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| Leptobrachella niveimontis Chen, Poyarkov, Yuan & Che
Mt. Daxue Leaf Litter Toad | 雪山掌突蟾
in Chen, Xu, Poyarkov, Wang, ... et Che, 2020.
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Abstract
Asian leaf-litter toads of the genus Leptobrachella represent a great anuran diversification in Asia. Previous studies have suggested that the diversity of this genus is still underestimated. During herpetological surveys from 2013 to 2018, a series of Leptobrachella specimens were collected from the international border areas in the southern and western parts of Yunnan Province, China. Subsequent analyses based on morphological and molecular data revealed three distinct and previously unknown lineages, which we formally describe as three new species herein. Among them, we describe a new species that occurs at the highest known elevation for Leptobrachella in China. Four species of Leptobrachella, including two new species, are found in the same reserve. Furthermore, our results suggest that the population from Longchuan County, Yunnan, may represent an additional new species of Leptobrachella, although we tentatively assigned it to Leptobrachella cf. yingjiangensis due to the small sample size examined. Lastly, we provide the first description of females of L. yingjiangensis. Our results further highlight that both micro-endemism and sympatric distributions of species are common patterns in Leptobrachella, that contribute to taxonomic and conservation challenges in these frogs. We provide an identification key for Leptobrachella known to occur in Yunnan. Given the lack of knowledge on species diversity of Leptobrachella along international border areas, we recommend that future studies include trans-boundary collaborative surveys.
Keywords: Biodiversity hotspot, Conservation, Cryptic diversity, Micro-endemism, National border, Speciation, Taxonomy
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| Figure 1. Sampling localities of Leptobrachella used in this study A: Jinzhuzhai Village, Yingjiang, Yunnan, China; B: Gongdong, Longchuan, Yunnan, China; C: Daxueshan Nature Reserve, Lincang, Yunnan, China; D: Daweishan, Pingbian, Yunnan, China; E: Xiaoqiaogou Nature Reserve, Wenshan, Yunnan, China. |
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| Figure 2. Bayesian phylogram of Leptobrachella inferred from 16S mtDNA gene fragments “*” denotes high support by Bayesian posterior probabilities (BPP>0.95) and bootstrap support values (BS>70%); “-” represents low support values. Scale bar represents 0.1 nucleotide substitutions per site. Outgroup taxa not shown. Photos showing species of Leptobrachella newly collected from Yunnan. Numbers in brackets after species names correspond to Samples IDs in Supplementary Table S1. |
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| Figure 3. Holotype of Leptobrachella niveimontis sp. nov. (KIZ028277) in life A: Dorsolateral view; B: Ventral view; C: Left hand in dorsal view; D: Left foot in dorsal view; E: Lateral view; F: Cloacal area view. |
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| Figure 5. Paratypes of Leptobrachella niveimontis sp. nov. in life A: KIZ015734; B: KIZ015743. |
Leptobrachella niveimontis sp. nov. Chen, Poyarkov, Yuan & Che
Diagnosis: Leptobrachella niveimontis sp. nov. can be distinguished from its congeners by the following combination of morphological characters: (1) body size small (SVL 22.5–23.6 mm in four adult males, 28.5–28.7 mm in two females); (2) tympanum distinct, upper half black; (3) skin on dorsum scattered with fine reddish tubercles; (4) ventral sides marbled with distinct irregular black speckling on bluish-white background; (5) black blotches distinct, scattered on dorsum and flanks; (6) ventrolateral glands distinct, forming continuous white line; (7) finger webbing and fringes absent; (8) toe webbing rudimentary, toe lateral fringes narrow; (9) longitudinal ridges distinct under toes; (10) supratympanic ridges distinct, with reddish-brown pigmentation; (11) numerous rounded whitish speckles present on cloacal region; (12) pectoral gland white, larger than femoral gland; (13) iris distinctly bicolored, typically bright orange red in upper half, fading to silver white in lower half.
