Azara Comb rat

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Azara Comb rat
Systematics
Subordination : Porcupine relatives (Hystricomorpha)
Partial order : Hystricognathi
without rank: Guinea Pig Relatives (Caviomorpha)
Family : Comb rats (Ctenomyidae)
Genre : Comb rats ( Ctenomys )
Type : Azara Comb rat
Scientific name
Ctenomys azarae
Thomas , 1903

The azara crested rat ( Ctenomys azarae ) is a type of crested rat . The species occurs in central Argentina , where it has been recorded in the provinces of Mendoza , San Luis and La Pampa .

features

The Azara crested rat reaches a total length of 15.8 centimeters and a tail length of 7.7 centimeters; Information on weight is not available. The rear foot length is 35 millimeters with the claw. It is a comparatively small species of the genus. The back color is monochrome brown, the belly color is a little lighter sand-colored brown. The animals have no darker spots in the back fur or white spots in the peritoneum. They can be a little darker on the muzzle.

The skull of the type is 42 millimeters long, the width in the area of ​​the zygomatic arches 26 millimeters and in the interocular area 8.6 millimeters. Its size and shape correspond to that of the Mendoza comb rat ( Ctenomys mendocinus ), but it is narrower, slightly longer and not so flattened. The nasal bones are short and narrow and the tympanic bladders are slightly more swollen than those of the Mendoza comb rat.

The karyotype consists of a double set of chromosomes of 2n = 46, 47 or 48 chromosomes (FN = 68 to 74). The sperm are slightly asymmetrical.

distribution

The distribution area of ​​the Azara crested rat is limited to central Argentina , where it has only been recorded as endemic in the provinces of Mendoza , San Luis and La Pampa .

Way of life

There is very little information available about the way of life of the azara crested rat, as is the case with most species of crested rats. Like all comb rats, it lives largely underground in tunnel systems that it creates in sandy soils on slopes or in open forests in the pampas and adjacent ecoregions. The animals eat vegetarian food from the available plants, especially from above-ground parts of grass and leaves. They are loners (solitary).

Systematics

The Azara crested rat is classified as an independent species within the genus of crested rats ( Ctenomys ), which consists of about 70 species. The first scientific description of the species comes from the British zoologist Oldfield Thomas from 1903, who described it using a full-grown male from the "Province of Buenos Ayres in the central Pampas, 780 kilometers southwest of the capital" in Argentina, which is the General Acha region in the department of Utracán in the province of La Pampa. The original description stated Sapucay in Paraguay as the site , but Oldfield corrected this in the same year. On the basis of molecular biological data, the species is assigned to the mendocinus group around the Mendoza comb rat ( Ctenomys mendocinus ). In some cases, the Azara comb rat was synonymous with the Porteous comb rat ( Ctenomys porteousi ) with the Mendoza comb rat because they have identical G-band patterns of the chromosomes and share a common polymorphism .

Apart from the nominate form, no subspecies are distinguished within the species . The species was named after Félix de Azara because of his work on the mammals of Paraguay.

Status, threat and protection

The Azara Comb rat is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as threatened ("endangered"). This is justified with the comparatively small usable distribution area of ​​about 104 km 2 and the fragmentation of the populations within the area. The main threat is considered to be the decline in available habitats due to the expansion of agriculture.

supporting documents

  1. ↑ a b c d e f g h i Azara’s Tuco-tuco. In: TRO Freitas: Family Ctenomyidae In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (editor): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, p. 532. ISBN 978-84-941892-3-4 .
  2. ↑ a b c d Oldfield Thomas : New species of Oxymycterus, Thrichomys, and Ctenomys from S. America. The Annals and magazine of natural history; Zoology, Botany, and Geology Vol. 11, series 7; Pp. 226-229. ( Digitized version )
  3. ↑ a b c Ctenomys azarae . In: Don E. Wilson , DeeAnn M. Reeder (Eds.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
  4. ↑ a b Ctenomys azarae in the endangered Red List species the IUCN 2019. Posted by: CJ Bidau, 2016. Retrieved on 11 May 2020th

literature

  • Azara's Tuco-tuco. In: TRO Freitas: Family Ctenomyidae In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (editor): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, p. 532. ISBN 978-84-941892-3-4 .

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