Golden viscacha rat

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Golden viscacha rat
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Octodontidae
Genus: Pipanacoctomys
Mares, Braun, Barquez, and Díaz, 2000
Species:
P. aureus
Binomial name
Pipanacoctomys aureus
Mares, Braun, Barquez, and Díaz, 2000

The golden viscacha rat or golden vizcacha rat (Pipanacoctomys aureus) is the single species of the genus Pipanacoctomys of the rodent family Octodontidae. [2] It has 92 chromosomes and has been regarded as tetraploid (4x = 2n). [3] This octodontid and its sister-species, the plains viscacha rat (Tympanoctomys barrerae) (2n = 102), may have arisen from the diploid mountain viscacha rat (Octomys mimax), [3] (2x = 2n = 56) as a result of the doubling and subsequent loss of some chromosomes. However, some genetic studies have rejected any polyploidism in mammals as unlikely, and suggest that amplification and dispersion of repetitive sequences best explain the large genome size. [4]

Contents

Description

The golden viscacha rat grows to a head-and-body length of about 170 millimetres (7 in) with a tufted tail of about 140 millimetres (6 in). The dorsal fur is golden-blond and the underparts are white. [5]

Distribution and habitat

The species is known from Catamarca Province of northwestern Argentina, where specimens are known only from the Salar de Pipanaco, a salt flat. This habitat consists largely of low, salt-loving shrubs, and the soil consists of sand with high levels of salt. It feeds on the halophytic plants growing there. [6] The genus is named after the locale, with “octo” being a reference to the figure-eight ridge on its cheek tooth.

Status

The golden viscacha rat is only found within a very restricted area totalling less than 100 square kilometres (39 sq mi) and it actually occupies only about one tenth of that area. It lives among the salt-loving plants that live between the salt pans and the desert. It is threatened by conversion of its very restricted habitat to agricultural use, for the growing of olives, and its population trend is downwards. The International Union for Conservation of Nature has rated its conservation status as "critically endangered". [1]

Related Research Articles

<span class="mw-page-title-main">Ploidy</span> Number of sets of chromosomes in a cell

Ploidy is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present : monoploid, diploid, triploid, tetraploid, pentaploid, hexaploid, heptaploid or septaploid, etc. The generic term polyploid is often used to describe cells with three or more chromosome sets.

Kirchner, a surname of German origin, from the Middle High German word, 'kirchenaere'. Kirchner originated as an occupational surname for a church worker, such as a priest, church assistant or a church property administrator. Notable people with the name include:

<span class="mw-page-title-main">Los Chalchaleros</span>

Los Chalchaleros were an Argentine musical folkloric ensemble consisting of four men, and one of the most famous folk singers in the history of Latin America. The group was established in 1948 in the northern province of Salta. It was named after a local song-bird, the chalchalero. They left the stages and recording in 2003.

The aquatic rat, Ecuador fish-eating rat, fish-eating rat or Ecuadoran ichthyomyine is a South American species of semiaquatic rodent in the family Cricetidae. It is the only species in the genus Anotomys. This species is currently considered endangered. It is thought to be nocturnal and feeds on aquatic arthropods and insects. It is found in small ranges along the Andes.

Pittier's crab-eating rat is a species of semiaquatic rodent in the family Cricetidae. It is endemic to Venezuela. The natural habitats of this species are rivers and swamps. Its karyotype has 2n = 92 and FNa = 98. This was previously thought to be the highest chromosome number known for a mammal, but it has since been found that the plains viscacha rat or red viscacha rat has 4x = 2n = 102.

Nephelomys auriventer, also known as the golden-bellied oryzomys or Ecuadorian rice rat, is a species of rodent in the genus Nephelomys of family Cricetidae. Oldfield Thomas originally described it, in 1899, as a species of Oryzomys, Oryzomys auriventer, and considered it most similar to Oryzomys aureus. In 1926, a subspecies was described from an Ecuadorian locality, Oryzomys auriventer nimbosus, and it was suggested that O. auriventer was closely related to O. albigularis. This proposal was formalized in 1961 by including O. auriventer within the species O. albigularis, but by 1976 O. auriventer was recognized again as a separate species. In 2006, Oryzomys albigularis and related species, including O. auriventer, were transferred to the new genus Nephelomys. Simultaneously, the former subspecies nimbosus was recognized as a separate species, Nephelomys nimbosus.

