Argentine crested rat

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Argentine crested rat
Systematics
Subordination : Porcupine relatives (Hystricomorpha)
Partial order : Hystricognathi
without rank: Guinea Pig Relatives (Caviomorpha)
Family : Comb rats (Ctenomyidae)
Genre : Comb rats ( Ctenomys )
Type : Argentine crested rat
Scientific name
Ctenomys argentinus
Contreras & Berry , 1982

The Argentine crested rat ( Ctenomys argentinus ) is a species of crested rat . The species is endemic to the north of Argentina .

features

The Argentine crested rat reaches a total length of about 26 centimeters and an average tail length of 8.4 centimeters, weight information is not available. It is a medium-sized species of the genus. The back color is brown and becomes lighter yellowish-brown on the sides of the body. The ventral side is pale gray-brown. A dark center line extends from the muzzle over the face, the top of the head and the back to the base of the tail. It starts as a narrow line, widens on the top of the head and then narrows again. The animals also have a light-colored collar in the neck area.

The skull is strongly built and the adult animals have strong skull crests. The snout is relatively large compared to other species. The upper incisors are slightly protruding ( proodont ). The nasal bones are very narrow, the zygomatic arches are comparatively narrow. The timpani are comparatively small and hardly inflated. The penis bone is flat with a convex dorsal side and an enlarged front, proximal, end.

The karyotype consists of a double chromosome set of 2n = 44 (FN = 50, 51 and 52 due to an inversion - polymorphism ) chromosomes. The sperm are symmetrical.

distribution

The distribution area of ​​the Argentine crested rat is limited to the north of Argentina , where the species is endemic . It has been found in the provinces of Formosa , Chaco , Santiago del Estero and Santa Fe .

Way of life

Little information is available about the way of life of the species. Like all crested rats, it lives largely underground in duct systems and feeds on the available vegetation as a vegetarian. The habitat is shaped by the northern Argentine Chaco with dry forests and thorn bush savannas. The animals occur in drier to more humid regions (Chaco Seco and Chaco Húmedo) and live as solitary animals in sandy soils. The distribution is spotty and not extensive, which is attributed, among other things, to regular flooding of the habitats.

Systematics

The Argentine 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 Argentine zoologists Julio Rafael Contreras and Licia M. Berry from 1982. They specified the region around Campo Aráos about 27 kilometers north of Libertador General San Martín as the type locality ; the find height was documented at 2500 meters. Due to its range, the species would be assigned to a species group of different species in the Chaco region; However, molecular biological studies assign them to the tucumanus group around the Tucumán comb rat ( Ctenomys tucumanus ).

Apart from the nominate form, no subspecies are distinguished within the species .

Status, threat and protection

The Argentine Comb rat is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as a type of the warning list ("near threatened"). The classification is justified by the comparatively small distribution area of ​​less than 124 km 2 and the fragmentation of the population into several separate subpopulations. The main threats to this species are habitat loss from the expansion of agricultural land for soybean cultivation and the naturally small and fragmented populations.

supporting documents

  1. ↑ a b c d e f g h i Argentine 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. 517. ISBN 978-84-941892-3-4 .
  2. ↑ MO Ortells, JR Contreras, OA Reig: New Ctenomys karyotypes (Rodentia, Octodontidae) from north-eastern Argentina and from Paraguay confirm the extreme chromosomal multiformity of the genus. Genetica 82, 1990; Pp. 189-201. doi : 10.1007 / BF00056362
  3. ↑ a b c d Ctenomys argentinus in the Red List of Threatened Species of the IUCN 2019. Posted by: CJ Bidau, 2016. Accessed April 14, 2020.
  4. ↑ a b c Ctenomys argentinus . 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 .
  5. ↑ J. Contreras, L. Berry: Ctenomys argentinus, una nueva especie de tuco-tuco procedente de la provincia del Chaco Rep. Arg. (Rod. Oct.). Historia Natural 2 (20), 1982; Pp. 165-173.

literature

  • Argentine 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. 517. ISBN 978-84-941892-3-4 .