Roig Comb rat

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Roig 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 : Roig Comb rat
Scientific name
Ctenomys roigi
Contreras , 1988

The roig- comb rat ( Ctenomys roigi ) is a type of comb- rat . The species is endemic to the northeast of Argentina , where it has only been found in a region along the Río Paraná in the province of Corrientes .

features

The Roig comb rat reaches a total length of 26.0 to 30.0 centimeters with a head-trunk length of 17.6 to 20.0 centimeters and a tail length of 7.6 to 9.9 centimeters, the weight is about 230 Gram. The rear foot length with the claw is 34.5 to 43.8 millimeters. It is a relatively large species of the genus, with the males usually being a little larger and heavier than the females. The back color is brown, with the fur on the back itself being more sandy brown and clay-brown on the flanks, gradually becoming lighter from the head to the torso. The belly of most individuals is cinnamon-colored with creamy white washings and white spots in the armpits and loin area. The top of the head is dark brown from the snout to the nape of the neck, and there is no light collar. The legs and feet are almost white and the tail is covered with individual white hairs and is slightly bicoloured with a darker top and a lighter underside.

The skull is strong and stable. The tympanic cavities are only slightly enlarged and cannot be seen from the top view of the skull. The zygomatic arches are strong and wide spreading. The muzzle region is short and strong with broad nasal bones . The upper incisors clearly protrude ( proodont ). The penis bone (bacculum) is small and spoon-like.

The karyotype consists of a double set of chromosomes of 2n = 48 (FN = 76) chromosomes. The sperm are symmetrical.

distribution

The range of the Roig crested rat is limited to the northeast of Argentina , where the species is only endemic in an area with a length of 12 kilometers along the Río Paraná in the province of Corrientes .

Way of life

As is the case with most species of comb rats, very little information is available about the way of life of the roig crested rat. Like all comb rats, it lives largely underground in duct systems. As a habitat, it uses sandy-loamy soils near rivers, sometimes also in pasture areas. The animals feed on a generalist vegetarian diet from the available plants, especially grass and leaves. They usually feed on tubers, roots and stems underground, or they pluck vegetation from the area around the building and pull it underground.

The animals are solitary (solitary) in adjacent buildings. Reproduction occurs in spring and summer, with about 50% of the females being pregnant or lactating in October. The females only give birth to very small litters, on average with only one or two young animals. In December around 40% of the non-adult animals are offspring from the current year.

Systematics

The Roig comb rat is classified as an independent species within the genus of the comb rats ( Ctenomys ), which consists of around 70 species. The first scientific description of the species comes from the Argentine zoologist Julio Rafael Contreras from 1988, who described it using individuals from Costa Mansión, about 10 kilometers south of Empedrad in the Corrientes province in Argentina. Based on molecular biological data, it is assigned to the torquatus group around the collar-comb rat ( Ctenomys torquatus ).

Apart from the nominate form, no subspecies are distinguished within the species . The species is named after Virgilio Germán Roig .

Status, threat and protection

The Roig Combed Rat is listed as critically endangered by the International Union for Conservation of Nature and Natural Resources (IUCN). The reason given is primarily the very small distribution area with a habitat area of ​​less and 10 km 2 within a total region of a maximum of 96 km 2 . The species is only known from one locality and consists of only one or two populations living close together . The available habitat is threatened by agricultural use and overgrazing.

supporting documents

  1. ↑ a b c d e f g h i j k l Roig’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. 522. ISBN 978-84-941892-3-4 .
  2. ↑ a b Ctenomys roigi . 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 .
  3. ↑ a b Ctenomys roigi in the endangered Red List species the IUCN 2019. Posted by: CJ Bidau, 2019. Accessed May 7, 2020th

literature

  • Roig 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. 522. ISBN 978-84-941892-3-4 .

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