New record of Joffre's pipistrelle, Mirostrellusjoffrei (Chiroptera, Vespertilionidae), in China.

Background:Mirostrellusjoffrei Thomas, 1915 is the sole species within the genus Mirostrellus and its occurrence is notably rare in China. Despite the recent discovery of four previously unreported specimens from western Yunnan, China (Zaoteng River, 25.31°N, 98.80°E, altitude 1451 m) at the National Museum of Prague in the Czech Republic, comprehensive descriptions or detailed accounts of this species within China have yet to be published. New information:During a field expedition within the Guanyinshan Provincial Nature Reserve, Yuanyang, Yunnan, China, a bat was captured using a mist net. The specimen was of moderate size, with its ventral surface presenting a golden-brown hue and its dorsal surface ranging from dark brown to obsidian. The forearm measured 37.31 mm, while the fifth digit was conspicuously diminished in comparison to the others. The snout was robust, featuring prominent buccal glands. It was characterised by a well-developed upper frame and a barely visible low sagittal crest. The upper canines possessed well-developed posterior cusps. The dentition comprised two upper and two lower premolars, with the first upper premolar being notably small and the lower molars being distinctly myotodont. These attributes correspond with the known traits of Mirostrellusjoffrei. Phylogenetically, the sequence of this specimen clustered with that of M.joffrei, forming an independent clade. Through an examination of its morphological characteristics and a phylogenetic analysis of the mitochondrial cytochrome b (Cyt b), cytochrome oxidase subunit I (COI) and recombination activating gene 2 (RAG2) sequences, we identified the specimen as M.joffrei, thus confirming the presence of Joffre's pipistrelle in China.