Leptobrachella jinshaensis, Cheng & Shi & Li & Liu & Li & Wang, 2021

Cheng, Yan-Lin, Shi, Sheng-Chao, Li, Jiaqi, Liu, Jing, Li, Shi-Ze & Wang, Bin, 2021, A new species of the Asian leaf litter toad genus Leptobrachella Smith, 1925 (Anura, Megophryidae) from northwest Guizhou Province, China, ZooKeys 1021, pp. 81-107 : 81

Leptobrachella jinshaensis sp. nov. Figs 3 , 4 , 5 , 6 ; Tables 1, 2, 4, Suppl. material 1: Table S1, Suppl. material 2: Table S2

Holotype.

CIBJS20200516004 , adult male (Figs 4 , 5 ), collected from Lengshuihe Nature Reserve , Jinsha County (27.536944°N, 105.999166°E, ca. 770 m a. s. l.), Guizhou Province, China by Shi-Ze Li on 16 May 2020.

Paratypes.

Four adult males from the same place as holotype. Two adult males CIBJS20200516001 and CIBJS20200516002 collected by Shi-Ze LI, and two adult males CIBJS20200516003 and CIBJS20200516005 collected by Jing LIU, all of them were collected on 16 May 2020 .

Diagnosis.

Leptobrachella jinshaensis sp. nov. is assigned to the genus Leptobrachella based on molecular phylogenetic analyses and the following morphological characters: medium size, rounded finger tips, the presence of an elevated inner palmar tubercle not continuous to the thumb, the presence of macroglands on body (including supra-axillary, pectoral, and femoral glands), vomerine teeth absent, tubercles on eyelids, and the anterior tip of snout with a vertical white bar.

Leptobrachella jinshaensis sp. nov. can be distinguished from its congeners by a combination of the following characters: body of medium size ( SVL 29.7-31.2 mm in five adult males); dorsal skin shagreened, some of the granules forming longitudinal short skin ridges; tympanum distinctly discernible, slightly concave; supra-axillary, femoral, pectoral, and ventrolateral glands distinctly visible; absence of webbing and lateral fringes on fingers; toes with narrow lateral fringes and without webbing; heels overlapping when thighs positioned at right angles to the body; tibia-tarsal articulation reaching the middle eye when leg stretched forward.

Description of holotype

(Figs 4 , 5 ). Adult male. SVL in 31.1 mm. Head length slightly longer than head width ( HDL /HDW 1.02); snout slightly protruding, projecting slightly beyond margin of the lower jaw; nostril closer to snout than eye; canthus rostralis gently rounded; loreal region slightly concave; interorbital space flat, interorbital distance slightly longer than internarial distance; pineal ocellus absent; vertical pupil; eye diameter slightly shorter than snout length; tympanum distinct, rounded, and slightly concave, diameter smaller than that of the eye ( TMP /ED 0.61); upper margin of tympanum in contact with supratympanic ridge; vomerine teeth absent; tongue notched behind; supratympanic ridge distinct, extending from posterior corner of eye to supra-axillary gland.

Forelimbs slender, 48.9% of snout-vent length; tips of fingers rounded, slightly swollen; relative finger lengths I < II <= IV < III; absence of webbing; nuptial pad and subarticular tubercles absent; inner palmar tubercle large, rounded separated from the smaller, round outer palmar tubercle.

Hindlimbs slender, tibia slightly longer than thigh length and 48.4% of snout-vent length; heels overlapping when thighs are positioned at right angles to the body, tibiotarsal articulation reaching middle eye when leg stretched forward; relative toe lengths I < II < V < III < IV; tips of toes round, slightly dilated; subarticular tubercle at the articulations of the toes absent; toes without webbing; lateral fringes narrow on all toes; inner metatarsal tubercle present, large, oval, outer metatarsal tubercle absent.

Dorsal surface shagreened and granular, some of the granules forming short longitudinal folds dorsally on the flank; ventral skin smooth; dense tiny granules present on ventral surface of thigh and tibia; pectoral gland and femoral gland white, oval, distinctly visible. Ventrolateral gland distinctly visible and forming an incomplete line.

Colouration of holotype in life.

