Tuesday, April 7, 2020

[Herpetology • 2020] Leptobrachella suiyangensis • A New Species of Leptobrachella (Anura, Megophryidae) from Guizhou Province, China

 Leptobrachella suiyangensis
 Luo, Xiao, Gao & Zhou, 2020

Suiyang Leaf-litter Toad | 绥阳掌突蟾 ||  DOI: 10.3897/zookeys.923.47172

This study describes a new species of the genus Leptobrachella, Leptobrachella suiyangensis sp. nov. from the Huoqiuba Nature Reserve, Suiyang County, Guizhou Province, China, based on morphological data and phylogenetic analyses (16S rRNA mtDNA). The new species can be distinguished from other congeners by the molecular divergence and by a combination of morphological characters, including body size, dorsal and ventral patterns, dorsal skin texture, size of the pectoral and femoral glands, degree of webbing and fringing on the toes and fingers, dorsum coloration, and iris coloration in life. Currently, the genus Leptobrachella contains 75 species, 21 of which are found in China, including seven species reported from Guizhou Province. The uncorrected sequence divergence percentage between Leptobrachella suiyangensis sp. nov. and all homologous DNA sequences available for the 16S rRNA gene was found to be >4.7%. The new record of the species and its relationships with others in the same genus imply that species distribution, habitat variation, environmental adaptation, and diversity of the genus Leptobrachella in southwest China need to be further investigated.

Keywords: Leptobrachella suiyangensis sp. nov., mitochondrial DNA, morphology, Southwest China

Figure 3. Holotype of  Leptobrachella suiyangensis sp. nov. (GZNU20180606007) in life.
 A Dorsal view B Dorsolateral view C Ventral view D Right eye shown iris coloration E Volar view of the left hand F Plantar view of the left foot.

Leptobrachella suiyangensis sp. nov.

Diagnosis: The specimens were assigned to the genus Leptobrachella on the basis of the following characters: (1) small body size; (2) having an elevated inner metacarpal tubercle; (3) having macro-glands on body (including supra-axillary, femoral and ventrolateral glands); (4) lacking vomerine teeth; (5) having small tubercles on eyelids; (6) anterior tip of snout with whitish vertical bar (Dubois 1983; Matsui 1997, 2006; Lathrop et al. 1998; Delorme et al. 2006; Das et al. 2010). Leptobrachella suiyangensis sp. nov. can be distinguished from its congeners by referring to the following characters: (1) small body size (SVL 28.7–29.7 mm in males, 30.5–33.5 mm in females); (2) dorsal skin shagreened, with some of the granules forming longitudinal short skin ridges; (3) tympanum distinctly discernible, slightly concave, with a deep, black, supratympanic line; (4) ventrolateral glands are distinct, forming a dotted line; (5) dorsal surface shagreened and granular, lacking enlarged tubercles or warts, with some of the granules forming short longitudinal folds; (6) flanks with several distinct and large dark blotches; (7) ventral surface of throat grey-white, and surface of chest and belly yellowish creamy-white with marbled texture or with irregular light brown speckling; (8) supra-axillary, femoral, pectoral and ventrolateral glands are distinctly visible; (9) absence of webbing and lateral fringes on fingers, and toes feature rudimentary webbing and a weak lateral fringes; (10) relatively short hindlimbs (TIB/SVL ratio in males 0.46–0.47); (11) longitudinal ridges under the toes are interrupted at the articulations; (12) relative finger lengths I <II < IV < III, relative toe lengths I < II < V < III < IV; (13) dorsum greyish-brown, with small light-orange granules and distinct darker brown markings scattered with irregular light-orange pigmentation, and bicolored iris, coppery orange on the upper half and silver grey on the lower half.

Figure 5. Paratypes of  Leptobrachella suiyangensis sp. nov. in life.
 A GZNU20180606005, adult male (A), (B) GZNU20180606002, adult male C GZNU20180606003, adult female.

Etymology: The specific epithet “suiyangensis” refers to the name of the holotype locality, Taibai Town in Suiyang County of Guizohu Province, China. 
We suggest as its English name “Suiyang Leaf-litter Toad,” and its Chinese name as “Sui Yang Zhang Tu Chan (绥阳掌突蟾)”.

Distribution and habitats: Currently, Leptobrachella suiyangensis sp. nov. is known only from its holotype locality, Huoqiuba Nature Reserve, Suiyang County, Guizhou Province, China (Fig. 1). The specimens were collected in a stream (ca 1.5 m in width and ca 10 cm in depth) and from nearby well-preserved bamboo forests (1501 m a.s.l.). During June, males were calling from under bamboo leaves; others perch on or under rocks by the side of the stream.

 Tao Luo, Ning Xiao, Kai Gao and Jiang Zhou. 2020. A New Species of Leptobrachella (Anura, Megophryidae) from Guizhou Province, China. ZooKeys. 923: 115-140. DOI: 10.3897/zookeys.923.47172