<span class="mw-page-title-main">Chisel-toothed kangaroo rat</span> Species of rodent

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The mountain viscacha rat or mountain vizcacha rat, historically viscacha rat or vizcacha rat, is a species of rodent in the family Octodontidae. It is endemic to Argentina.

<span class="mw-page-title-main">Plains viscacha rat</span> Species of rodent

The plains viscacha rat, plains vizcacha rat, red viscacha rat, or red vizcacha rat is a species of rodent in the family Octodontidae native to Argentina. It is one of three species in the genus Tympanoctomys.

<i>Tympanoctomys</i> Genus of rodents

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<span class="mw-page-title-main">Octodontidae</span> Family of rodents

Octodontidae is a family of rodents, restricted to southwestern South America. Fourteen species of octodontid are recognised, arranged in seven genera. The best known species is the common degu, Octodon degus.

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The Chalchalero viscacha rat or Chalchalero vizcacha rat is a species of caviomorph rodent in the family Octodontidae. It was formerly considered to be monotypic within the genus Salinoctomys, but has been shown by genetic analysis to nest within Tympanoctomys, and in particular, within the variation of T. barrerae. The species is endemic to a small area of northwestern Argentina, where it lives in shrublands bordering the salt flats of the Salinas Grandes. Its diet consists of halophyte plants. It is named after an Argentine musical group, Los Chalchaleros, whose songs were popular with its discoverers.

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Kirchner's viscacha rat or Kirchner's vizcacha rat is a species of rodent in the family Octodontidae described in 2014. It is one of two species in the genus Tympanoctomys. That species is endemic to Chubut Province in the central western Argentina, where it has a fragmented range. Its natural habitat is desert scrubland, dunes and salt flats, where it eats halophyte plants. It is a solitary, nocturnal rodent that constructs large mounds with complex burrows. The species was named in honor of both Cristina Fernández de Kirchner and Néstor Kirchner, presidents of Argentina.

<span class="mw-page-title-main">Argentine Monte</span>

The Argentine Monte (NT0802), or Low Monte, is an ecoregion of dry thorn scrub and grasslands in Argentina. It is one of the driest regions in the country. Human settlements are mainly near water supplies such as rivers or oases. Deforestation and over-grazing around these settlements have caused desertification.

<span class="mw-page-title-main">High Monte</span>

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<span class="mw-page-title-main">Saharan halophytics</span> Ecoregion (WWF)

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References

  1. 1 2 Roach, N. (2016). "Tympanoctomys aureus". IUCN Red List of Threatened Species . 2016: e.T136557A78324400. Retrieved 30 January 2020.
  2. Woods, C.A.; Kilpatrick, C.W. (2005). "Infraorder Hystricognathi". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 1572–1573. ISBN   978-0-8018-8221-0. OCLC   62265494.
  3. 1 2 Gallardo, M. H. et al. (2004). Whole-genome duplications in South American desert rodents (Octodontidae) Archived 2012-04-25 at the Wayback Machine . Biological Journal of the Linnean Society, 82, 443-451.
  4. Svartman, Marta; Stone, Gary; Stanyon, Roscoe (2005). "Molecular cytogenetics discards polyploidy in mammals". Genomics. 85 (4): 425–30. doi:10.1016/j.ygeno.2004.12.004. PMID   15780745.
  5. Mares, M. A.; Braun, J. K.; Barquez, R. M.; Díaz, M. M. (2000). "Two new genera and species of halophytic desert mammals from isolated salt flats in Argentina" (PDF). Occasional Papers, Museum of Texas Tech University. 203: 1–27. Archived from the original (PDF) on 2012-02-17. Retrieved 2011-03-29.
  6. Mares, Michael A. (1 November 2003). "Desert dreams: seeking the secret mammals of the salt pans - Naturalist at Large" (PDF). Natural History : 29–34.