Mountain shrew
| Mountain shrew | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Nectogale | ||||||||||||
| Milne-Edwards , 1870 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Nectogale elegans | ||||||||||||
| Milne-Edwards , 1870 |
The mountain shrew ( Nectogale elegans ) is a species of shrew from Asia that has adapted to aquatic life . It is the only species in the genus Nectogale .
features
general characteristics
These shrews reach a head-torso length of 9 to 11.5 centimeters, a tail length of about 10 centimeters and a weight of 25 to 45 grams. The soft, water-repellent fur of this shrew is dark gray on the upper side and interspersed with individual white hairs, the sharply defined sides of the body and the underside are light to white gray. As with the water shrews, the paws are provided with a bristle-like hairline and also have small webbed feet . Disc-like balls on the soles of the feet are probably used for a better grip when crossing wet stones or to hold the prey. The body is streamlined, the ears are small and completely hidden in the fur. The tail has ridges made of firm hair on the sides, which change the cross section of the tail from a square base to triangular to flat at the end, making it a rowing tool.
In size, the species corresponds roughly to the Himalayan water shrew ( Chimarrogale himalayica ), but it is clearly recognizable due to the webbed feet and tail.
Features of the skull and skeleton
The skull has a maximum width in the area of the zygomatic arches of about 15 to 16 millimeters. It is built flat, the skull is wide and flat and narrows towards the back.
| 1 | · | 3 | · | 1 | · | 3 | = 38 |
| 1 | · | 1 | · | 1 | · | 3 |
The species has a half per maxillary incisor (incisor) and then three comparatively long unicuspid formed teeth, a Vorbackenzahn (premolar) and three molars (molar). In the lower jaw, however, it has a single canine behind the incisor. In total, the animals have a set of 28 teeth. Among the single-pointed teeth, the first two are about the same length, the third is significantly shorter. The tooth roots are colored red as in most red-toothed shrews.
Genome
The genome of the mitochondrial DNA of the mountain shrew was completely sequenced and published in 2013.
Distribution area
The range of the mountain brook shrews is in northern South Asia and includes Tibet and the adjacent Chinese provinces ( Shaanxi , Gansu , Qinghai , Sichuan , Yunnan and Xizang ) as well as parts of Nepal , the Indian state of Sikkim , Bhutan and northern Myanmar . It lives along rivers in mountainous regions at altitudes of 900 to 2270 meters.
Way of life
Compared to all other species of shrew, the mountain shrew is best adapted to life in the water and is the only permanently aquatic species. It lives in fast-flowing mountain streams and is excellent at swimming and diving; These shrews retire to rest in burrows on the river bank.
The diet consists of aquatic insects and small fish that are hunted and preyed mainly during the day. When hunting, for example, it swims against the current and examines stones and branches for prey, after which it drifts into calmer and deeper water and dives there for food.
Systematics
The mountain brook shrew is classified as an independent and only species within the monotypical genus Nectogale . The first scientific description comes from Henri Milne Edwards from 1870, who described the species from Baoxing in Sichuan Province , People's Republic of China. Together with some closely related genera, it forms the tribe Nectogalini.
Apart from the nominate form Nectogale elegans elegans, no further subspecies are distinguished within the species .
Threat and protection
The mountain brook shrew is currently classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as not endangered ("least concern") due to its large distribution area and the assumed large populations . Concrete population numbers and threats to the species are not known; a potential hazard could arise from the clearing of forests for logging and conversion into agricultural land.
supporting documents
- ↑ a b c d e f g Robert S. Hoffmann, Darrin Lunde: Genus Nectogale. In: Andrew T. Smith , Yan Xie: A Guide to the Mammals of China. Princeton University Press, Princeton NJ 2008, ISBN 978-0-691-09984-2 , pp. 311 f.
- ↑ Ting Huang, Chaochao Yan, Zheng Tan, Feiyun Tu, Bisong Yue, Xiuyue Zhang: Complete mitochondrial genome sequence of Nectogale elegans. In: Mitochondrial DNA. June 2013, ISSN 1940-1736 , doi : 10.3109 / 19401736.2013.800490 , PMID 23795853 .
- ↑ a b c d Nectogale elegans in the Red List of Threatened Species of the IUCN 2013.1. Posted by: S. Molur, 2008. Retrieved October 13, 2013.
- ↑ a b c Nectogale elegans . 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 .
- ^ Nectogale . 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 .
literature
- Ronald M. Nowak: Walker's Mammals of the World. 2 volumes. 6th edition. Johns Hopkins University Press, Baltimore MD et al. 1999, ISBN 0-8018-5789-9 .
- Robert S. Hoffmann, Darrin Lunde: Genus Nectogale. In: Andrew T. Smith , Yan Xie: A Guide to the Mammals of China. Princeton University Press, Princeton NJ 2008, ISBN 978-0-691-09984-2 , pp. 311 f.
Web links
- Nectogale elegans inthe IUCN 2013 Red List of Threatened Species . Posted by: S. Molur, 2008. Retrieved October 13, 2013.
- Illustration
