Boto
Encyclopedia
The Amazon river dolphin, alternatively Bufeo, Bufeo Colorado, Boto Cor de Rosa, Boutu, Nay, Tonina, or Pink Dolphin (Inia geoffrensis), is a freshwater river dolphin
endemic to the Orinoco
, Amazon
and Araguaia/Tocantins River
systems of Brazil
, Bolivia
, Peru
, Ecuador
, Colombia
and Venezuela
. The species is one of a handful of oceanic
and river dolphin
s included in a paraphyletic clade
known as the boto
s, and is the largest of the river dolphins. Because they are unfused, the neck vertebrae of the Amazon river dolphin are able to turn 180 degrees. The pink dolphin lives in the freshwater of the Amazon River. This species looks like the grey dolphin, but individuals are bigger, and, instead of a dorsal fin, they have a hump on their back. Their tails are also bigger. The pink dolphin has been listed as endangered by the International Union for Conservation of the Nature due to pollution, overfishing, excessive boat trafficking and habitat loss. The brain
of the river dolphin is 40% larger than a human brain.
The IUCN lists various other names to describe this species, including Amazon Dolphin, Boto Vermelho, Boto Cor-de-Rosa, Bouto, Inia, Pink Dolphin, Wee Quacker, Pink Freshwater Dolphin, Pink Porpoise, Tonina and Encantado.
and Orinoco
. It is particularly abundant in lowland rivers with extensive floodplains. During the annual rainy season these rivers flood large areas of forests and marshes along their banks. The Amazon River Dolphin specializes in hunting in these habitats, taking advantage of its unusually flexible neck and spinal cord to maneuver among the underwater tree trunks, and using its long snout to extract prey fish from hiding places in hollow logs and thickets of submerged vegetation.
When the water levels drop, the dolphins move either into the main river channels or into large lakes in the forest, and take advantage of the concentrated prey in these reduced water bodies.
The young follow their parents closely for a few months, and often two adults are seen swimming with two or more small juveniles.
in 1817.
Rice's 1998 classification lists a single species, Inia geoffrensis, in the genus Inia, with three recognized subspecies. Some older classifications, as well as some recent publications, listed the boliviensis population as a separate species; however, a great majority of the scientific community, including the IUCN, consider the boliviensis population to be a subspecies of Inia geoffrensis.
The three currently recognized subspecies are:
folklore
, at night, an Amazon river dolphin becomes a handsome young man who seduces girls, impregnates them, and then returns to the river in the morning to become a dolphin again. This dolphin shapeshifter
is called an encantado
. It has been suggested that the myth arose partly because dolphin genitalia bear a resemblance to those of humans. Others believe that the myth served (and still serves) as a way of hiding the incestuous relations which are quite common in some small isolated communities alongside the river. In the area, there are tales that it is bad luck to kill a dolphin. Legend also states that if a person makes eye contact with an Amazon river dolphin, he or she will have lifelong nightmares. Local legends also state that the dolphin is the guardian of the Amazonian manatee
, and that, should one wish to find a manatee, one must first make peace with the dolphin.
Associated with these legends is the use of various fetishes such as dried eyeballs and genitalia. These may or may not be accompanied by the intervention of a priest. A recent study has shown that, despite the claim of the seller and the belief of the buyers, none of these fetishes are derived from the boto. They are derived from Sotalia guianensis, are most likely harvested along the coast and the Amazon River
delta, and then are traded up the Amazon River
. In inland cities that are far from the coast, many if not most of the fetishes are derived from domestic animals such as sheep and pigs.
The 1987 Brazilian film Ele, o Boto is a supernatural romance featuring an Amazon river dolphin who has a son by a young woman.
s, crab
s, small turtles, catfish
, piranha
, shrimp
, and other fish.
). It is listed on Appendix II as it has an unfavorable conservation status or would benefit significantly from international co-operation organized by tailored agreements.
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...
endemic to the Orinoco
Orinoco
The Orinoco is one of the longest rivers in South America at . Its drainage basin, sometimes called the Orinoquia, covers , with 76.3% of it in Venezuela and the remainder in Colombia...
, Amazon
Amazon 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 Araguaia/Tocantins River
Tocantins River
The Tocantins is a river in Brazil, the central fluvial artery of the country. In the Tupi language, its name means "toucan's beak" . It runs from south to north for about 2,640 km. It is not really a branch of the Amazon River, although usually so considered, since its waters flow into the...
systems of 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...
, Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
, 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....
, 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...
