Amazon river dolphin: Difference between revisions
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'''''Inia geoffrensis''''', commonly known as the '''Amazon river dolphin''', is a freshwater [[river dolphin]] endemic to the [[Orinoco]], [[Amazon River|Amazon]] and [[Araguaia]]/[[Tocantins River]] systems of [[Brazil]], [[Peru]], [[Ecuador]], [[Colombia]] and [[Venezuela]]. It is listed as [[Endangered species|Endangered]] by the [[IUCN]] due to pollution, overfishing, excessive boat traffic and habitat loss. |
'''''Inia geoffrensis''''', commonly known as the '''Amazon river dolphin''', is a freshwater [[river dolphin]] endemic to the [[Orinoco]], [[Amazon River|Amazon]] and [[Araguaia]]/[[Tocantins River]] systems of [[Brazil]], [[Peru]], [[Ecuador]], [[Colombia]] and [[Venezuela]]. It is listed as [[Endangered species|Endangered]] by the [[IUCN]] due to pollution, overfishing, excessive boat traffic and habitat loss. |
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Other common names of the species include ''boto'', ''lo lo annaaaa'', ''boto cor-de-rosa'', ''bouto'', and pink dolphin.<ref name="iucn">{{cite book |
Other common names of the species include ''boto'', ''lo lo annaaaa'', ''boto cor-de-rosa'', ''bouto'', and pink dolphin.<ref name="iucn">{{cite book |author=R.R. Reeves, T.A. Jefferson, L. Karczmarski, K. Laidre, G. O'Corry-Crowe, L. Rojas-Bracho, E.R. Secchi, E. Slooten, B.D. Smith, J.Y. Wang, & K. Zhou|title =IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. |chapter=''Inia geoffrensis''|publisher =International Union for Conservation of Nature and Natural Resources|year =2011|url =http://www.iucnredlist.org/apps/redlist/details/10831/0}}</ref> |
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|author=R.R. Reeves, T.A. Jefferson, L. Karczmarski, K. Laidre, G. O'Corry-Crowe, L. Rojas-Bracho, E.R. Secchi, E. Slooten, B.D. Smith, J.Y. Wang, & K. Zhou|title =IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. |chapter=''Inia geoffrensis''|publisher =International Union for Conservation of Nature and Natural Resources|year =2011|url =http://www.iucnredlist.org/apps/redlist/details/10831/0}}</ref><ref>{{cite web | url = http://www.bbc.co.uk/nature/wildfacts/factfiles/62.shtml | title = Wildfacts: Boto | publisher = [[BBC]] | accessdate = December 6, 2011}}</ref> |
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==Description== |
==Description== |
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==Taxonomy== |
==Taxonomy== |
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The species was described by [[Henri Marie Ducrotay de Blainville]] in 1817. Rice's 1998 classification<ref name=Rice>{{cite book | author = Rice, D. W. | year = 1998 | title = Marine mammals of the world: systematics and distribution | publisher = Society of Marine Mammalogy Special Publication Number 4 | pages = 231}}</ref> lists a single species, ''Inia geoffrensis'' in the genus ''Inia'', with three recognized subspecies. Some older classifications, as well as some recent publications,<ref name=Martinez-Aguero>{{cite journal | author = Martínez-Agüero, M., S. Flores-Ramírez, and M. Ruiz-García | year = 2006 | title = First report of major histocompatibility complex class II loci from the Amazon pink river dolphin (genus ''Inia'') | journal = Genetics and Molecular Research| volume = 5 | pages = 421–431 | url = http://www.funpecrp.com.br/gmr/year2006/vol3-5/pdf/gmr0202.pdf | pmid = 17117356 | issue = 3}}</ref> listed the ''boliviensis'' population as a separate species. In 2012 the [[Society for Marine Mammalogy]]<ref name="MMS">"[http://www.marinemammalscience.org/index.php?option=com_content&view=article&id=645&Itemid=340]" Committee on Taxonomy. 2012. List of marine mammal species and subspecies. Society for Marine Mammalogy, www.marinemammalscience.org, consulted on May, 6 2012. </ref> began considering the Bolivian (''Inia geoffrensis boliviensis'') and Amazonian (''Inia geoffrensis geoffrensis'') subspecies as full species; however, much of the scientific community, including the [[IUCN]],<ref name="iucn"/> consider the ''boliviensis'' population to be a subspecies of ''Inia geoffrensis''. The genus ''Inia'' separated from its sister taxon during the Miocene epoch.<ref name=Hamilton>{{cite journal | author = Hamilton, H., S. Caballero, A. G. Collins, and R. L. Brownell Jr. | year = 2001 | title = Evolution of river dolphins | journal = Proceedings of the Royal Society of London Series B: Biological Sciences| volume = 268 | issue = 1466 | pages = 549–556 | doi = 10.1098/rspb.2000.1385 | pmid = 11296868 | pmc = 1088639}}</ref> |
