Tuesday, June 4, 2019

[Herpetology • 2019] Gracixalus yunnanensis • A New Species of Gracixalus (Anura, Rhacophoridae) from Yunnan, China

Gracixalus yunnanensis
Yu, Hui, Wang, Rao, Wu & Yang, 2019

A new species of the genus GracixalusGracixalus yunnanensis sp. n., is described based on a series of specimens collected from southwestern and southern Yunnan, China. This species is distinguished from all other known congeners by a combination of the following characters: relatively small body size in adult males (SVL 26.0–34.2 mm); dorsal surface yellow brown or red brown; distinctive conical asperities on dorsum; males with an external subgular vocal sac and linea masculina; throat, chest, and belly nearly immaculate; venter surface orangish with yellow spots, semi-transparent; snout rounded; supratympanic fold distinct; iris bronze; lack of white patch on temporal region; tibiotarsal projection absent; sides of body nearly smooth with no black blotch; finger webbing rudimentary; and toe webbing formula I1.5–2II1.5–2.7III.5–3IV2.5–1.5V. Genetically, the new species diverges from its congeners by 2.2%–14.1% (uncorrected p-distance) and is closest to G. guangdongensis. However, the new species can morphologically be separated from G. guangdongensis by distinctive conical tubercles on dorsum (versus absent), lateral surface nearly smooth with no black blotches on ventrolateral region (versus lateral surface rough, scattered with tubercles and black blotches on ventrolateral region), snout rounded (versus triangularly pointed), iris bronze (versus iris brown), and ventral surface orangish (versus throat and chest creamy white and belly light brown).

Keywords: Gracixalus yunnanensis sp. n., taxonomy, Rhacophoridae, southwestern China

Figure 4. Dorsolateral (a) and ventral (b) views of the holotype of Gracixalus yunnanensis sp. n. in life and dorsal (c) and ventral (d) views of the holotype of Gracixalus yunnanensis sp. n. in preservative. Linea masculina is pointed by arrow.

Gracixalus yunnanensis sp. n. 

The new species is assigned to genus Gracixalus based upon molecular data and the following morphological characters: the presence of intercalary cartilage between terminal and penultimate phalanges of digits, tips of digits enlarged to discs bearing circummarginal grooves, vomerine teeth absent, inner (first and second) and outer (third and fourth) fingers non-opposable, and an inversed Y-shaped dark brown marking on dorsum (Fei 1999, Rowley et al. 2011, Chen et al. 2018). The new species is distinguished from its congeners by a combination of 1) SVL 26.0–34.2 mm in males; 2) dorsal surface yellow brown or red brown; 3) distinctive conical tubercles on dorsum; 4) males with an external subgular vocal sac; 5) throat granular; 6) finger webbing rudimentary; 7) linea masculina, a band of connective tissue between the rectus abdominus muscle and oblique abdominus muscle, present in males; 8) tibiotarsal articulation reaching eye; 9) snout rounded; 10) white patch absent on temporal region; 11) tibiotarsal projection absent; 12) supratympanic fold distinct; 13) ventral surface orangish, nearly immaculate, and semi-transparent; 14) nuptial pads present on finger I; 15) heels overlapping when legs at right angle to body; 16) iris bronze; and 17) body sides nearly smooth with no black blotch.

Figure 1. Map showing collection sites of Gracixalus yunnanensis sp. n. Star indicates the type locality (Xuelin) and circles indicate Fudong Township (1), Fazhanhe Township (2), Bada Township (3), Mt. Huanglian (4), Jinping (5), Lao Cai (6), Nghe An (7), and Houapan (8), respectively. Sequences of samples from sites 5–8 came from previous studies.

Distribution: In China, the new species is known from Yunnan (Lancang County, Menghai County, Lvchun County, and Jinping County). In addition, the new species also occurs in Laos (Houapan) and Vietnam (Lao Cai and Nghe An) because our molecular analyses revealed that samples from Houapan (KUHE 32453), Lao Cai (VNMN 4355, 4357, 4371), and Nghe An (AMS R173454) that were sequenced by previous studies also belong to the new species (Figs 2, 3). In Yunnan, specimens were found sitting on leaves of herbaceous plants (e.g., Amomum tsaoko and Eupatorium adenophorum). No eggs and tadpoles were found.

Etymology: The specific epithet yunnanensis refers to the distribution of this species in China, Yunnan Province.

 Guohua Yu, Hong Hui, Jian Wang, Dingqi Rao, Zhengjun Wu and Junxing Yang. 2019. A New Species of Gracixalus (Anura, Rhacophoridae) from Yunnan, China. ZooKeys. 851: 91-111. DOI: 10.3897/zookeys.851.32157

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