Dorsum brown, with small, distinct darker brown markings and spots, and irregularly dispersed light orange speckles. A dark brown inverted triangular pattern between anterior corners of eyes. Tympanum brown, a dark brown bar above tympanum, and a dark brown bar under the eye, distinct black supratympanic line present; transverse dark brown bars on dorsal surface of limbs; distinct dark brown blotches on flanks from groin to axilla, longitudinally in two rows; elbow and upper arms with dark bars and distinct coppery orange colouration; fingers and toes with distinct dark bars. Ventral surface of throat cream white, chest, and belly cream yellow with purple speckling, and on flanks presence of distinct nebulous greyish speckling; ventral surface of limbs grey purple. Supra-axillary gland, femoral, pectoral, and ventrolateral glands white (Fig. 5 ).

Colouration of holotype in preservation.

Dorsum of body and limbs fade to brown copper; transverse bars on limbs become more distinct. Ventral surface of body and limbs fade to cream white. Supra-axillary, femoral, and pectoral glands fade to creamy yellow (Fig. 4 ).

Variation.

Measurements of adult specimens were presented in Tables 2 and 4 . All specimens were similar but some individuals different from the holotype in colour pattern. In CIBJS 20200516002, the tympana are dark brown (Fig. 6A ); in CIBJS 20200516005, the dorsum is olive grey (Fig. 6B ) and the pectoral glands on the left side not obviously (Fig. 6D ); in CIBJS 20200516003 ventrolateral glands scattered and unlined (Fig. 6C ).

Advertisement call.

In total, 109 advertisement calls of Leptobrachella jinshaensis sp. nov. were recorded in Lengshuihe Nature Reserve, Jinsa County, Guizhou Province, China on 16 May 2020 between 21:00-22:00. The call description is based on recordings of the holotype CIBJS 20200516004 under a stone nearby a stream, and the ambient air temperature was 20 °C. The sonograms and waveforms of the new species are shown in Fig. 7 and Suppl. material 2: Table S2. The call has two kinds of notes, and each call contains two or three notes (mean 2.12 ± 0.33, n = 109). Call duration was 117-156 ms (mean 132.7 ± 8.6, n = 109). Call interval was 62-106 ms (mean 84.3 ± 10.4, n = 108), and each consists of two types of note. The first type of note is the start note in each call and beginning with lowest energy pulses, then increasing to the peak; in the second type, the amplitude begins with highest pulses and then decreasing towards the end of each note. The duration of first type of note with 35-71 ms (mean 48.77 ± 7.90, n = 109), the duration of the second type of note with 39-78 ms (mean 52.93 ± 8.85, n = 122), the duration between notes 18-40 ms (mean 23 ± 5.68, n = 122). The dominant frequency of calls is 4500-4688 Hz (mean 4525 ± 0.065 Hz).

Secondary sexual characteristics.

Adult males with a comparatively large single subgular vocal sac and nuptial pads and spines absent.

Comparisons.

Measurements were given in mm. In male, by body size moderate in male ( SVL 29.7-31.2, n = 5), Leptobrachella jinshaensis sp. nov. is larger than L. aerea (25.1-28.9), L. alpina (24.0-26.4), L. applebyi (19.6-22.3), L. ardens (21.3-24.7), L. baluensis (14.9-15.9), L. bidoupensis (18.5-25.4), L. bondangensis (17.8), L. brevicrus (17.1-17.8), L. crocea (22.2-27.3), L. feii (21.5-22.8), L. flaviglandulosa (23.0-27.0), L. fusca (16.3), L. isos (23.7-27.9), L. itiokai (15.2-16.7), L. juliandringi (17.0-17.2), L. khasiorum (24.5-27.3), L. laui (24.8-26.7), L. maculosa (24.2-26.6), L. mangshanensis (22.22-27.76), L. maura (26.1), L. melica (19.5-22.8), L. mjobergi (15.7-19.0), L. natunae (17.6), L. niveimontis (22.5-23.6), L. parva (15.0-16.9), L. palmata (14.4-16.8), L. pallida (24.5-27.7), L. petrops (23.6-27.6), L. pluvialis (21.3-22.3), L. purpurus (25.0-27.5), L. rowleyae (23.4-25.4), L. serasanae (16.9), L. tengchongensis (23.9-26.0), L. ventripunctata (25.5-28.0), and L. yingjiangensis (25.7-27.6); and smaller than L. eos (33.1-34.7), L. gracilis (34.3-39.0), L. marmorata (32.3-38.0), L. nahangensis (40.8), L. platycephala (35.1), L. sungi (48.3-52.7), L. tamdil (32.0), and L. zhangyapingi (45.8-52.5).