Etymology: The specific epithet “niveimontis” is a toponymic adjective derived from the Latin words “niveus” for “snowy”, and “montanus” meaning “related to mountains”, given in reference to the type locality of the new species, Mt. Daxue (literally “Great Snowy Mountain”) of Yunnan Province, China, and also in reference to the ecology of the new species, inhabiting high elevations in low temperature climate zones.
For the common name, we recommend “Mt. Daxue Leaf Litter Toad” (English) and “Xue Shan Zhang Tu Chan” (雪山掌突蟾) (Chinese).
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| Figure 6. Breeding habitat of Leptobrachella niveimontis sp. nov. near Wumulong Ganhe Protection Station, Daxueshan Nature Reserve, Yunnan Province, China. |
Distribution and habits: Leptobrachella niveimontis sp. nov. is presently known only from its type locality, near Wumulong Ganhe Protection Station of Daxueshan Nature Reserve in Yongde County, Lincang, Yunnan Province, China. The new species was found along small creeks or rocky streams in well-preserved montane evergreen broadleaf forest at elevations between 2 569 m and 2 601 m a.s.l. (Figure 6). Leptobrachella niveimontis sp. nov. is the fifth known species of the genus inhabiting elevations above 2 000 m, and to the best of our knowledge it also occurs at the highest elevation as compared to other Chinese species of Leptobrachella. During our field surveys, calling males were recorded mostly inside the rocky crevices, and some were found hiding under leaf litter. Ubiquitous orthopteran-like calls could be heard along the stream from April to May, and very few calls were detected during July. The gravid female collected in April carried pure white eggs.
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| Figure 7. Holotype of Leptobrachella flaviglandulosa sp. nov. (KIZ032626) in life A: Dorsolateral view; B: Ventral view; C: Dorsal view; D: Lateral view; E: Hand in ventral view; F: Foot in ventral view; G: Iris coloration; H: Dorsal view of thighs; L: Posteroventral view of thigh. |
Leptobrachella flaviglandulosa sp. nov. Chen, Wang & Che
Diagnosis: Leptobrachella flaviglandulosa sp. nov. can be distinguished from its congeners by the following combination of morphological characters: (1) body size small (SVL 22.99–26.97 mm in 13 adult males, 29.30 mm in single adult female); (2) tympanum distinct, partially covered by black marking; (3) black supratympanic line present; (4) skin on dorsum shagreened with fine yellowish-brown tubercles; (5) venter whitish with small black speckling on throat, chest and belly margins; (6) supra-axillary gland, femoral, pectoral and ventrolateral glands yellowish; (7) ventrolateral glands forming a discontinuous line; (8) finger webbing and fringes absent; (9) toe webbing poorly developed and lateral fringes narrow; (10) longitudinal ridges distinct under toes and interrupted at the articulations; (11) distinct black blotches scattered on dorsum and flanks; (12) “\ /”-shaped yellow markings on dorsum in scapular region; (13) pectoral glands larger than femoral glands; (14) iris distinctly bicolored, typically golden-orange in upper half, fading to whitish grey in lower half.
Etymology: The species epithet, “flaviglandulosa”, is a Latin adjective in feminine gender, derived from Latin “flavus” for “yellow color” and “glandula” for “gland”, in reference to characteristic life coloration of femoral, pectoral and ventrolateral glands in the new species.
For the common name, we recommend “Yellow-gland Leaf Litter Toad” (English) and “Huang Xian Zhang Tu Chan” (黄腺掌突蟾) (Chinese).
