Leptobrachella shangsiensis, Chen & Liao & Zhou & Mo, 2019

Chen, Weicai, Liao, Xiaowen, Zhou, Shichu & Mo, Yunming, 2019, A new species of Leptobrachella (Anura: Megophryidae) from southern Guangxi, China, Zootaxa 4563 (1), pp. 67-82 : 72-79

Leptobrachella shangsiensis sp. nov.

Figs. 2–3

Holotype. NHMG1704002 , adult male ( Fig. 2 A–F), collected at Shiwandashan National NR, Guangxi Province, China (22.455° N, 107.048° E; alt. 500 m). Collected on 26 April 2017 by Weicai Chen, Yunming Mo, Xiaowen Liao and Shichu Zhou.

Paratypes. NHMG1401024–031 , NHMG1704003–004 , ten adult males, NHMG1401032–034 , three adult females, collected at same locality as holotype on 3 Jan. 2014 by Weicai Chen and Yunming Mo . NHMG201604001 , one adult female, collected at same locality as holotype on 25 April 2016 by Weicai Chen and Yunming Mo . NHMG1704005 , one adult female, collected at same locality as holotype on 26 April 2017 by Weicai Chen and Yunming Mo .

Etymology. The specific epithet is in reference to the type locality of Shangsi County, Guangxi Province, China. Suggested English name is Shangsi Leaf Litter Toad.

Diagnosis. The specimens were assigned to the genus Leptobrachella on the basis of the following characters: small body size, having an elevated inner metacarpal tubercle, having macro-glands on body (including supraaxillary, femoral and ventrolateral glands), lacking vomerine teeth and having small tubercles on eyelids (Dubois 1980; Lathrop et al. 1998; Delorme et al. 2006). Leptobrachella shangsiensis sp. nov. is distinguished from its congeners by a combination of (1) SVL 24.9–29.4 mm in males (n = 11) and 30.8–35.9 mm in females (n = 5), (2) black supratympanic fold with dark reddish rim, (3) ventrolateral glands distinct, forming a broken line, (4) ventral surface yellowish creamy-white with marble texture, (5) iris copper in the upper and silver in the lower fifth and (6) toe webbing basal and lateral fringes distinct, narrow.

Description of holotype. Head width greater than head length (HW / HL = 1.15); snout bluntly rounded in profile and dorsal view, projecting slightly over lower jaw; nostril oval-shaped and closer to tip of snout than eye; canthus rostralis distinct; loreal region distinctly sloping, concave; pupil vertical; diameter of eye less than length of snout (ED / SNT = 0.78); tympanum distinct, rounded, diameter 55% that of eye (TD / ED = 0.55); tympanic rim elevated relative to skin of temporal region; vomerine teeth absent; pineal ocellus absent; vocal sac openings present, located laterally on floor of mouth; tongue large with shadow notch at posterior tip; supratympanic fold distinct, running from corner of eye to axillary gland ( Fig. 2 A–D). Forelimbs. Forelimbs thin, slender; tips of fingers rounded, slightly swollen; relative fingers lengths I <II <IV <III; nuptial pad absent; subarticular tubercles absent; a large, inner palmar tubercle separated from small, laterally compressed outer palmar tubercle; finger webbing and dermal fringes absent ( Fig. 2 E ). Hindlimbs. Hindlimbs slender; tips of toes rounded, slightly swollen, similar those of fingers; relative toe lengths I <II <V <III <IV; subarticular tubercles absent, replaced by distinct dermal ridges; larger, oval inner metatarsal tubercle pronounced, outer metatarsal tubercle absent; toe webbing basal; lateral fringes distinct, narrow ( Fig. 2 F ). Skin texture and skin glands. Skin on dorsum mostly smooth with numerous tiny tubercles; upper eyelid with small tubercles; ventral skin smooth; pectoral glands visible; femoral glands oval, approximately 1.1 mm in diameter, located on posteroventral surface of thighs, closer to knee than to vent; supra-axillary gland small, oval, approximately 1.1 mm; ventrolateral glands distinct, forming a broken line ( Fig. 2 C, D ).