By the presence of supra-axillary and ventrolateral glands, Leptobrachella jinshaensis sp. nov. can be easily distinguished from L. arayai , L. dringi , L. fritinniens , L. gracilis , L. hamidi , L. heteropus , L. kajangensis , L. kecil , L. marmorata , L. melanoleuca , L. maura , L. picta , L. platycephala , L. sabahmontana , and L. sola (vs. lacking supra-axillary and ventrolateral glands in the latter).

By tympanum distinctly visible, Leptobrachella jinshaensis sp. nov. differs from L. crocea and L. tuberosa (vs. invisible in the latter).

By having black spots on flanks, Leptobrachella jinshaensis sp. nov. differs from L. aerea , L. botsfordi , L. firthi , L. crocea , L. isos , L. pallida , L. petrops , and L. tuberosa (vs. lacking in the latter).

By toes without webbing, Leptobrachella jinshaensis sp. nov. differs from L. aerea , L. alpina , L. applebyi , L. bidoupensis , L. bijie , L. botsfordi , L. bourreti , L. chishuiensis , L. crocea , L. eos , L. feii , L. firthi , L. fuliginosa , L. isos , L. khasiorum , L. lateralis , L. laui , L. liui , L. macrops , L. mangshanensis , L. maoershanensis , L. marmorata , L. melica , L. minima , L. nahangensis , L Leptobrachella namdongensis , L. niveimontis , L. nokrekensis , L. nyx , L. pluvialis , L. pluvialis , L. puhoatensis , L. purpurus , L. purpuraventra , L. pyrrhops , L. sabahmontaus , L. shangsiensis , L. suiyangensis , L. tengchongensis , L. tuberosa , L. ventripunctata , L. wuhuangmontis , L. yingjiangensis , L. yunkaiensis , and L. zhangyapingi (vs. webbing rudimentary in the latter); and differs from L. flaviglandulosa and L. pelodytoides (vs. webbing present in the latter).

By toes with narrow lateral fringes, Leptobrachella jinshaensis sp. nov. differs from L. aerea , L Leptobrachella alpina , L. firthi , L. laui , L. liui , L. khasiorum , and L. yunkaiensis (vs. wide in the latter); and differs from L. kalonensis , L. macrops , L. minima , L. marmorata , L. namdongensis , L. nyx , L. oshanensis , L. pyrrhops , L. rowleyae , and L. tuberosa (vs. lacking in the latter).

By dorsal surface shagreened and granular, lacking enlarge tubercles or warts, Leptobrachella jinshaensis sp. nov. differs from L. applebyi , L. bidoupensis , L. kalonensis , L. melica , L. minima , L. nahangensis , L. shangsiensis , and L. tadungensis (all of which have the dorsum smooth), and L. bourreti (dorsum smooth with small warts), L. fuliginosa (dorsum smooth with fine tubercles), L. liui (dorsum with round tubercles), L. macrops (dorsum roughly granular with large tubercles), L. maoershanensis (dorsum shagreened with tubercles), L. minima (dorsum smooth), L. nyx (dorsum with round tubercles), L. nokrekensis (dorsum tubercles and longitudinal folds), L. pelodytoides (dorsum with small, smooth warts), L. tamdil (dorsum weakly tuberculate, with low, oval tubercles), L. tuberosa (dorsum very tuberculate), L. yunkaiensis (dorsum with raised warts), and L. wuhuangmontis (dorsum rough with conical tubercles).

By having higher dominant frequency (4.5-4.7 kHz, 20 °C), Leptobrachella jinshaensis 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. 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) and L. tuberosa (2.6-2.8 kHz, 22.5-24.5 °C). The call of the new species appears to have lower frequency compared to the calls attributed to L. aerea (6.2-6.4 kHz, 22.4 °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. ventripunctata (6.1-6.4 kHz, 15 °C) and L. yingjiangensis (5.7-5.9 kHz, 19 °C).

By call duration 117-156 ms, Leptobrachella jinshaensis sp. nov. differs from L. aerea (16-28 ms), L. bidoupensis (308-400), L. botsfordi (239-303 ms), L. firthi (18-24 ms), L. fuliginosa (51-80 ms), L. isos (31-38 ms), L. maculosa (889-907 ms), L. marmorata (1900-6700 ms), L. melanoleuca (40-63 ms), L. pallida (627-729 ms), L. petrops (44-57 ms), L. puhoatensis 6-14 ms, L. shangsiensis (64-69 ms), L. tadungensis (248-353 ms) and L. yingjiangensis (28-42 ms).

