Leptobrachella shiwandashanensis, Chen & Peng & Pan & Liao & Liu & Huang, 2021

Chen, Weicai, Peng, Wanxiao, Pan, Weihu, Liao, Nanyan, Liu, Youjun & Huang, Yong, 2021, A new species of Leptobrachella Smith 1925 (Anura: Megophryidae) from Southern Guangxi, China, Zootaxa 5020 (3), pp. 581-596 : 588-592

Leptobrachella shiwandashanensis sp. nov.

Holotype. NNU202103250, adult male ( Figure 4A–E ), collected at Golden Camellia National Nature Reserve , Fangcheng City, Guangxi Province, China (21.462º N, 108.073º E; alt. 538 m), collected by Wei-Cai Chen on 10 April 2021.

Paratypes. NNUN202103213–15 , adult males and NNU202103146, adult female, collected at the same locality as holotype on 1 April 2021; NNU202103249–52, adult males, and NNU202103247, N202103248, adult females, collected at the same locality as holotype on 12 April 2021. NNU202103259–62, adult males, collected at SWDS National Nature Reserve , Shangsi County, Guangxi Province, China (21.544º N, 108.005º E; alt. 589 m). Wei-Cai Chen collected all specimens .

Etymology. The specific epithet ‘ shiwandashanensis ’ refers to the type locality, Mt. Shiwandashan. The suggested English name is Shiwandashan Leaf Litter Toad, and the Chinese name is Shi Wan Da Shan Zhang Tu Chan (十万k山AEẋDz).

Diagnosis. Leptobrachella shiwandashanensis sp. nov. can be distinguished from its congeners by a combination of the following characteristics: (1) small size (SVL 26.8–29.7 mm in males; 33.7–35.9 mm in females); (2) pale brown dorsal surfaces, with a brown inverse-triangle-shaped marking between the eyes; (3) creamy white ventral surface with brown spots on the lateral margin, with a near immaculate creamy white throat and chest; (4) absent webbing and lateral fringes on toes; (5) flanks with irregular black spots; (6) tibia-tarsal articulation reaching the posterior of the eye in males but reaching the shoulder in females; (7) heels that do not meet when the thighs are appressed at right angles to the body; (8) bicolored iris, with the upper half brownish-red, fading to silver in the lower half; and (9) a call consisting of a single note and a dominant frequency of 5.3–5.7 kHz (recorded at 23°C).

Description of holotype. Adult male, head wider than long (HW/HL=1.07); snout protruding, projecting slightly over the lower jaw; nostril oval-shaped, closer to the tip of snout than eye; canthus rostralis rounded; loreal region sloping and slightly concave; interorbital space flat; vertical pupil; eye diameter less the length of the snout (ED/ SNT=0.92); tympanum distinct and rounded, approximately half of eye diameter TD/ED=0.47; distinct, raised, grey supratympanic fold from the corner of the eye to supra-axillary gland; vomerine teeth absent; vocal sac openings located laterally on the floor of mouth; tongue with a shallow notch at the posterior tip ( Figure 4A–E ).

Tips of fingers slightly swollen; relative finger lengths I <II <IV <III; nuptial pad absent; subarticular tubercles absent; prominent inner palmar tubercle separated from the small outer palmar tubercle; finger webbing and dermal fringes absent. Tips of toes rounded, slightly swollen; relative toe lengths I <II <V <III <IV; subarticular tubercles absent, replaced by dermal ridges; pronounced large, oval inner metatarsal tubercle; outer metatarsal tubercle absent; toe webbing absent; lateral fringes absent. TIB/SVL=0.47; tibia-tarsal articulation reaching to posterior of the eye; heels not meeting when thighs appressed at right angles to the body.

Dorsal surface shagreened with small raised tubercles and ridges, more evident on the shoulder and dorsal surfaces of limbs; ventral surface creamy white with brown spots on lateral margin, near immaculate creamy white throat and chest; pectoral glands oval, approximately 1.4 mm in diameter; femoral glands oval, approximately 1.3 mm in diameter, located on the posteroventral surface of thighs, closer to the knee than to the vent; supra-axillary glands distinct and rounded, approximately 1.0 mm in diameter and interrupted ventrolateral glandular line distinct ( Figure 4A–E ).

