The tenth member of stout newt (Amphibia: Salamandridae: Pachytriton): Description of a new species from Guangdong, southern China

摘要

Field surveys of less-explored forests often lead to discoveries of new amphibian species. During a series of field surveys in early 2017 at Mt. Lianhua (the Lotus Mountain) of Lianhuashan-Baipenzhu Provincial Nature Reserve in southern China, we found an undocumented population of stout newt, genus Pachytriton. Based on its distinct morphological characters and large genetic divergence from congeners (uncorrected p-distance 5% in either mitochondrial nd2 or cytb sequences), we describe this population as the tenth species of the genus: Pachytriton airobranchiatus sp. nov. It can be distinguished from other members of Pachytriton by a combination of the following morphological characters: prominently elevated distal end of the epibranchial bone showing as two conspicuous protruding bulges behind the head; dorsal coloration can be either spotted or unspotted; bright orange dots absent on dorsum; costal grooves absent between axilla and groin; fingers I and toe I slender, do not forms a volar pad; dorsal tips of fingers and toes brown; and tips of fore-and hind limbs could contact when limbs adpressed against body flank. Phylogenetic analysis grouped the new species with P wuguanfui, P xanthospilos, and P changi. Currently, the new species is known from the type locality and an adjacent mountain peak at about 1000 m elevation. It inhabits small montane streams in broadleaf forests near the top of the mountain.