Color of holotype in life. Dorsum reddish brown with dark brown markings between eyes and scapular region, and scattered some deep reddish tubercles concentrated on upper eyelid and scapular region; black supratympanic fold with dark reddish rim; canthus rostralis with black spots; lateral surfaces of trunk with creamy whitish spots, scattered with about 5 spots; transverse dark-brown bars present on dorsal surface of thighs, tibia, and lower arms; elbows and upper arms orange with light reddish-brown spots on tubercles; ventral surface yellowish creamy-white with marble texture; ventral surfaces of forelimbs and hindlimbs pinkish milk-white with dense whitish speckling; two distinct blackish-grey spots on edge of upper jaw located from snout to area under eye; supra-axillary gland milk-white; femoral and ventrolateral glands white. Iris copper in the upper and silver in the lower fifth ( Fig. 2 A–D).

Color of holotype in preservative. In preservation, coloration fades to dark grey-brown on dorsum, forelimbs, and hindlimbs. Transverse dark-brown bars are distinct on forelimbs and hindlimbs. Ventral surface is creamywhite. Margin of throat and ventrolateral surfaces of forelimbs and hindlimbs are pale-brown. Macro-glands including supra-axillary glands, femoral and ventrolateral glands are creamy.

Measurements of holotype (mm): SVL 26.8, HL 8.1, HW 9.3, SNT 4.6, ED 3.8, IOD 2.8, TD 2.1, TED 1.3, IN 3.2, EN 1.8, TIB 12.9, FLL 13.4, THL 14.1, PL 12.0, ML 7.0, FEM 1.1.

Variation. Measurements of the type series are shown in Table 2. Females (mean SVL 33.3 ± 2.0, n = 5) have larger body size than males (mean SVL 27.4 ± 1.1, n = 11). In life, all specimens have similar coloration ( Fig. 3 ), but in preservation, some specimens have slightly darker brown compared to holotype.

Advertisement call. Call descriptions are on the basis of the calls of the holotype, recorded at an ambient temperature of 21.5°C. Calls of L. shangsiensis sp. nov. consisted of a single note, with call duration 64–69 ms (66.03 ± 1.15, n = 30), call repetition rate 3.4 s and intercall interval 184–289 ms (250.53 ± 31.07, n = 30). The dominant frequency was between 5.5–6.5 kHz, but fundamental frequency and harmonics were not clear ( Fig. 4 ).

Ecology and distribution. All specimens were found in an evergreen forest in Shiwandashan National NR located at an elevation of 450–550 m ( Fig. 5A ). Males were calling on rocks within or adjacent to rocky streams at night between 1930–2400 h. Leptobrachella shangsiensis sp. nov. is only known from Shiwandashan National NR.

Comparisons.

Leptobrachella shangsiensis sp. nov. differs from all other Leptobrachella species based on morphological, molecular and acoustic data. Phylogenetically, L. shangsiensis sp. nov., L. aereus , L. minimus , L. nahangensis , L. nyx , L. pelodytoides , L. pluvialis , L. ventripunctatus and L. wuhuangmontis form a clade. Genetically, among this clade, the smallest genetic distance is 5.9% ( L. shangsiensis sp. nov. and L. nyx ) and the largest genetic distance is 10.3% ( L. shangsiensis sp. nov. and L. ventripunctatus ). However, L. shangsiensis sp. nov. can be distinguished from the above-mentioned species by morphological characters. First, L. aereus differs from L. shangsiensis sp. nov. by having a uniformly bronze iris (vs. iris copper in the upper and silver in the lower fifth), the higher frequency calls (6.2–7.9 kHz at 22.4–25.7°C in L. aereus vs. 5.5–6.5 kHz at 21.5°C in the new species) and absent a distinct black supratympanic line and no black spots on flanks (vs. present a black supratympanic line and black spots on flanks). Leptobrachella minimus differs from L. shangsiensis sp. nov. by having no lateral fringes on toes (vs. present narrow lateral fringes on toes) and iris dark gold above and grey below (vs. iris copper in the upper and silver in the lower fifth). Leptobrachella nahangensis differs from L. shangsiensis sp. nov. by having a large body size (male SVL 40.8 mm vs. SVL 24.9–29.4 mm), a uniformly gold iris (vs. iris copper in the upper and silver in the lower fifth) and no lateral fringes on toes (vs. present narrow lateral fringes on toes). Leptobrachella nyx differs from L. shangsiensis sp. nov. by having a relatively large body size (SVL 26.7–32.6 mm in males and 37.0–41.0 mm in females vs. SVL 24.9–29.4 mm in males and 30.8–35.9 mm in females); lateroventral glandular ridge poorly distinct (vs. distinct); dermal ridges under toes rather poorly distinct (vs. distinct); greyish-brown dorsum with dark regularly set rounded spots (vs. reddish brown dorsum); absent dermal fringe along toe V (vs. present); posterior part of thigh with glandular warts (vs. without glandular warts); HW / HL = 0.95 (vs. HW / HL = 1.15); ED / SNT = 1.00 (vs. ED / SNT = 0.78). Leptobrachella pelodytoides differs from L. shangsiensis sp. nov. by having wide webbing on toes (vs. basal toe webbing in L. shangsiensis sp. nov.), poorly distinct dermal ridges under toes (vs. distinct) and present longitudinal skin folds on dorsum (vs. absent). Leptobrachella pluvialis differs from L. shangsiensis sp. nov. by having a relatively small body size (male SVL 21.3–22.3 mm vs. 24.9–29.4 mm), absent dermal fringes on toes (vs. present), dirty white with dark brown marbling on venter (vs. yellowish creamywhite with marble texture) and dark golden iris (vs. iris copper in the upper and silver in the lower fifth). Leptobrachella ventripunctatus differs from L. shangsiensis sp. nov. by having a bicolored iris, copper above and grey-brown below (vs. iris copper in the upper and silver in the lower fifth), absent lateral fringes on toes (vs. present narrow lateral fringes on toes), chest and belly with dark brown spots (vs. yellowish creamy-white ventral surface with marble texture), present longitudinal skin folds on dorsum (vs. absent) and different dominant frequency (6.1–6.4 kHz at 15.0°C vs. 5.5–6.5 kHz at 21.5°C in L. shangsiensis sp. nov.). Leptobrachella wuhuangmontis differs from L. shangsiensis sp. nov. by having a greyish-white ventral surface mixed by tiny white and black dots (vs. yellowish creamy-white ventral surface with marble texture), distinct dark brown blotches on flanks from groin to axilla (vs. about 5 spots on flanks) and rough skin on dorsum body and limbs with skin ridges and dense conical tubercles (vs. nearly smooth dorsal skin with numerous tiny tubercles).

