苔原鼩鼱(Sorex tundrensis)在中国分布的首次证实

2008 年8 月利用陷阱法在内蒙古额尔古纳国家级自然保护区获得了4 号鼩鼱类标本,个体皆小, 尾长小于32 mm,貌似姬鼩鼱,颅全长在16. 50 ～17.24 mm 之间,大于姬鼩鼱(15 mm)。为了确证该4 号标本的物种类型,本文测定了它们的线粒体细胞色素b (Cyt b)基因全序列,结合从GenBank 下载的鼩鼱类序列构建系统进化关系。发现测定序列和下载苔原鼩鼱序列很好地聚在一起并形成单系。标本间及与下载的苔原鼩鼱间遗传距离小。从分子角度确证了标本为苔原鼩鼱,证实了苔原鼩鼱在中国的分布。本文对标本进行了描述。

First confirmation of the distribution of tundra shrew(Sorex tundrensis)in China

Four specimens (NM1,NM2,NM3,NM4) of genus the Sorex were trapped by the pitfall trap method in Eerguna National Nature Reserve,Inner Mongolia,China,in August,2008. All specimens are small,with tail lengths less than 32 mm,and resembled S. minutissimus. The length of the condylo-incisive length varied from 16.50 to 17.24 mm , which exceeded that reported for S.minutissimus (15 mm). To identify the taxonomic status of the specimens,we sequenced mitochondrial cytochrome b genes. We combined our data with sequences of Sorex retrieved from GenBank to construct a phylogenetic tree. Our 4 specimens from Inner Mongolia clustered with S. tundrensis, and formed a well supported monophyletic clade. We found that the genetic distances between downloaded S. tundrensis sequences and our sequences were very small. Thus, we consider these four specimens to be S. tundrensis and are a new record of the species in China.