, 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 Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
. The species is one of a handful of oceanic
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...
and 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 included in a paraphyletic clade
Paraphyly
A group of taxa is said to be paraphyletic if the group consists of all the descendants of a hypothetical closest common ancestor minus one or more monophyletic groups of descendants...
known as the boto
Boto
The Amazon river dolphin, alternatively Bufeo, Bufeo Colorado, Boto Cor de Rosa, Boutu, Nay, Tonina, or Pink Dolphin , is a freshwater river dolphin endemic to the Orinoco, Amazon and Araguaia/Tocantins River systems of Brazil, Bolivia, Peru, Ecuador, Colombia and Venezuela...
s, and is the largest of the river dolphins. Because they are unfused, the neck vertebrae of the Amazon river dolphin are able to turn 180 degrees. The pink dolphin lives in the freshwater of the Amazon River. This species looks like the grey dolphin, but individuals are bigger, and, instead of a dorsal fin, they have a hump on their back. Their tails are also bigger. The pink dolphin has been listed as endangered by the International Union for Conservation of the Nature due to pollution, overfishing, excessive boat trafficking and habitat loss. The brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
of the river dolphin is 40% larger than a human brain.
The IUCN lists various other names to describe this species, including Amazon Dolphin, Boto Vermelho, Boto Cor-de-Rosa, Bouto, Inia, Pink Dolphin, Wee Quacker, Pink Freshwater Dolphin, Pink Porpoise, Tonina and Encantado.
Habitat
The Amazon River Dolphin is found throughout the AmazonAmazon 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 Orinoco
Orinoco
The Orinoco is one of the longest rivers in South America at . Its drainage basin, sometimes called the Orinoquia, covers , with 76.3% of it in Venezuela and the remainder in Colombia...
. It is particularly abundant in lowland rivers with extensive floodplains. During the annual rainy season these rivers flood large areas of forests and marshes along their banks. The Amazon River Dolphin specializes in hunting in these habitats, taking advantage of its unusually flexible neck and spinal cord to maneuver among the underwater tree trunks, and using its long snout to extract prey fish from hiding places in hollow logs and thickets of submerged vegetation.
When the water levels drop, the dolphins move either into the main river channels or into large lakes in the forest, and take advantage of the concentrated prey in these reduced water bodies.
Reproduction
The male reaches sexual maturity at about 7 feet (2 m) and the female at about 5.5 feet (1.7 m). Most calves are born between July and September after a gestation period of 9 to 12 months; they are about 32 inches long at birth (80 cm) and weigh about 15 pounds.The young follow their parents closely for a few months, and often two adults are seen swimming with two or more small juveniles.
Taxonomy
The species was described by Henri Marie Ducrotay de BlainvilleHenri Marie Ducrotay de Blainville
Henri Marie Ducrotay de Blainville was a French zoologist and anatomist.Blainville was born at Arques, near Dieppe. In about 1796 he went to Paris to study painting, but he ultimately devoted himself to natural history, and attracted the attention of Georges Cuvier, for whom he occasionally...
in 1817.
Rice's 1998 classification lists a single species, Inia geoffrensis, in the genus Inia, with three recognized subspecies. Some older classifications, as well as some recent publications, listed the boliviensis population as a separate species; however, a great majority of the scientific community, including the IUCN, consider the boliviensis population to be a subspecies of Inia geoffrensis.
The three currently recognized subspecies are:
- I. g. geoffrensis—Amazon and Araguaia/Tocantins basin population (excluding Madeira RiverMadeira RiverThe Madeira River is a major waterway in South America, approximately 3,250 km miles long The Madeira is the biggest tributary of the Amazon...
drainage area, upstream of the Teotonio Rapids in RondôniaRondôniaRondônia is a state in Brazil, located in the north-western part of the country. To the west is a short border with the state of Acre, to the north is the state of Amazonas, in the east is Mato Grosso, and in the south is Bolivia. Its capital is Porto Velho. The state was named after Candido Rondon...
) - I. g. boliviensisBolivian River DolphinThe Bolivian river dolphin is a subspecies of the Amazon river dolphin. Although older publications as well as some recent publications consider the boliviensis population as distinct species from Inia geoffrensis, the great majority of the scientific community including the IUCN consider...
—Amazon basin (Bolivian sub-basin) population in the Madeira drainage area in BoliviaBoliviaBolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
upstream of the Teotonio Rapids - I. g. humboldtiana—Orinoco basin population
Legend
In traditional 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...
folklore
Folklore
Folklore consists of legends, music, oral history, proverbs, jokes, popular beliefs, fairy tales and customs that are the traditions of a culture, subculture, or group. It is also the set of practices through which those expressive genres are shared. The study of folklore is sometimes called...