The species was described by [[Henri Marie Ducrotay de Blainville]] in 1817. Rice's 1998 classification<ref name=Rice>{{cite book | author = Rice, D. W. | year = 1998 | title = Marine mammals of the world: systematics and distribution | publisher = Society of Marine Mammalogy Special Publication Number 4 | pages = 231}}</ref> lists a single species, ''Inia geoffrensis'' in the genus ''Inia'', with three recognized subspecies. Some older classifications, as well as some recent publications,<ref name=Martinez-Aguero>{{cite journal | author = Martínez-Agüero, M., S. Flores-Ramírez, and M. Ruiz-García | year = 2006 | title = First report of major histocompatibility complex class II loci from the Amazon pink river dolphin (genus ''Inia'') | journal = Genetics and Molecular Research| volume = 5 | pages = 421–431 | url = http://www.funpecrp.com.br/gmr/year2006/vol3-5/pdf/gmr0202.pdf | pmid = 17117356 | issue = 3}}</ref> listed the ''boliviensis'' population as a separate species. In 2012 the [[Society for Marine Mammalogy]]<ref name="MMS">"[http://www.marinemammalscience.org/index.php?option=com_content&view=article&id=645&Itemid=340]" Committee on Taxonomy. 2012. List of marine mammal species and subspecies. Society for Marine Mammalogy, www.marinemammalscience.org, consulted on May, 6 2012. </ref> began considering the Bolivian (''Inia geoffrensis boliviensis'') and Amazonian (''Inia geoffrensis geoffrensis'') subspecies as full species ''Inia boliviensis'' and ''Inia geoffrensis'', respectively; however, much of the scientific community, including the [[IUCN]],<ref name="iucn"/> consider the ''boliviensis'' population to be a subspecies of ''Inia geoffrensis''. The genus ''Inia'' separated from its sister taxon during the Miocene epoch.<ref name=Hamilton>{{cite journal | author = Hamilton, H., S. Caballero, A. G. Collins, and R. L. Brownell Jr. | year = 2001 | title = Evolution of river dolphins | journal = Proceedings of the Royal Society of London Series B: Biological Sciences| volume = 268 | issue = 1466 | pages = 549–556 | doi = 10.1098/rspb.2000.1385 | pmid = 11296868 | pmc = 1088639}}</ref> |
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The two currently recognized species are: |
The two currently recognized species are: |
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*''[[ |
*''[[Amazon river dolphin|I. g. geoffrensis]]'' — distributed in the Amazon and Araguaia/Tocantins basins (excluding the [[Madeira River]] drainage, upstream of the Teotonio Rapids in [[Rondônia]]) |
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*''[[Inia geoffrensis humboldtiana|I. g. humboldtiana]]'' — distributed in the Orinoco basin |
*''[[Inia geoffrensis humboldtiana|I. g. humboldtiana]]'' — distributed in the Orinoco basin |
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*''[[Bolivian |
*''[[Bolivian river dolphin|I. boliviensis]]'' — distributed in the Bolivian subbasin of the Amazon basin upstream of the Teotonio Rapids in [[Rondônia]] |
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==Ecology== |
==Ecology== |
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Revision as of 14:55, 6 May 2012
| Amazon river dolphin | |
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| Family: | Gray, 1846
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| Species: | I. geoffrensis
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| Inia geoffrensis Blainville, 1817
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| Amazon river dolphin range | |
Inia geoffrensis, commonly known as the Amazon river dolphin, is a freshwater river dolphin endemic to the Orinoco, Amazon and Araguaia/Tocantins River systems of Brazil, Peru, Ecuador, Colombia and Venezuela. It is listed as Endangered by the IUCN due to pollution, overfishing, excessive boat traffic and habitat loss.