Seven species ( L. liui , L. oshanensis , L. purpuraventra , L. bijie , L. suiyangensis , L. chishuiensis , and L. ventripunctata ) of the genus occur in Guizhou Province, China ( Fei et al. 2012; Wang et al. 2019; Luo et al. 2020; Li et al. 2020a). The new species differs from L. liui by having narrow lateral fringes on toes (vs. wide in the latter), dorsal surface shagreened with small granules, and lacking enlarge tubercles or warts (vs. dorsum with round tubercles in the latter); differs from L. oshanensis by having narrow lateral fringes on toes (vs. lacking in the latter); differs from L. purpuraventra and L. suiyangensis by heels overlapping when thighs are positioned at right angles to the body (vs. just meeting in the latter); differs from L. purpuraventra by tibia-tarsal articulation reaches the middle eye when leg stretched forward (vs. only reaches the level between tympanum to eye in the latter).

In mitochondrial DNA trees, Leptobrachella jinshaensis sp. nov. clustered as an independent clade and appears to be sister to a clade in comprising of L. bijie and L. chishuiensis . The latter two species also occur near the type locality of the new species. The new species differs from L. bijie by the following characters: webbing on toes absent (vs. webbing rudimentary in the latter), heels overlapping when thighs are positioned at right angles to the body (vs. just meeting in the latter), having longer call interval (132.7 ± 8.6, N = 109 in the new species vs.101.9 ± 6.4, N = 33 in the latter), having lower dominant frequency of 4525 ± 0.065 Hz vs. 4780.4 ± 76.5 Hz in the latter, having significantly higher value of SVL in males, and having significantly higher value of TYD and TL to SVL in males. Leptobrachella jinshaensis sp. nov. differs from L. chishuiensis by webbing on toes absent (vs. webbing rudimentary in the latter), tibia-tarsal articulation reaches the middle of eye when leg stretched forward (vs. reaches the tympanum or the level between tympanum to eye in the latter), the lower dominant frequency of calls 4500-4688 Hz (mean 4525 ± 0.065, 20 °C) vs. 6064-6284 Hz (6140.15 ± 69.35, 20 °C) in the latter, each call with two kinds of notes vs. only one kind of note in the latter, and having significantly higher value of HDW, SL, IOD, TYD, TEY and FL to SVL in males (all p -values <0.05; Table 4 ).

Ecology.

Leptobrachella jinshaensis sp. nov. is known from the type locality, Lengshuihe Nature Reserve , Jinsha County, Guizhou Province, China. Specimens of the new species are frequently found from stream covered with reeds, and under the rocks (Fig. 8 ) .

Etymology.

The specific name Leptobrachella jinshaensis refers to the distribution of this species, Jinsha County, Guizhou Province, China. We suggest its English common name "Jinsha leaf litter toads" and Chinese name "Jin Sha Zhang Tu Chan ( 金沙掌突蟾)”.

Figures

Figure 3. Plots of the first principal component (PC 1) versus the second (PC 2) for Leptobrachella jinshaensis sp. nov., L. bijie, and L. chishuiensis in males from a principal component analysis based on morphometric data.

Figure 4. Photos of the holotype specimen CIBCS 20200516004 of Leptobrachella jinshaensis sp. nov. A dorsal view B ventral view C lateral view D ventral view of hand E ventral view of foot.

Figure 5. Photos of the holotype CIBCS 20200516004 of Leptobrachella jinshaensis sp. nov. in life A dorsal view B ventral view C dorsal view of hand D ventral view of hand E ventral view of foot.

Figure 6. Colour variation in Leptobrachella jinshaensis sp. nov. A dorsal view of the male specimen CIBJS 20200516002 B dorsal view of the male specimen CIBJS 20200516005 C ventral view of the male specimen CIBJS 20200516005 D ventral view of the male specimen CIBJS 20200516003.

Figure 7. Advertisement calls of the holotype CIBCS 20200516004 of Leptobrachella jinshaensis sp. nov. A waveform showing one second contains 4 calls B sonogram showing one second contains 4 calls C waveform showing 0.4 second contains a call D sonogram showing 0.4 second contains a call.

Figure 8. Habitats of Leptobrachella jinshaensis sp. nov. in the type locality Lengshuihe Nature Reserve, Jinsha County, Guizhou Province, China. Forest and a mountain stream in the type locality (insert holotype CIBCS 20200516004 in life in the field).