Multilocus phylogeny and cryptic diversity of white-toothed shrews (Mammalia, Eulipotyphla, Crocidura) in China

Abstract

Background: Crocidura , the most speciose mammalian genus, occurs across much of Asia, Europe and Africa. The taxonomy of Chinese representatives has been studied primarily based on cursory morphological comparisons and their molecular phylogenetic analyses remain unexplored. In order to understand the phylogeny of this group in China, we estimated the first multilocus phylogeny and conducted species delimitation, including taxon sampling throughout their distribution range. Results: We obtained one mitochondrial gene ( cytb ) (~ 1, 134 bp) and three nuclear genes ( ApoB , BRCA1 , RAG1 ) (~ 2, 170 bp) for 132 samples from 57 localities. Molecular analyses identified at least 14 putative species that occur within two major well-supported groups in China. Polyphyletic C. wuchihensis appears to be composed of two putative species. Two subspecies, C. rapax rapax and C. rapax kurodai should be elevated to full species status. A phylogenetic tree based on mitochondrial gene from Asian Crocidura species showed that the C. rapax rapax is embedded within C. attenuata , making the latter a paraphyletic group. Three strongly supported undescribed species ( C. sp.1, C. sp.2 and C. sp.3) are revealed from Zada County of Tibet (Western China), Hongjiang County of Hunan Province (Central China) and Dongyang County of Zhejiang Province (Eastern China), Motuo County of Tibet, respectively. The divergence time estimation suggested that China’s Crocidura species began to diversify during the late Pliocene (3.66 Ma) and the Early Pleistocene (2.29 Ma), followed by a series of diversifications through the Pleistocene. Conclusions: The cryptic diversity found in this study indicated that the number of species is strongly underestimated under the current taxonomy. We propose that the three undescribed species should be evaluated using extensive taxon sampling and comprehensive morphological and morphometric approaches. Climate change since the late Pliocene and the uplift of the Qinghai-Tibet Plateau may result in the diversification and speciation of China’s Crocidura species. In short, the underestimated diversity underlines the need for a taxonomic revision of Chinese Crocidura species.

Molecular phylogeny and taxonomy of the genus Nectogale (Mammalia: Eulipotyphla: Soricidae)

“…For instance, two new species [Neodon medogensis (Liu et al, 2017) and Alpiscaptulus medogensis (Chen et al, 2021)], and a cryptic species of the white-toothed shrews (Crocidura sp. 3) (Chen et al, 2020) were discovered in Medog of Tibet. In addition, Neodon linzhiensis (Liu et al, 2012), Neodon nyalamensis (Liu et al, 2017),…”

“…For instance, two new species [ Neodon medogensis (Liu et al, 2017) and Alpiscaptulus medogensis (Chen et al, 2021)], and a cryptic species of the white‐toothed shrews ( Crocidura sp. 3) (Chen et al, 2020) were discovered in Medog of Tibet. In addition, Neodon linzhiensis (Liu et al, 2012) , Neodon nyalamensis (Liu et al, 2017) , Niviventer fengi (Ge et al, 2021), and Eupetaurus tibetensis (Jackson et al, 2021) were discovered in Gongbujiangda of Tibet, Nyalam of Tibet, Jilong of Tibet, and Gyantse of Tibet, respectively.…”

“…In addition, Neodon linzhiensis (Liu et al, 2012) , Neodon nyalamensis (Liu et al, 2017) , Niviventer fengi (Ge et al, 2021), and Eupetaurus tibetensis (Jackson et al, 2021) were discovered in Gongbujiangda of Tibet, Nyalam of Tibet, Jilong of Tibet, and Gyantse of Tibet, respectively. In addition, molecular analyses identified high genetic diversity in birds ( Garrulax ) (Qu et al, 2011), rodents ( Apodemus ) (Fan et al, 2012), pikas ( Ochotona ) (Koju et al, 2017), and insectivores ( Sorex , Crocidura , Scaptonyx ) (Chen et al, 2015, 2020; He et al, 2019). The complex topography (the huge mountains and deep rivers) and geographic history (the uplift of QTP), along with diversified climate conditions may be relevant to the high species diversity and genetic diversity.…”