absorb the number of accidental killings in gillnets that occur each year and maintain a steady population. This species is also threatened by coastal bottom trawl fisheries. In the 1970s most documented killings were off the Uruguayan coast but more recent studies suggest that nets off the southern Brazilian and Argentinian coasts are now the most harmful. Scientists from all three countries have voiced their concerns, and asked for international assistance in highlighting the plight of the dolphin (see Reeves et al, pg. 53). The total population and population change per year is unknown. The World Conservation Union or International Union for Conservation of Nature and Natural Resources (IUCN) is an international organization dedicated to natural resource conservation. ... The IUCN Red List of Threatened Species (also known as the IUCN Red List and Red Data List), created in 1963, is the worlds most comprehensive inventory of the global conservation status of plant and animal species. ... A gillnet is a type of fishing net, a type of which is the driftnet (which is a drifting gillnet - i. ...

References

• Cetacean Specialist Group (1996). Pontoporia blainvillei. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 12 May 2006. Database entry includes a lengthy justification of why this species is listed as data deficient

The IUCN Red List of Threatened Species (also known as the IUCN Red List and Red Data List), created in 1963, is the worlds most comprehensive inventory of the global conservation status of plant and animal species. ... The World Conservation Union or International Union for Conservation of Nature and Natural Resources (IUCN) is an international organization dedicated to natural resource conservation. ...

External links

• ARKive - images and movies of the Franciscana (Pontoporia blainvillei)
• Dolphins, Whales and Porpoises: 2002-2010 Conservation Action Plan for the World's Cetaceans, Reeves, Smith, Crespo and Notarbartolo di Sciara. Available online at [1].
• Convention on Migratory Species page on the La Plata Dolphin
• Cetacea.org page on the La Plata Dolphin