, at night, an Amazon river dolphin becomes a handsome young man who seduces girls, impregnates them, and then returns to the river in the morning to become a dolphin again. This dolphin shapeshifter
Shapeshifting
Shapeshifting is a common theme in mythology, folklore, and fairy tales. It is also found in epic poems, science fiction literature, fantasy literature, children's literature, Shakespearean comedy, ballet, film, television, comics, and video games...
is called an encantado
Encantado
Encantado is a word in Portuguese roughly translating as "enchanted one", and is also a commonly used greeting in Spanish meaning "enchanted", as in "enchanted to meet you". The Brazilian term is used for creatures who come from a paradisiacal underwater realm called the Encante...
. It has been suggested that the myth arose partly because dolphin genitalia bear a resemblance to those of humans. Others believe that the myth served (and still serves) as a way of hiding the incestuous relations which are quite common in some small isolated communities alongside the river. In the area, there are tales that it is bad luck to kill a dolphin. Legend also states that if a person makes eye contact with an Amazon river dolphin, he or she will have lifelong nightmares. Local legends also state that the dolphin is the guardian of the Amazonian manatee
Amazonian Manatee
The Amazonian Manatee is a species of manatee that lives in the freshwater habitats of the Amazon basin. They are found in Brazil, Peru, Colombia, Ecuador, Guyana and Venezuela. Amazonian manatees are aquatic animals of the Sirenia order and are also known as "seacows". Their colour is grey but...
, and that, should one wish to find a manatee, one must first make peace with the dolphin.
Associated with these legends is the use of various fetishes such as dried eyeballs and genitalia. These may or may not be accompanied by the intervention of a priest. A recent study has shown that, despite the claim of the seller and the belief of the buyers, none of these fetishes are derived from the boto. They are derived from Sotalia guianensis, are most likely harvested along the coast and the Amazon River
Amazon 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...
delta, and then are traded up the Amazon River
Amazon 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...
. In inland cities that are far from the coast, many if not most of the fetishes are derived from domestic animals such as sheep and pigs.
Food and diet
The Amazon river dolphin has a long beak which contains 24 to 34 conical and molar-type teeth on each side of the jaws for catching prey and eats crustaceanCrustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, crab
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
s, small turtles, catfish
Catfish
Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
, piranha
Piranha
A piranha or piraña is a member of family Characidae in order Characiformes, an omnivorous freshwater fish that inhabits South American rivers. In Venezuela, they are called caribes...
, shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
, and other fish.
Size
Although not a large cetacean in general terms, this dolphin is the largest cetacean to spend most of its life in freshwater and can grow larger than a human. Body length can range from 1.53 to 2.4 m (5 to 7.9 ft), depending on subspecies. Females are typically larger than males. The largest female Amazon river dolphins can range up to 2.5 m (8.2 ft) in length and weigh 98.5 kg (217.2 lb). The largest male dolphins can range up to 2 m (6.6 ft) in length and weigh 94 kg (207.2 lb).Conservation
The Amazon River dolphin is listed on appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMSBonn 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 unfavorable conservation status or would benefit significantly from international co-operation organized by tailored agreements.
External links
- Indus River dolphins
- Associação Amigos do Peixe-boi—A non-profit organization based in Manaus, Brazil, focusing on all aspects of conservation of Amazonian aquatic mammals including the Amazon river dolphin (Inia geoffrensis).
- Omacha Foundation—A non-government and non-profit organization created to study, research and protect river dolphins and other fauna and aquatic ecosystems in Colombia. Winner of the 2007 Whitley Awards (UK).
- Projeto Boto—A non-profit research project that is increasing knowledge, understanding and the conservation prospects of the Amazon's two endemic dolphins—the Amazon river dolphin (Inia geoffrensis) and the tucuxi (Sotalia fluviatilis).
- River Dolphin Research Program—Amazon innovative research project totally devoted to the study of the ecology and conservation of river dolphins in the Amazon basin, based in the Federal University of Western Pará (UFOPA). The scope of this research project focuses on ecological studies, as well as the impact that human activities have on their survival.
- Convention on Migratory Species page on the Amazon Dolphin
- The Nature Conservancy works to protect habitat for the Amazon River Dolphin
- Animal Info page on the Amazon River Dolphin
- Virtual Explorers
- June 2009 National Geographic story on Amazon River Dolphin
- World Wide Fund for Nature (WWF) species profile for River Dolphins
- Amazon River Dolphins Being Slaughtered for Bait
- Convention on Migratory Species page on the Amazon River dolphin