Collared Comb rat
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Collared Comb rat ( Ctenomys torquatus ) |
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| Ctenomys torquatus | ||||||||||||
| Lichtenstein , 1830 |
The collar-crested rat ( Ctenomys torquatus ) is a type of crested rat . The species occurs in southeastern Brazil as well as in northern and central Uruguay .
features
The collar-comb rat reaches a head-trunk length of 16.7 to 23.0 centimeters for the males and 15.2 to 20.0 centimeters for the females. The tail length is 5.5 to 8.5 centimeters; no specific data are available for weight. The rear foot length with the claw is 28 to 35 millimeters. It is therefore a relatively small species of the genus, with the males usually being a little larger and heavier than the females. The back color is brown-orange and becomes lighter towards the flanks. The ventral side is pale orange-brown with white spots in the armpits and loin. A light, also brown-orange collar is typical of the species; the animals also have lighter spots below and behind the ears. Completely black, melanistic individuals are found in some populations .
The skull is small and less rounded than that of the dwarf crested rat ( Ctenomys minutus ). On the top of the head there are slight bumps and temple ridges, but a real crest is not formed. The upper incisors protrude slightly more ( proodont ) than in the dwarf comb rat . The penis bone (bacculum) is comparatively short with a length of about 0.65 centimeters and it is rounded at both ends.
The karyotype consists of a double set of chromosomes of 2n = 40, 42, 44 or 46 (FN = 72) chromosomes. The sperm are symmetrical.
distribution
The distribution area of the collar-crested rat extends from southeastern Brazil in the south of the state of Rio Grande do Sul to eastern and central Uruguay .
Way of life
As with most species of comb rats, very little information is available about the way of life of the collar rat. Like all comb rats, it lives largely underground in duct systems. As a habitat it uses sandy soils in open fields and in the area of open gallery forests in the pampas . The species is also found in agricultural areas, plantings and also in open urban areas in Montevideo . The animals feed on a generalist vegetarian diet from the available plants, especially grass and leaves.
The animals are solitary (solitary) in adjacent buildings. Reproduction occurs in spring and summer, and the females give birth to 2 to 3 young animals from September to December after a gestation period of around 105 days.
Systematics
The Collared Comb rat is classified as an independent species within the genus of the Comb rats ( Ctenomys ), which consists of about 70 species. The first scientific description of the species comes from the German zoologist Martin Hinrich Lichtenstein from 1830, who described it on the basis of individuals from the range in southern Brazil and Uruguay that is still documented today; the specific locations of the types are unknown. Based on molecular biological data, it is assigned to the torquatus group. It was partially assigned to the Brazilian crested rat ( Ctenomys brasiliensis ) as a subspecies.
Apart from the nominate form, no subspecies are distinguished within the species .
Status, threat and protection
The Collared Comb rat is listed by the International Union for Conservation of Nature and Natural Resources (IUCN) as not endangered ("least concern"). The reason given is the comparatively large distribution area and the assumed large and stable population. Despite its wide geographical distribution, the species is threatened in Brazil. Agriculture has developed rapidly on the sand fields in the central and southern Rio Grande do Sul since the 1960s, with soybean, pine and eucalyptus plantations in particular increasing significantly. It is believed that open-cast coal mining is also a significant threat.
supporting documents
- ↑ a b c d e f g h i j k l Collared 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, pp. 522-523. ISBN 978-84-941892-3-4 .
- ↑ a b c Ctenomys torquatus . 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 .
- ↑ a b c Ctenomys torquatus in the endangered Red List species the IUCN 2019. Posted by: CJ Bidau, 2016. Accessed May 8 2020th
literature
- Collared 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, pp. 522-523. ISBN 978-84-941892-3-4 .
Web links
- Ctenomys torquatus in the endangered Red List species the IUCN 2019. Posted by: CJ Bidau, 2016. Accessed May 8 2020th