Monday, July 8, 2019

[Herpetology • 2019] Nidirana leishanensis • A New Species of the Asian Music Frog Genus Nidirana (Anura, Ranidae) from Southwestern China


Nidirana leishanensis
Li, Wei, Xu, Cui, Fei, Jiang, Liu & Wang, ​2019


Abstract 
The Asian music frog genus Nidirana is widely distributed in East and Southeastern Asia. Systematic profiles of the group remain on debate, and cryptic species are expected especially in the species with wide distributional range. Here, we describe a new species of the genus from Southwestern China. Phylogenetic analyses based on mitochondrial DNA and nuclear DNA supported the new species as an independent clade nested into the Nidirana clade and sister to N. hainanensis. Morphologically, the new species could be distinguished from its congeners by a combination of the following characters: a large body size in males (SVL > 49 mm); the presence of lateroventral grooves both on fingers and toes; relative finger lengths: II < IV < I < III; tibiotarsal articulation reaching the level between eye and nostril when leg stretched forward; a pair of subgular internal vocal sacs at corners of throat in males; nuptial pad present on the inner side of base of fingers I and II in males in breading season; webbing formula: I 2 –21/3 II 2 –22/3 III 31/2 –32/3 IV 32/3 –3V. The findings provided a better knowledge on phylogenetic assignments of the genus Nidirana, and indicated future deeper investigations necessarily for exploring systematic settings of the group.

Figure 1: Sampling localities in this study. Localities 1–5 were all in China: 1, Emei Mountain, Sichuan Province (Prov.); 2, Jiangcheng County (Co.), Yunnan Prov.; 3, Leigong Mountain, Leishan Co., Guizhou Prov.; 4, Diaoluo Mountain, Lingshui Co., Hainan Prov.; 5, Wuyi Mountain, Fujian Prov. Different species were denoted as different colors. Sample numbers (for information see Table 1) were labeled beside localities.

Figure 7: Photos of the holotype CIBLS20170727002 of Nidirana leishanensis sp. nov. in life.
 (A) Dorsal view. (B) Ventral view. (C) Ventral view of hand. (D) Ventral view of foot. (E) Nuptial pads on the first and second fingers. (F) Lateral view showing subgular external vocal sac. 1, nuptial pad on inner side of base of fingers I and II; 2, a pair of subgular internal vocal sac at corners of throat; 3, suprabrachial gland. Photographed by Shize Li.

Nidirana leishanensis sp. nov.

Diagnosis: 
Nidirana leishanensis sp. nov. is assigned to the genus Nidirana based on molecular data and the following morphological characters: disks of digits dilated, pointed; lateroventral grooves present on digits; feet full webbed or half webbed; dorsolateral folds distinct; the presence of large suprabrachial gland in males; nuptial pad present at the base of first finger in males; vocal sacs present in males.

Nidirana leishanensis sp. nov. could be distinguished from its congeners by a combination of the following characters: (1) a large body size in males (SVL > 49 mm); (2) the presence of lateroventral grooves both on fingers and toes; (3) relative finger lengths: II < IV < I < III; (4) tibiotarsal articulation reaching to the level between eye and nostril when leg stretched forward; (5) a pair of subgular internal vocal sacs at corners of throat present in males; (6) the presense of nuptial pad on the inner side of base of fingers I and II in males; (7) webbing formula: I 2 –2 13/ II 2 –2 2/3 III 3 1/2 –3 2/3 IV 3 2/3 –3V.




Figure 8: Color variations in Nidirana leishanensis sp. nov. in life.
 (A), (B) and (C) dorsolateral view of the male specimens CIBLS20150628001, CIBLS20150628005 and CIBLS20150628007, respectively. (D) and (E) dorsolateral view of the female specimens CIBLS20150627002 and CIBLS20150627003, respectively. (F) ventral view of the female specimen CIBLS20150627002. Photographed by Shize Li.

Figure 11: Habitats of Nidirana leishanensis sp. nov. in the type locality, Leigong Mountain, Leishan County, Guizhou Province, China.
(A) Landscape. (B) A paddy field with a Nidirana leishanensis sp. nov. in the water (insert). (C) A frog eating a small mollusk for food. (D) A tadpole swimming in the paddy field. Photographed by Shize Li.

Ecology: Nidirana leishanensis sp. nov. is currently known only from Leigong Mountain (26.25°N–26.53°N, 108.08°E–108.41°E) in Leishan County, Guizhou Province, China (Fig. 1). Nidirana leishanensis sp. nov. inhabited the paddy field or nearby the artificial trench where the water flows very slowly (Fig. 11A), at elevations from 650 to 1,300 m a. s. l., and the individuals could be found on the ridge of paddy field or in the paddy field (Figs. 11A–11C). The tadpoles of the species could be found in the water of ponding in the paddy (Fig. 11D). The species could eat some small mollusks for food (Fig. 11C). Two sympatric amphibian species, Microhyla fissipes (Boulenger, 1884) and Polypedates megacephalus (Hallowell, 1861 “1860”) were found in the type locality.

Etymology: This specific epithet “leishanensis” is a Latinize toponymic adjective that refers to Leigong Mountains, Leishan County, Guizhou Province, China, where the new species was collected. For the common name, we suggest Leishan Music Frog (English) and Lei Shan Qin Wa (Chinese).


Conclusion: 
We described a new species of the Asian music frog genus Nidirana (Amphibia, Anura, Ranidae) from Southwestern China, and confirmed its phylogenetic placements. Nidirana leishanensis sp. nov. is currently only known from Leigong Mountain, Guizhou Province of China, and inhabits still waters in the mountains at mid and low elevations similar to most music frogs. Although there were still a mass of unresolved systematic assignments and assumed underestimated diversity in the genus Nidirana, the findings here give a better knowledge on species diversity and phylogenetic assignments of the group. Future works are expected mainly on re-examination of the doubtful classifications of proposed-misidentified populations using credible molecular phylogenetic approaches and painstaking field surveys especially in the poorly investigated regions that harboring high species richness.



Shize Li, Gang Wei, Ning Xu, Jianguo Cui, Liang Fei, Jianping Jiang, Jing Liu and Bin Wang. ​2019. A New Species of the Asian Music Frog Genus Nidirana (Amphibia, Anura, Ranidae) from Southwestern China. PeerJ. 7:e7157.  DOI: 10.7717/peerj.7157