Among the genus Leptobrachella , fifteen species ( L. baluensis , L. bondangensis , L. brevicrus , L. fusca , L. itiokai , L. juliandringi , L. lateralis , L. mjobergi , L. natunae , L. nokrekensis , L. palmata , L. parva , L. platycephala , L. serasanae and L. tamdil ) have no molecular data. Geographically, these species occur in allopatry with L. shangsiensis sp. nov. Leptobrachella baluensis , L. brevicrus , L. itiokai , L. juliandringi , L. mjobergi , L. palmata , L. parva and L. platycephala come from Malaysia; L. bondangensis , L. fusca , L. natunae and L. serasanae from Indonesia; L. lateralis , L. nokrekensis and L. tamdil from northeast India. Morphologically, L. baluensis (male SVL 14.9–15.9 mm), L. bondangensis (male SVL 17.8 mm), L. brevicrus (male SVL 17.1–17.8 mm), L. fusca (male SVL 16.3 mm), L. itiokai (male SVL 15.2–16.7 mm), L. juliandringi (SVL17.0– 17.2 mm in males and 18.9–19.1 mm in females), L. mjobergi (male SVL 15.7–19.0 mm), L. natunae (male SVL 17.6 mm), L. palmata (male SVL 14.4–16.8 mm), L. parva (SVL15.0– 16.9 mm in males and 17.8 mm in female) and L. serasanae (female 16.9 mm) have a small body size (vs. SVL 24.9–29.4 mm in males and 30.8–35.9 mm in females in L. shangsiensis sp. nov.). Furthermore, L. baluensis , L. brevicrus , L. bondangensis , L. fusca , L. itiokai , L. juliandringi , L. mjobergi , L. natunae , L. palmata , L. parva and L. serasanae exhibit an arrow-like projection of digital tip (vs. no arrow-like projection of digital tip). Leptobrachella lateralis has no lateral fringes on toes (vs. present narrow lateral fringes on toes). Leptobrachella nokrekensis has reddish orange irises in the upper (vs. irises copper in the upper and silver in the lower fifth). Leptobrachella platycephalus has a large body size (male SVL 35.1 mm vs. SVL 24.9–29.4 mm) and orange red or reddish brown irises (vs. irises copper in the upper and silver in the lower fifth). Leptobrachella tamdil has wide lateral fringes on toes (vs. present narrow lateral fringes on toes) and wide webbing on toes (vs. basal toe webbing).

