Tucuxi
Encyclopedia
The Tucuxi alternately bufeo gris or bufeo negro (both in Peru
) is a dolphin
found in the rivers of the Amazon Basin
. The word "tucuxi" is derived from the Tupi language word tuchuchi-ana and has now been adopted as the species' common name. Despite being found in geographic locations similar to those of 'true' river dolphin
s such as the Boto, the Tucuxi is not closely related to them genetically. Instead it is classed in the oceanic dolphin
family (Delphinidae). Physically the species, particularly the marine variety, resembles the Bottlenose Dolphin
. However, this species is sufficiently different from the Bottlenose Dolphin that it is given its own genus
, Sotalia. Animals formerly called the Tucuxi occurring in coastal and estuarine environments have recently been recognized as a distinct species Costero
(Sotalia guianensis).This is also known as the pink dolphin.
& Deville
in 1853, and the Costero Sotalia guianensis by Pierre-Joseph van Bénéden
in 1864. These two species were subsequently synonymized, with the two species being treated as subspecies of marine and freshwater varieties. The first to reassert differences between these two species was a three-dimensional morphometric study of Monteiro-Filho and colleagues. Subsequently a molecular analysis by Cunha and colleagues unambiguously demonstrated that Sotalia guianensis was genetically differentiated from Sotalia fluviatilis. This finding was reiterated by Caballero and colleagues with a larger number of genes. The existence of two species has been generally accepted by the scientific community, however, the IUCN still treats both species as a single species Sotalia fluviatilis.
and many of its tributaries, and is found in Brazil
, Peru
, south-east Colombia
, and eastern Ecuador
. Numerous individuals have been seen in the Orinoco River further north, though it is not clear whether these are Tucuxi or Costero
.
Tucuxis have been observed to feed with other river dolphins. They feed on a wide variety of fish. Studies of growth layers suggest that the species can live up to 35 years.
poisoning
of water
due to gold
mining, is a particular concern for this species.
Tucuxis are observed not to maintain good health and attitude in captive environments. A few Tucuxis remained in captivity in European aquaria, but the last one (Paco) died in 2009 in the Zoo of Münster, Germany.
The Tucuxi is listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS
). It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
) is a dolphin
Dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...
found in the rivers of the Amazon Basin
Amazon Basin
The Amazon Basin is the part of South America drained by the Amazon River and its tributaries that drains an area of about , or roughly 40 percent of South America. The basin is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela...
. The word "tucuxi" is derived from the Tupi language word tuchuchi-ana and has now been adopted as the species' common name. Despite being found in geographic locations similar to those of 'true' river dolphin
River dolphin
River dolphins are the four living species of dolphin that reside in freshwater rivers and estuaries. River dolphins inhabit areas of Asia and South America. They are classed in the Platanistoidea superfamily of cetaceans. Three species live in fresh water rivers. The fourth species, the La Plata...
s such as the Boto, the Tucuxi is not closely related to them genetically. Instead it is classed in the oceanic dolphin
Oceanic dolphin
Oceanic dolphins are the members of the Delphinidae family of cetaceans. These marine mammals are related to whales and porpoises. They are found worldwide, mostly in the shallower seas of the continental shelves...
family (Delphinidae). Physically the species, particularly the marine variety, resembles the Bottlenose Dolphin
Bottlenose Dolphin
Bottlenose dolphins, the genus Tursiops, are the most common and well-known members of the family Delphinidae, the family of oceanic dolphins. Recent molecular studies show the genus contains two species, the common bottlenose dolphin and the Indo-Pacific bottlenose dolphin , instead of one...
. However, this species is sufficiently different from the Bottlenose Dolphin that it is given its own genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, Sotalia. Animals formerly called the Tucuxi occurring in coastal and estuarine environments have recently been recognized as a distinct species Costero
Costero
The Costero is found in the coastal waters to the north and east of South America. The common name "costero" has been suggested by Caballero and colleagues due to the species' affinity for coastal habitats. The Costero is a member of the oceanic dolphin family . Physically it resembles the...
(Sotalia guianensis).This is also known as the pink dolphin.
