Sunday, June 23, 2024

[Herpetology • 2024] Rhacophorus dulongensis • Hidden in the Bamboo: A New Parachuting Frog (Anura: Rhacophoridae: Rhacophorus) from the borderlands of western China, with Comments on the Taxonomy of R. rhodopus

Rhacophorus dulongensis Chen, Lee & Yuan,

in Lee, B. Liu, Ouyang, Ai, X.-L. Liu, He, Huang, Li, Naveen, Yuan et Chen, 2024. 
 Dulongjiang Tree Frog  |  独龙江树蛙  ||  DOI: 10.3897/zse.100.120224

The Gaoligong Mountains are characterized by large variations in elevation and topography, which support high levels of biodiversity and endemism that remain largely understudied. Herein, based on the integration of morphological comparisons and phylogenetic reconstruction, we describe a new species of Rhacophorus from the northern Gaoligong Mountains, Yunnan Province, China. The new species, Rhacophorus dulongensis sp. nov., is morphologically distinguishable from its congeners based on the differences in body size, head length, tibia length, snout and tongue shape, toe webbing formula and coloration, ventral skin texture and coloration, dorsal pattern and coloration, body macroglands, iris coloration, and pattern of markings on flanks. Phylogenetically, it differs from its congeners by uncorrected p-distances of >4.8% for the 16S rRNA gene fragment. Rhacophorus dulongensis sp. nov. is likely to be found in Myanmar, considering its type locality lies close to the China-Myanmar border. The phylogenetic analysis revealed that the “widespread” species, R. rhodopus, is a species complex and a composite of five distinct lineages. The results revealed that R. napoensis is also found in Vietnam, making it a new country record for Vietnam. Interestingly, R. dulongensis sp. nov. likely breeds in bamboo, a hidden behavioral characteristic that makes them easy to overlook. Given the ongoing habitat loss and degradation in the region, further biological exploration is urgently needed in the Gaoligong Mountains as a biodiversity reservoir.

Key Words: Biodiversity hotspot, frog, Gaoligong Mountains, new record species, new species, systematics

Holotype of Rhacophorus dulongensis sp. nov. (ANU010645) in life.
A. Dorsal view; B. Ventral view; C. Dorso-lateral view; D. Ventral surface of the thigh and the cloacal region; E. Plantar view of the left foot; F. Thenar view of the right hand. The blue arrow in D points to large black warts.
Photos by Renda Ai.

 Rhacophorus dulongensis Chen, Lee & Yuan, sp. nov.
Diagnosis: Rhacophorus dulongensis sp. nov. can be distinguished from its congeners by the following combination of morphological characters: (1) body size small (SVL 31.7 mm in male; 35.3 mm in female); (2) head length longer than head width; (3) tibia length shorter than half of snout-vent length; (4) third finger disk smaller in diameter than tympanum; (5) snout pointed without a distinct bulge; (6) the tibiotarsal articulation reaches the eye when hindlimb is stretched along the side of the body; (7) dorsal surface of body uniformly green, and dorsal surface of limbs brown with irregular green patches; (8) belly mostly yellowish, rough, and granular (9) large black warts present on ventral surface of thigh near vent; (10) webs between toes red and webbing formula on toes: I10-12/3II1--21/2III1+-21/3IV21/3-11/3V; (11) black spots at axillary region absent; (12) vomerine teeth weakly developed; (13) iris darkgoldenrod; (14) maxillary teeth distinct; (15) tongue notably notched posteriorly.

Etymology: The specific epithet “dulongensis” is given as a noun in apposition and refers to the name of the Dulongjiang Village, where the new species occurs. We suggest the English common name “Dulongjiang tree frog” and the Chinese common name “独龙江树蛙” (dú lóng jiāng shù wā).

Habitat of Rhacophorus dulongensis sp. nov. at the type locality in Dulongjiang Village, Yunnan Province, China. B, C. show the native bamboo species, Cephalostachyum virulentum, where the new species inhabits.
Photos by Ying-Chun Li.

Ping-Shin Lee, Ben Liu, Meng Ouyang, Ren-Da Ai, Xiao-Long Liu, Yan-Hong He, Ping-Qian Huang, Ying-Chun Li, R. S. Naveen, Zhi-Yong Yuan and Jin-Min Chen. 2024. Hidden in the Bamboo: A New Parachuting Frog (Rhacophoridae, Rhacophorus) from the borderlands of western China, with Comments on the Taxonomy of R. rhodopusZoosystematics and Evolution. 100(3): 851-862. DOI: 10.3897/zse.100.120224