Ucayali Water Rat
Encyclopedia
Amphinectomys savamis, also known as the Ucayali Water Rat or Amphibious Rat, is a rodent
from Peru
vian Amazonia. It is placed as the only member of genus Amphinectomys in the tribe Oryzomyini
of family Cricetidae
. It is similar to Nectomys
, but its discoverers considered it to be different enough (with more expansive interdigital webbing and a significantly broader interorbital region) to require its own genus. When it was described as a new genus in 1994, knowledge of the variation within Nectomys was much more limited than it is now, and it has been suggested that the status of the taxon be re-examined considering this new information. The species's karyotype
, 2n = 52, falls within the known range of Nectomys (2n = 38 - 59).
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
from 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....
vian Amazonia. It is placed as the only member of genus Amphinectomys in the tribe Oryzomyini
Oryzomyini
Oryzomyini is a tribe of rodents in the subfamily Sigmodontinae of family Cricetidae. It includes about 120 species in about thirty genera, distributed from the eastern United States to the southernmost parts of South America, including many offshore islands...
of family Cricetidae
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...
. It is similar to Nectomys
Nectomys
Nectomys is a genus of rodent in the tribe Oryzomyini of family Cricetidae. It is closely related to Amphinectomys and was formerly considered congeneric with Sigmodontomys...
, but its discoverers considered it to be different enough (with more expansive interdigital webbing and a significantly broader interorbital region) to require its own genus. When it was described as a new genus in 1994, knowledge of the variation within Nectomys was much more limited than it is now, and it has been suggested that the status of the taxon be re-examined considering this new information. The species's karyotype
Karyotype
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...
, 2n = 52, falls within the known range of Nectomys (2n = 38 - 59).
Literature cited
- Duff, A. and Lawson, A. 2004. Mammals of the World: A checklist. New Haven, Connecticut: Yale University Press, 312 pp. ISBN 071366021X
- Malygin, V.M., Aniskin, V.M., Isaev, S.I. and Milishnikov, A.N. 1994. Amphinectomys savamis Malygin Gen. et sp. n., a new species and a new genus of water rat (Cricetidae, Rodentia) from Peruvian Amazonia. Zoologicheskii Zhurnal 73:195-208.
- Pacheco, V., Zeballos, H. and Vivar, E. 2008. . In IUCN. IUCN Red List of Threatened Species. Version 2009.2. <www.iucnredlist.org>. Downloaded on December 8, 2009.