A new species of the genus Boulenophrys (Anura, Megophryidae) from Southwest China

During amphibian surveys conducted at Mt.Daxue Nature Reserve on June 28-30, 2023, we collected specimens of within the genus Boulenophrys. Based on molecular phylogenetic analyses and morphological comparisons, we describe this taxon as a new species from southwestern China.Molecular phylogenetic analyses based on mitochondrial DNA strongly support the new species as a sister species of B. jiangi.

The uncorrected genetic distances between the 16S rRNA and COI genes between the new species and its closest congener were 9.3% and 8.1%, respectively. The new species could be distinguished from its congeners by a combination of the following characters: (1) adult males have a moderate body size (SVL 37.1–40.6 mm), differing from B. jiangi in having longer hindlimbs when adpressed anteriorly—the tibiotarsal articulation reaches the mid-level of the eye when extended (vs. only reaching the area between the tympanum and the eye in B. jiangi); (2) vomerine ridge present and vomerine teeth absent; (3) tongue not notched behind; (4) a small horn-like tubercle at the edge of each upper eyelid; (5) tympanum distinctly visible, rounded; (6) toes lacking lateral fringes and webbing; (7) Distinct relative finger lengths: II < I < V < III in the new species (vs. I < II < V < III in B. jiangi); (8) heels overlapping when thighs are positioned at right angles to the body; (9) tibiotarsal articulation reaching the level of the middle of the eye when leg is stretched forward; (10) an internal single subgular vocal sac in male; (11) dense nuptial spines on dorsal bases of fingers I and II in breeding adult males;(12) Eye diameter (ED) significantly smaller than that of B. jiangi (ED: 4.00±0.28 in the new species vs. 5.00±0.38 in B. jiangi, P < 0.05).