Color of holotype in life. Pale brown dorsum with distinct brown, inverse-triangle-shaped marking between eyes; pale brown tympanum; brown supratympanic line from posterior corner of the eye to supra-axillary glands; posterior corner of eye creamy white; wide brown bars on upper lip; flanks with irregular black spots; distinct transverse dark-brown bars on the dorsal surface of forelimbs and hindlimbs; elbows, upper arms and tibiotarsal surfaces pale orange; ventral surface creamy white with brown spots on lateral margin; throat and chest near immaculate creamy white; pectoral and femoral glands creamy white, supra-axillary glands pale orange; pupil black; iris bicolored, upper half brownish-red, transitioning to silver in the lower half ( Figure 4A–E ).

Color of holotype in preservative. Dorsum and limbs surfaces faded to a uniform grey; brown, inverse-triangle-shaped marking distinctly visible between eyes; distinct small irregular black spots on flanks; throat, chest and belly creamy white; pectoral, femoral, supra-axillary and ventrolateral glands creamy white; dark bars on limbs, fingers and toes remained distinct; pale orange elbow; upper arm and tibiotarsus faded to grey.

Variation. Measurements of the type series are shown in Table 2 and Supplementary Table S2. Black spots on flanks are variable, ranging from four to seven spots. The color pattern of the dorsum is variable: specimens from SWDS are brown, whereas specimens from GC are pale brown. Ventrolateral glands form an interrupted or uninterrupted line.

Ecology and distribution. The new species was found in the evergreen forest at Mt. Shiwandashan between 300– 600 m. We found that males were calling near rocky streams about 2–3 m between 20:00–24:00 h. Although L. shiwandashanensis sp. nov. and L. shangsiensis occur in sympatry, the latter tends to call from rocks within or adjacent (about 1 m) to rocky streams with fast running currents.

Comparisons. We obtained comparative morphological data from the references (Supplementary Table S3, S4) and museum specimens (Supplementary Table S5). Leptobrachella shiwandashanensis sp. nov. differs from other Leptobrachella species based on morphological, genetic and acoustic data. Genetically, L. shiwandashanensis sp. nov. and other Leptobrachella species were separated by relatively large genetic distances (>7.0%) (Supplementary Table S1). Morphologically, L. shiwandashanensis sp. nov. can be distinguished from other Leptobrachella species based on the aforementioned diagnostic morphological characteristics (see Diagnosis).

By having supra-axillary and ventrolateral glands, L. shiwandashanensis sp. nov. differs from its congeners from South of the Isthmus of Kra, L. arayai , L. dringi , L. fritinniens , L. gracilis , L. hamidi , L. heteropus , L. kajangensis , L. kecil , L. marmorata , L. maura , L. melanoleuca , L. picta , L. platycephala , L. sabahmontana and L. sola (vs. absence in the latter species). By having a larger body size (SVL 26.8–29.7 mm in males, 33.7–35.9 mm in females), L. shiwandashanensis sp. nov. differs from L. baluensis (SVL 14.9–15.9 mm in males), L. bondangensis (SVL 17.8 mm in male), L. brevicrus (SVL 17.1–17.8 mm in males), L. fusca (SVL 16.3 mm in male), L. itiokai (SVL 15.2–16.7 mm in males), L. juliandringi (SVL 17.0– 17.2 mm in males), L. mjobergi (SVL 15.7–19.0 mm in males), L. natunae (SVL 17.6 mm in male), L. palmata (SVL 14.4–16.8 mm in males), L. parva (SVL 15.0– 16.9 mm in males) and L. serasanae (SVL 16.9 mm in female).

Leptobrachella shiwandashanensis sp. nov., L. shangsiensis and L. sungi occur in sympatry. However, L. shiwandashanensis sp. nov. differs from L. shangsiensis by the absence of toe webbing (vs. base of toes webbed) ( Figure 4F ); tibia-tarsal articulation reaching the posterior of the eye in males but reaching the shoulder in females (vs. tibia-tarsal articulation reaching the posterior of the eye in females); heels not meeting when thighs are appressed at right angles to body (vs. heels meeting when thighs are appressed at right angles to body); a call consisting of a single note and a dominant frequency of 5.3–5.7 kHz, and call durations 226.6 ms (vs. dominant frequency of 5.5–6.5 kHz, two types of calls, Type A call durations 64.8 ms and Type B call duration 277.1 ms) ( Figure 3 ). Leptobrachella shiwandashanensis sp. nov. differs from L. sungi by having a smaller body size (SVL 26.8–29.7 mm in males, 33.7–35.9 mm in females vs. SVL 48.3–52.7 mm in males, 58.9 mm in female); absence of toe webbing (vs. wide toe webbing); tympanum distinct (vs. tympanum indistinct); dorsal surfaces brown with a dark-brown, inverse-triangle-shaped marking between eyes (vs. dorsum uniformly light brown or with light spots).

