A new species of Gracixalus (Amphibia, Anura, Rhacophoridae) from Guizhou Province, China

A new species of small tree frog was discovered in southwestern China, exhibiting morphological differences and molecular divergence. The new species, formally described herein as Gracixalus weii sp. nov., is morphologically distinct from other congeners by body size (SVL 30.1-34.0 mm in males and 35.2-36.0 mm in females). In addition, the head width was larger than the head length, with a distinct tympanum, a brown to beige dorsum, and an inversed Y-shaped dark brown marking. The skin of the dorsal and lateral surfaces of the head, body, and limbs was rough and sparsely scattered with tubercles. The toes showed moderately developed webbing, while finger webbing was rudimentary. Nuptial pads were found on the base of finger I; males had a single subgular vocal sac, with heels overlapping when the legs were at a right angle to the body, and the tibiotarsal articulation reached the mid-eye when the legs were stretched forward. Phylogenetic analyses based on DNA sequences of the mitochondrial 16S rRNA supported the new species as a sister species of G. jinxiuensis. Genetically, the new species diverges from its congeners by 3.4%-14.5% (uncorrected p-distance) and is closest to G. jinxiuensis, which is 3.4%.