Other common names of the species include boto, lo lo annaaaa, boto cor-de-rosa, bouto, and pink dolphin.[1]
Description
The Amazon river dolphin is one of a handful of river dolphins included in the paraphyletic group classified as the superfamily Platanistoidea. Although not a large cetacean in general terms, this dolphin is the largest cetacean to spend most of its life in freshwater; it can grow larger than a human. Body length can range from 1.53 to 2.4 m (5.0 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 lb). The largest male dolphins can range up to 2.0 m (6.6 ft) in length and weigh 94 kg (207 lb).[2][3]
They have unfused neck vertebrae, enabling them to turn their heads 180 degrees. They possess long beaks which contain 24 to 34 conical and molar-type teeth on each side of the jaws.[4]
Taxonomy
The species was described by Henri Marie Ducrotay de Blainville in 1817. Rice's 1998 classification[5] lists a single species, Inia geoffrensis in the genus Inia, with three recognized subspecies. Some older classifications, as well as some recent publications,[6] listed the boliviensis population as a separate species. In 2012 the Society for Marine Mammalogy[7] began considering the Bolivian (Inia geoffrensis boliviensis) and Amazonian (Inia geoffrensis geoffrensis) subspecies as full species Inia boliviensis and Inia geoffrensis, respectively; however, much of the scientific community, including the IUCN,[1] consider the boliviensis population to be a subspecies of Inia geoffrensis. The genus Inia separated from its sister taxon during the Miocene epoch.[8]
The two currently recognized species are:
- I. g. geoffrensis — distributed in the Amazon and Araguaia/Tocantins basins (excluding the Madeira River drainage, upstream of the Teotonio Rapids in Rondônia)
- I. g. humboldtiana — distributed in the Orinoco basin
- I. boliviensis — distributed in the Bolivian subbasin of the Amazon basin upstream of the Teotonio Rapids in Rondônia
Ecology
The Amazon river dolphin is found throughout the Amazon 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. They feed on crustaceans, crabs, small turtles, catfish, piranha, shrimp, and other fish.[4]
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.[4]
The young follow their parents closely for a few months, and often two adults are seen swimming with two or more small juveniles.
Conservation
The Amazon river dolphin is listed on appendix II[9] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix II[9] as it has an unfavorable conservation status or would benefit significantly from international co-operation organized by tailored agreements.
In popular culture
In traditional Amazon River 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.[10] 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.[11] Others believe the myth served (and still serves) as a way of hiding the incestuous relations which are quite common in some small, isolated communities along the river.[citation needed] 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.[11] These may or may not be accompanied by the intervention of a priest. A recent study has shown, 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 far from the coast, many, if not most, of the fetishes are derived from domestic animals such as sheep and pigs.[12]
The 1987 Brazilian film Ele, o Boto is a supernatural romance featuring an Amazon river dolphin which has a son by a young woman.
See also
References
- ^ a b c Template:IUCN2011.2 Database entry includes a lengthy justification of why this species is data-deficient. Cite error: The named reference "iucn" was defined multiple times with different content (see the help page).
- ^ "Animal Info - Boto (Amazon river dolphin)". Animal Info - Endangered Animals. June 7, 2006. Retrieved December 6, 2011.
- ^ Robin C. Best & Vera M.F. da Silva (1993). "Inia geoffrensis" (PDF). Mammalian Species (426). The American Society of Mammalogists: 1–8.
- ^ a b c American Cetacean Society Fact Sheet. "Boto (Amazon river dolphin)". American Cetacean Society. Retrieved December 6, 2011.
- ^ Rice, D. W. (1998). Marine mammals of the world: systematics and distribution. Society of Marine Mammalogy Special Publication Number 4. p. 231.
- ^ Martínez-Agüero, M., S. Flores-Ramírez, and M. Ruiz-García (2006). "First report of major histocompatibility complex class II loci from the Amazon pink river dolphin (genus Inia)" (PDF). Genetics and Molecular Research. 5 (3): 421–431. PMID 17117356.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ "[1]" Committee on Taxonomy. 2012. List of marine mammal species and subspecies. Society for Marine Mammalogy, www.marinemammalscience.org, consulted on May, 6 2012.
- ^ Hamilton, H., S. Caballero, A. G. Collins, and R. L. Brownell Jr. (2001). "Evolution of river dolphins". Proceedings of the Royal Society of London Series B: Biological Sciences. 268 (1466): 549–556. doi:10.1098/rspb.2000.1385. PMC 1088639. PMID 11296868.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ 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.
- ^ Megan Balanck. "Whales and Dolphins". Ancientspiral.com. Retrieved December 6, 2011.
- ^ a b M. A. Cravalho (1999). "Shameless creatures: An ethnozoology of the Amazon river dolphin". Ethnology. 38 (1): 47–58. doi:10.2307/3774086.
- ^ Gravena, W., T. Hrbek, V.M.F. da Silva, and I.P. Farias (2008). "Amazon river dolphin love fetishes: From folklore to molecular forensics". Marine Mammal Science. 24: 969–978. doi:10.1111/j.1748-7692.2008.00237.x.
{{cite journal}}: CS1 maint: multiple names: authors list (link)
External links
- 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
- 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