Integrative taxonomic evidence for a new species of genus Gracixalus (Anura, Rhacophoridae) from Mao'er Mountain, Guangxi, China

It has been shown that the taxonomy of Gracixalus jinxiuensis species complex is very confusing. In this study, we tested for the taxonomy of Gracixalus species from Mao’er Mountain, Guangxi, China, which was once recorded as G. jinxiuensis, based on molecular, morphological, and bioacoustics evidence. Phylogenetic analyses based on mitochondrial 16 S rRNA sequences indicated that the samples from Mao’er Mountain form a distinct lineage closely related to G. jinxiuensis, G. huaping, and G. weii, and they were assigned into an independent operational taxonomic unit by analysis of species delimitation.

Morphologically, the lineage from Mao’er Mountain can be distinguished from known congeners by a combination of the following characters: SVL 27.5–33.2 mm in males and 38.1‒39.7 mm in females; dorsal surface beige to brown, rough with a few tubercles on dorsum; internal vocal sac; linea masculina absent; nuptial pads present on fingers I and II; tibiotarsal articulation reaching center of eye; heels overlapping when legs at right angle to body; and white tubercles on temporal region, edge of upper and lower jaw, flank, and dorsal surface of limbs.

In addition, bioacoustics analyses showed that the advertisement calls of the population from Mao’er Mountain also differ from advertisement calls of other Gracixalus species. Therefore, we officially described the lineage from Mao’er Mountain as a new species and named it as Gracixalus liusanjieae sp. nov. herein. Including the new species described in this study, now the genus Gracixalus contains 23 species, 12 of which are distributed in China with six known in Guangxi.