Secrets of the Underground Vietnam: an Underestimated Species Diversity of Asian Moles (Lipotyphla: Talpidae: Euroscaptor)

Abstract

A study of the Southeast Asian moles of the genus Euroscaptor based on a combined approach, viz. DNA sequence data combined with a multivariate analysis of cranial characters, has revealed a high cryptic diversity of the group. An analysis of mitochondrial cytochrome b gene and five nuclear genes has revealed two deeply divergent clades: the western one (E. klossi + E. malayana + E. longirostris from Sichuan + Euroscaptor spp. from northern Vietnam and Yunnan, China), and the eastern one (E. parvidens s.l. + E. subanura). The pattern of genetic variation in the genus Euroscaptor discovered in the present study provides support for the existence of several cryptic lineages that could be treated as distinct species based on their genetic and morphological distinctness and geographical distribution. The moles from southern China and northern Vietnam form three distinct groups. The specimens from Sichuan (including the one collected from the type locality of E. longirostris) were clearly distinct from the northwestern Vietnam and Yunnan samples that were previously attributed to this species. We argue that the real distribution of E. longirostris is restricted to Sichuan, northward of Yangtze River, whereas the populations occurring southward of this isolation barrier evidently represent a new species Euroscaptor orlovi sp. nov. (northwestern Vietnam and Yunnan, southern China). Moreover, Red River that divides the western and eastern parts of northern Vietnam beyond doubt separates the population of E. orlovi from the moles occurring in northeastern Vietnam (Vinh Phuc and Cao Bang provinces); the latter are described here as Euroscaptor kuznetsovi sp. nov. Yet, genetic data are in favour of a close affinity of E. subanura with E. parvidens. A combined analysis of both genetic and morphological data has revealed a strong geographic segregation of E. parvidens samples. The populations from Dalat Plateau (southern Vietnam), including the moles from Loc Bao, Bi Dup and Chu Yang Sin, form a well-supported clade and can be considered true E. parvidens. The specimens from central Vietnam (Kon Tum and Quang Nam provinces) are significantly different from them, yet their monophyly has been supported by the mtDNA only. The moles from central Vietnam have been described here as a new subspecies Euroscaptor parvidens ngoclinhensis ssp. nov. All the studied samples of E. subanura have shown a low genetic and morphological variability despite their wide geographic range.