Pearson Comb rat

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Pearson 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 : Pearson Comb rat
Scientific name
Ctenomys pearsoni
Lessa & Langguth , 1983

The Pearson's comb rat ( Ctenomys pearsoni ) is a species of the comb rats . The species is endemic to the south of Uruguay . It resembles the closely related collar-comb rat ( Ctenomys torquatus ) and like this one has a conspicuous collar, but differs from it mainly in the skull morphology.

features

The Pearson comb rat reaches a total length of 24.5 to 27.7 centimeters with a tail length of 7.2 to 8.2 centimeters and a weight of about 165 to 300 grams. It is a medium-sized species of the genus. In terms of coloration, the species largely corresponds to the collar-comb rat with an orange-brown back coloration, lighter body sides and a pale brown belly. As with this one, a light-colored collar is formed in the lower neck area.

The skull is comparatively narrow, flattened and elongated. The top of the forehead is largely flat from the eye area to the skull. The muzzle is elongated, and the upper incisors are slightly protruding ( proodont ). The tympanic bladders are elongated and reach behind the condyles of the head joints .

The karyotype consists of a double set of chromosomes of 2n = 56, 58, 64, 66 and 70 (FN = 77 to 80) chromosomes; there is probably no connection between the different haplotypes and geographical distribution. However, it is unclear whether all studies on the karyotype of this species really relate to this. The sperm are symmetrical.

distribution

The distribution area of ​​the Pearson's comb rat is limited to the south of Uruguay , where the species is endemic only in the area where it was first found near the city of Rocha in the Rocha department to Colonia del Sacramento in the Colonia department along the Uruguay River.

Way of life

There is little information available about the way of life of the Pearson crested rat, as is the case with most species of crested rats. Like all comb rats, it lives largely underground in duct systems. As a habitat, it uses open sandy areas with a variable proportion of clay on the banks or in the surrounding areas of the Río Uruguay. In a generalist vegetarian way, it feeds on the available plants, especially grass and leaves. The species shows a great variety in the construction of its courses; however, there is usually a main corridor of constant depth that forms the main axis of the construction. The tunnels have 5 to 24 exits, an average of thirteen, and vary in length from 70 to 130 centimeters. There are one or two nests of dried grass per tunnel.

The animals are solitary (solitary) and territorial, they defend their territory accordingly against conspecifics. They are polygynous , so a male mates with several females. The reproductive phase takes place from July to September, with the females taking care of their offspring. The young are suckled for a period of about two months and then leave the mother's den. The young females are sexually mature in the year of their birth .

Systematics

The Pearson crested rat is classified as an independent species within the genus of the crested rats ( Ctenomys ), which consists of about 70 species. The first scientific description of the species comes from the Uruguayan zoologists Enrique P. Lessa and Alfredo Langguth from 1983, who described it using individuals from Arroyo Limetas southeast of Carmelo in the Department of Colonia . 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 Pearson comb rat was named after the American zoologist Oliver Payne Pearson (1915-2003).

Status, threat and protection

The Pearson's comb rat is listed by the International Union for Conservation of Nature and Natural Resources (IUCN) as a type of warning list ("near threatened"). The reason given is the very small distribution area with an available habitat area of ​​less than 500 km 2 , which is also shrinking. The main threat to the species population is habitat change; However, it is adaptable and survives even in disturbed habitats, tolerating agriculture and changes on the riverbank.

supporting documents

  1. ↑ a b c d e f g h i j k l Pearson’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 c Ctenomys pearsoni . 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 c Ctenomys pearsoni in the endangered Red List species the IUCN 2019. Posted by: CJ Bidau, 2019. Accessed April 29, 2020th

literature

  • Pearson'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 .

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