New records and an updated checklist of the genus Myotis (Chiroptera, Vespertilionidae) in Xizang, China

Xizang, located on the southwestern Qinghai-Xizang Plateau of China, hosts a mammalian fauna whose true diversity remains incompletely understood. This knowledge gap is particularly pronounced in bat clades with high cryptic diversity such as Myotis (Chiroptera: Vespertilionidae). To clarify species boundaries and diversity patterns of Myotis in this region, we conducted a series of field surveys in border areas of Xizang from 2023 to 2025 and employed an integrative taxonomic approach combining mitochondrial cytochrome b (cyt b) phylogenetic analyses, detailed morphological comparisons, and echolocation calls assessments. Our results confirm the distribution of 9 Myotis species in Xizang, significantly updating its species diversity. Notably, we document Myotis himalaicus and M. sicarius from China for the first time, substantially extending their known distributions. In addition, we critically reassess the occurrence of M. siligorensis and M. longipes, demonstrating that valid records of both species in China are restricted to Xizang, near their type localities in India and Nepal. Consequently, previous records of these taxa from China likely represent misidentifications and necessitate a thorough re-evaluation. Overall, this study establishes a robust taxonomic baseline for future systematic updates and conservation planning in the biogeographically complex region of Xizang.