Range extension and expanded description of Micryletta hekouensis Liu, Hou, Mo & Rao, 2021 (Amphibia, Anura, Microhylidae), with comments on Micryletta of Northern Vietnam

The Paddy frog species Micryletta hekouensis was described based on only two specimens from Nanxi Village, Nanxi Town, Hekou County, Honghe Prefecture, Yunnan Province, China. Herein, we report on new findings and a range extension of this species based on a re-examination of preserved specimens deposited in Duy Tan University (DTU) and Zoological Museum of Lomonosov Moscow State University (ZMMU) collected from Vietnam. All new specimens were previously identified as Micryletta cf. inornata or M. cf. steinegeri. Molecular analyses based on mitochondrial DNA supported the morphological findings. The newly identified specimens have a pairwise divergence of only 0.7% from those of the type series of M. hekouensis, based on the 16s rRNA mtDNA gene. Based on the new information, we confirm the presence of M. hekouensis in Vietnam and update the diagnostic characters of this species and its distribution. We suggest the species should be considered as Near Threatened (NT) following the IUCN’s Red List categories. Further studies reassessing the populations of the Micryletta inornata complex in the Indochinese Region (including Vietnam, Laos, Cambodia, and Thailand) are required.