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| Figure 9. Breeding habitat and general aspect in field of Leptobrachella spp. in Xiaoqiaogou Nature Reserve A1: Breeding stream in Fadou Station, which harbors three co-occurring species: Leptobrachella bourreti, L. flaviglandulosa sp. nov., and L. nyx. A2: Stream in Nanchang Station, which harbors two co-occurring sympatric species: Leptobrachella flaviglandulosa sp. nov. and L. nyx. A3: Stream in Xiaoqiaogou Station, which harbors two sympatric species: L. bourreti and Leptobrachella feii sp. nov. B1: Leptobrachella bourreti in the field. B2: Leptobrachella flaviglandulosa sp. nov. in the field. B3: Leptobrachella feii sp. nov in the field. |
Distribution and habits: Leptobrachella flaviglandulosa sp. nov. is currently known only from Xiaoqiaogou Nature Reserve, Xichou County, Wenshan City, Yunnan Province, China. The species was found in the environs of the Fadou, Shangchang and Nanchang stations of the nature reserve. The new species was recorded along small seeps or clear-water rocky mountain streams in well-preserved montane evergreen broadleaf forest at elevations between 1000 and 1400 m a.s.l. (Figure 9). The new species was recorded in sympatry with L. bourreti and L. nyx. During our field surveys, calling males were found mostly while sitting on vegetation, and some were calling from rocky crevices. An insect-like calls could be heard along the stream from March to June; gravid female was collected in March bearing pure-white eggs.
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| Figure 10. Holotype of Leptobrachella feii sp. nov. (KIZ032625) in life A: Dorsolateral view; B: Ventral view; C: Dorsal view; D: Lateral view; E: Hand in ventral view; F: Foot in ventral view; G: Iris coloration; H: Dorsal view of thighs; L: Posteroventral view of thigh. |
Leptobrachella feii sp. nov. Chen, Yuan & Che
Diagnosis: Leptobrachella feii sp. nov. can be distinguished from its congeners by a combination of the following morphological characters: (1) body size small (SVL 21.51–22.75 mm in 5 adult males, 25.67 mm in a single adult female); (2) tympanum distinct, partially covered by black marking; (3) distinct black supratympanic line; (4) skin on dorsum shagreened with small tubercles and unequal dermal ridges; (5) distinct black blotches scattered on the creamy white chest and belly; (6) small black spots densely covering the throat; (7) ventrolateral glands present, forming a distinct continuous white line; (8) finger webbing and fringing absent; (9) toe webbing rudimentary with narrow lateral fringes; (10) longitudinal ridges under toes distinct and uninterrupted at the articulations; (11) small white pectoral glands; (12) black patches scattered on lateral sides of the body; (13) relatively long head (HDL/SVL=0.38–0.43 in males); and (14) iris distinctly bicolored, typically golden orange in upper half, fading to silver white in lower half.
Etymology: The specific epithet “feii” is a patronymic noun in the genitive singular; derived from the name of Prof. Liang Fei of the Chengdu Institute of Biology, CAS, China, in recognition of his long-term and significant contribution to the advancement of amphibian research in China, particularly his research on the family Megophryidae.
For the common name, we recommend “Fei's Leaf Litter Toad” (English) and “Fei Shi Zhang Tu Chan” (费氏掌突蟾) (Chinese).
Distribution and habits: Leptobrachella feii sp. nov. is currently known to occur at two disjunct localities: Xiaoqiaogou Nature Reserve, Xichou County, Wenshan City, Yunnan Province, China, and Daweishan Nature Reserve, Pingbian County, Yunnan Province, China (Figure 1); these two sites are separated by a flying distance about 150 km. The new species was found along small seeps in well-preserved montane evergreen broadleaf forest at elevations between 1 577 m and 1 850 m a.s.l. (Figure 9). The new species is sympatric with L. bourreti. During our field surveys, males were usually recorded while calling sitting on vegetation (usually on the members of the family Acanthaceae species; see Figure 9). Advertisement calls of the new species, resembling calling of orthopterans, could be heard along the streams from March to June; gravid female collected in April was swollen with pure white eggs.
Jin-Min Chen, Kai Xu, Nikolay A. Poyarkov, Kai Wang, Zhi-Yong Yuan, Mian Hou, Chatmongkon Suwannapoom, Jian Wang and Jing Che. 2020. How Little is Known about “the Little Brown Frogs”: Description of Three New Species of the Genus Leptobrachella (Anura: Megophryidae) from Yunnan Province, China. Zoological Research. DOI: 10.24272/j.issn.2095-8137.2020.036