Description
The Tucuxi is frequently described (see references below) as looking similar to the Bottlenose Dolphin. However it is typically smaller at around 150 cm. The dolphin is coloured light to bluish grey on its back and sides. The ventral region is much lighter, often pinkish. The dorsal fluke is typically slightly hooked. The beak is well-defined and of moderate length. There are 26 to 36 pairs of teeth in the upper and lower jaws.Taxonomy
The Tucuxi Sotalia fluviatilis was described by GervaisPaul Gervais
For the Canadian parliamentarian see Paul Mullins GervaisPaul Gervais full name François Louis Paul Gervaise was a French palaeontologist and entomologist.-Biography:...
& Deville
Emile Deville
Emile Deville was a French physician , naturalist and taxidermistEmile Deville, already an employee of Muséum national d'histoire naturelle joined the 1843 expedition of Francis de Laporte de Castelnau to South America with the doctor and botanist Hugh Algernon Weddell...
in 1853, and the Costero Sotalia guianensis by Pierre-Joseph van Bénéden
Pierre-Joseph van Beneden
Pierre-Joseph van Beneden was a Belgian zoologist and paleontologist.Born in Mechelen, Belgium, he studied medicine at the University of Louvain, and studied zoology in Paris under Georges Cuvier...
in 1864. These two species were subsequently synonymized, with the two species being treated as subspecies of marine and freshwater varieties. The first to reassert differences between these two species was a three-dimensional morphometric study of Monteiro-Filho and colleagues. Subsequently a molecular analysis by Cunha and colleagues unambiguously demonstrated that Sotalia guianensis was genetically differentiated from Sotalia fluviatilis. This finding was reiterated by Caballero and colleagues with a larger number of genes. The existence of two species has been generally accepted by the scientific community, however, the IUCN still treats both species as a single species Sotalia fluviatilis.
Distribution
The Tucuxi exists along much the length of the Amazon RiverAmazon River
The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined...
and many of its tributaries, and is found in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, south-east Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, and eastern Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
. Numerous individuals have been seen in the Orinoco River further north, though it is not clear whether these are Tucuxi or Costero
Costero
The Costero is found in the coastal waters to the north and east of South America. The common name "costero" has been suggested by Caballero and colleagues due to the species' affinity for coastal habitats. The Costero is a member of the oceanic dolphin family . Physically it resembles the...
.
Behavior
The Tucuxi exist in small groups of about 10-15 individuals and swim in tight-knit groups, suggesting a highly developed social structure. Tucuxis are quite active and may jump clear of the water (a behavior known as breaching), somersault, spy-hop or tail-splash. They are unlikely however to approach boats.Tucuxis have been observed to feed with other river dolphins. They feed on a wide variety of fish. Studies of growth layers suggest that the species can live up to 35 years.
Conservation
The Tucuxi is endemic to the regions described above and, although no precise estimates of population are available, it is common. A significant human problem are fishing nets. Deliberate hunting in the Amazon Basin for food has also been reported. Pollution, in particular mercuryMercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
poisoning
Mercury poisoning
Mercury poisoning is a disease caused by exposure to mercury or its compounds. Mercury is a heavy metal occurring in several forms, all of which can produce toxic effects in high enough doses...
of water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
due to gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...
mining, is a particular concern for this species.
Tucuxis are observed not to maintain good health and attitude in captive environments. A few Tucuxis remained in captivity in European aquaria, but the last one (Paco) died in 2009 in the Zoo of Münster, Germany.
The Tucuxi is listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS
Bonn Convention
The Convention on the Conservation of Migratory Species of Wild Animals aims to conserve terrestrial, marine and avian migratory species throughout their range...
). It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.
External links
- Projeto Boto - a non-profit research project that is increasing knowledge, understanding and the conservation prospects of the Amazon's two endemic dolphins - the boto (Inia geoffrensis) and the tucuxi (Sotalia fluviatilis)
- Whale and Dolphin Conservation Society (WDCS)
- World Wide Fund for Nature (WWF) - species profile for River Dolphins
- Convention on Migratory Species page on the Tucuxi