Slender shrew
Sorex Gracillimus is a shrew of the genus Rotzahnspitzmäuse ( Sorex ). It occurs in parts of Russia, including Sakhalin and of the Kuril Islands, the northern part of the People's Republic of China, Korea and Japan.
Features
With a head-body length of 4.8 to 5.2 centimeters Sorex Gracillimus one of the medium-sized shrew species. The tail reaches a length of 37-43 millimeters - making it only slightly shorter than the rest of the body - the hind foot 10 to 11 millimeters.
The skull has a total length of up to 17 millimeters. Like most species of the genus has the kind in the maxilla per half an incisor ( incisor ) and then five unicuspid teeth, a Vorbackenzahn ( premolar ) and three molars ( Molar ). In the mandible, it has, however, a single canine ( canine ) behind the incisor. Overall, the animals thus have a dentition of 32 teeth. The roots of teeth are stained red as with most Rotzahnspitzmäusen. The second single pointed teeth of the upper jaw is significantly larger than the third, and usually smaller than the first. Compared to most representatives of S. minutus group of the skull is nearly round instead of oval and it begins very abruptly behind the rostrum.
The genome of Sorex Gracillimus consists of a diploid chromosome complement of 2n = 36 (FN = 62).
Dissemination
The distribution area of Sorex Gracillimus is located in the northwest corner of the Asian continent and the islands. The species is found in parts of Russia, including Sakhalin and of the Kuril Islands, the northern part of the People's Republic of China, Korea and Japan. In China, the occurrence restricted to the far north in the provinces of Heilongjiang, Jilin and Nei Mongol. In Japan, the species lives on the islands of Shikotan, Hokkaido, Rishiri and Rebun.
Way of life
Sorex Gracillimus lives in the greater part of their range in coniferous forests in mountainous regions, but it also occurs in lowland forests, grasslands and bamboo forests. The densest occurrences are documented from mixed forest stands and riparian forests along rivers, while avoiding short- grass pastures and fields. In the secondary forest, the densities are larger than in the original boreal coniferous forest (taiga ). In most parts of its range the species is allopatric with Sorex minutus.
Like all shrews feed on this species of invertebrates, especially of prey of the scatter cushions and the top soil layers, such as earthworms and insects and their larvae. The breeding season extends from May to October, the females give birth from one to eight, on average, six pups.
System
Sorex Gracillimus is classified as a separate species within the genus of Rotzahnspitzmäuse ( Sorex ), which consists of about 80 species. The first scientific description comes from Thomas from 1907, which described an individual from the Russian island of Sakhalin, together with the type of discovered there too Sorex daphaenodon. Within the genus, the species is classified in the subgenus Sorex and S. Gracillimus group attributed. Some of them were assigned to the species S. minutus, but does because of numerous features today as an independent art
Within the species Sorex Gracillimus hyojironis, Sorex Gracillimus minor and Sorex Gracillimus natalae four other subspecies, in addition to the nominate Sorex Gracillimus Gracillimus Sorex Gracillimus granti, distinguished.
Threat and protection
The type comes up in their area of distribution on the Asian mainland regularly but not frequently. On the island of Sakhalin and the Kuriles Sorex Gracillimus other hand, is the most common type in Japan, she comes to the east and north before regular basis, but not in the south and west.
Sorex Gracillimus is classified by the International Union for Conservation of Nature and Natural Resources (IUCN ) due to the relatively large distribution area and the large populations as well as the non-existent threat inventory as not at risk ( least concern ).