Phylogenetically, L. shiwandashanensis sp. nov. is closely related to L. wuhuangmontis with a distinct genetic divergence (p =7.3%). Morphologically, L. shiwandashanensis sp. nov. differs from L. wuhuangmontis by having a brown dorsum with a dark-brown, inverse-triangle-shaped marking between eyes (vs. greyish purple dorsum with dark-brown markings, scattered orange-yellow blotches and white speckling), creamy white ventral surface with brown spots on lateral margins (vs. greyish white ventral surface mixed by tiny white and black dots), absence of toe webbing (vs. rudimentary toe webbing in L. wuhuangmontis ). Leptobrachella shiwandashanensis sp. nov. differs from L. aerea by having black spots on flanks and absent fringes on toes (vs. lacking black spots on flanks and wide fringes on toes). Leptobrachella shiwandashanensis sp. nov. differs from L. aspera by having a relatively larger body size (SVL 26.8–29.7 mm in males) and creamy white ventral surface with brown spots on lateral margin and near immaculate creamy white on throat and chest (vs. SVL 22.4 mm in male, creamy white with distinct dark patches on chest and abdomen). Leptobrachella shiwandashanensis sp. nov. differs from L. feii by having a relatively larger body size (SVL 26.8–29.7 mm in males, 33.7–35.9 mm in females) and creamy white ventral surface with brown spots on lateral margin and near immaculate creamy white on throat and chest (vs. SVL 21.5–22.8 mm in males, 25.7 mm in female; creamy white ventral surface with black blotches). Leptobrachella shiwandashanensis sp. nov. differs from L. minima by having absent toes webbing and creamy white ventral surface with brown spots on lateral margin and near immaculate creamy white on throat and chest (vs. rudimentary toe webbing and creamy white ventral surface). Leptobrachella shiwandashanensis sp. nov. differs from L. pelodytoides by lacking toe webbing (vs. wide toe webbing). Leptobrachella shiwandashanensis sp. nov. differs from L. ventripunctata by having a creamy white ventral surface with brown spots on lateral margin, near immaculate creamy white on throat and chest, and absence of toes webbing (vs. chest and belly with dark brown spots and rudimentary toe webbing).

For the remaining 52 known Leptobrachella species from North of the Isthmus of Kra, by having SVL 26.8– 29.7 mm in males, 33.7–35.9 mm in females, L. shiwandashanensis sp. nov. differs from the smaller L. applebyi (19.6–22.3 mm in males), L. ardens (21.3–24.7 mm in males), L. bashaensis (22.9–25.6 mm in males), L. bidoupensis (18.5–25.4 mm in males), L. crocea (22.2–27.3 mm in males), L. flaviglandulosa (23.0–27.0 mm in males), L. melica (19.5–22.7 mm in males), L. niveimontis (22.5–23.6 mm in males), L. pluvialis (21.3–22.3 mm in males), L. rowleyae (23.4–25.4 mm in males); from the larger L. nahangensis (40.8 mm in male) and L. zhangyapingi (45.8–52.5 mm in males).

Furthermore, lacking lateral fringes on toes differentiate L. shiwandashanensis sp. nov. from L. alpina , L. eos , L. firthi , L. isos , L. khasiorum , L. laui , L. liui , L. purpurus , L. tamdil , L. yingjiangensis , L. yunkaiensis and L. zhangyapingi (vs. wide lateral fringes on toes). In having black spots on flanks, L. shiwandashanensis sp. nov. differs from L. aerea , L. botsfordi , L. crocea , L. eos , L. firthi , L. isos , L. pallida , L. petrops and L. tuberosa (vs. absent). In lacking toe webbing, L. shiwandashanensis sp. nov. differs from L. tamdil (vs. wide toe webbing). The ventral color pattern of L. shiwandashanensis sp. nov. that is creamy white with brown spots on lateral margins and near immaculate creamy white on throat and chest distinguishes it from L. alpina (creamy white with dark spots), L. applebyi (reddish brown with white speckles), L. ardens (reddish brown with white speckles), L. bidoupensis (reddish brown with white speckles), L. bijie (white with distinct nebulous greyish speckles on chest and ventrolateral flanks), L. botsfordi (reddish brown with white speckles), L. crocea (bright orange), L. dorsospina (greyish white with black spots and orange pigmentations), L. flaviglandulosa (whitish with black speckling on margins), L. jinshaensis (cream white ventral surface of throat, and cream yellow chest and belly with purple speckling), L. kalonensis (pale, speckled brown), L. liui (creamy white with dark brown spots on chest and margins), L. macrops (greyish violet with white speckles), L. maculosa (brown with a few white speckles), L. mangshanensis (grey-white throat and creamy white belly, scattered with white speckles), L. maoershanensis (creamy white chest and belly with irregular black spots), L. melica (reddish brown with white speckles), L. niveimontis (marbling with black speckles), L. neangi (light purplish grey with dark brown mottling on throat), L. oshanensis (whitish with no markings or only small, light grey spots), L. pallida (reddish brown with white speckles), L. petrops (immaculate creamy white), L. pluvialis (dirty white with dark brown marbling), L. puhoatensis (reddish brown with white dusting), L. purpuraventra (greypurple with distinct nebulous greyish speckles on chest and ventrolateral flanks), L. pyrrhops (reddish brown with white speckles), L. rowleyae (pinkish milk-white to light brown chest and belly with numerous white speckles), L. suiyangensis (yellowish or creamy white with marbled patterning on chest and belly, or with irregular light brown speckles), L. tadungensis (reddish brown with white speckles), L. tengchongensis (white with dark brown blotches), L. wuhuangmontis (greyish white mixed with tiny white and black dots), L. yingjiangensis (creamy white with darkbrown flecks on chest and margins), and L. yunkaiensis (belly pink with distinct or indistinct speckles). In having dorsal skin rough with numerous tubercles, L. shiwandashanensis sp. nov. differs from L. applebyi , L. bidoupensis , L. kalonensis , L. melica , L. minima , L. nahangensis and L. tadungensis (vs. smooth).

By having higher dominant frequency (5.3–5.7 kHz, 23 °C) ( Figure 3 ), L. shiwandashanensis sp. nov. differs from L. applebyi (3.9–4.3 kHz, 21.5 °C), L. ardens (3.1–3.4 kHz, 23.6 °C), L. bidoupensis (1.9–2.3 kHz, 19.9 °C), L. botsfordi (2.6–3.2 kHz, 14 °C), L. crocea (2.6–3.0 kHz, 21.6–25.1 °C), L. fuliginosa (2.3–2.4 kHz, 19.3–19.6 °C), L. heteropus (2.8 kHz, 21 °C), L. jinshaensis (4.5–4.6 kHz, 20 °C), L. maculosa (2.7 kHz, 23.3–24.1 °C), L. melanoleuca (3.1–3.3 kHz, 23.9 °C), L. melica (2.9–3.8 kHz, 26.1 °C), L. pallida (2.4–2.7 kHz, 18.9 °C), L. pyrrhops (1.9–22 kHz, 25 °C), L. rowleyae (2.6–3.0 kHz, 21.6–25.1 °C), L. sola (3.1–3.2 kHz, 24.2–24.3 °C), L. tadungensis (2.6–3.1 kHz, 12.9–22.3 °C), L. tuberosa (2.6–2.8 kHz, 22.5–24.5 °C) and L. yeae (4.8 kHz, 15–22 °C). Whereas L. shiwandashanensis sp. nov. has a lower dominant frequency (5.3–5.7 kHz, 23 °C) compared with L. aerea (6.2–6.4 kHz, 22.4 °C), L. chishuiensis (6.1–6.3 kHz, 20 °C), L. isos (7.83–8.55 kHz, 26.4 °C), L. marmorata (6.0–6.2 kHz, 22.8 °C), L. pelodytoides (6.4–6.6 kHz, 22.7 °C), L. shangsiensis (5.5–6.5 kHz, 21.5°C), L. ventripunctata (6.1–6.4 kHz, 15 °C) and L. yingjiangensis (5.7–5.9 kHz, 19 °C).

Figures

FIGURE 3. Advertisement calls of Leptobrachella shiwandashanensis sp. nov. and L. shangsiensis.

FIGURE 4. A–E: Leptobrachella shiwandashanensis sp. nov. (Holotype). A: dorsal view, B: ventral view, C: lateral view, D: ventral view of the foot, E: ventral view of the hand. F: ventral view of the foot of L. shangsiensis (NNU202103076).