Leptobrachella shangsiensis sp. nov. occurs in sympatry with L. sungi , but L. sungi has a large body size (male SVL 48.3–52.7 mm vs. SVL 24.9–29.4 mm), gold green iris (vs. iris copper in the upper and silver in the lower fifth), absent a distinct black supratympanic line (vs. present) and absent black spots on flanks (vs. present). Leptobrachella laui and liui have a relatively widespread distribution in China. However, L. laui differs from L. shangsiensis sp. nov. by having no black supratympanic fold (vs. present), moderate dermal fringes on fingers (vs. absent), throat transparent pink with brown dusting along anterior margin (vs. throat yellowish creamy-white with marble texture) and head slightly longer than wide (vs. HW / HL = 1.15). Leptobrachella liui differs from L. shangsiensis sp. nov. by having wide lateral fringes on toes (vs. narrow lateral fringes on toes), creamy-white belly with dark brown spots on chest and margins (vs. yellowish creamy-white belly with marble texture), longitudinal ridges under toes interrupted at the articulations (vs. not interrupted) and greyish-brown dorsal coloration in life (vs. brown or reddish-brown dorsal coloration). From the rest 11 known Leptobrachella species from China, L. shangsiensis sp. nov. differs from L. alpinus by having a different dominant frequency (6.7 kHz at 16°C in L. alpinus vs. 5.5–6.5 kHz at 21.5°C in L. shangsiensis sp. nov.) and wide lateral fringes on toes (vs. present narrow lateral fringes on toes in L. shangsiensis sp. nov.). Leptobrachella bourreti exhibits a copper above and golden below iris (vs. iris copper in the upper and silver in the lower fifth), a relatively large body size (male SVL 28.0– 36.2 mm vs. SVL 24.9–29.4 mm in L. shangsiensis sp. nov.) and poorly distinct dermal ridges under toes (vs. distinct). Leptobrachella eos has a relatively large body size (male SVL 33.1–34.7 mm in L. eos vs. SVL 24.9–29.4 mm in L. shangsiensis sp. nov.), absent black spots on flanks (vs. present), iris orange above and light gold below (vs. iris copper in the upper and silver in the lower fifth in L. shangsiensis sp. nov.), absent a black supratympanic line (vs. present) and wide lateral fringes on toes (vs. present narrow lateral fringes on toes in L. shangsiensis sp. nov.). Leptobrachella mangshanensis has a bicolored iris with bright orange upper and greyish cream below (vs. iris copper in the upper and silver in the lower fifth in L. shangsiensis sp. nov.) and nearly smooth dorsal skin with some small, orange, tubercles and irregular, dark brown stripes (vs. nearly smooth dorsal skin with numerous tiny tubercles in L. shangsiensis sp. nov.). Leptobrachella maoershanensis has a bicolored iris with orange above and silver below (vs. iris copper in the upper and silver in the lower fifth in L. shangsiensis sp. nov.), creamy-white ventral surface with irregular black spots (vs. yellowish creamy-white ventral surface with marble texture) and shagreened dorsal skin small tubercles and longitudinal folds (vs. nearly smooth dorsal skin with numerous tiny tubercles in L. shangsiensis sp. nov.). Leptobrachella oshanensis has a relatively low dominant frequency (4.4–4.6 kHz at 14°C in L. oshanensis vs. 5.5–6.5 kHz at 21.5°C in L. shangsiensis sp. nov.), absent lateral fringes on toes (vs. present narrow lateral fringes on toes in L. shangsiensis sp. nov.) and present wide webbing on toes (vs. basal toe webbing in L. shangsiensis sp. nov.). Leptobrachella purpurus has a relatively low dominant frequency (4.3– 4.5 kHz at 15°C in L. purpurus vs. 5.5–6.5 kHz at 21.5°C in L. shangsiensis sp. nov.), a dull white venter with indistinct grey dusting (vs. yellowish creamy-white ventral surface with marble texture in L. shangsiensis sp. nov.) and a bicolored iris with orange yellow upper half and sliver white lower half (vs. iris copper in the upper and silver in the lower fifth in L. shangsiensis sp. nov.). Leptobrachella tengchongensis has a uniformly dark brown iris (vs. iris copper in the upper and silver in the lower fifth in L. shangsiensis sp. nov.), shagreened dorsal skin with small tubercles (vs. nearly smooth dorsal skin with numerous tiny tubercles in L. shangsiensis sp. nov.) and white venter with dark brown blotches (vs. yellowish creamy-white ventral surface with marble texture in L. shangsiensis sp. nov.). Leptobrachella yingjiangensis has a bicolored iris with orange yellow above and sliver white below (vs. iris copper in the upper and silver in the lower fifth in L. shangsiensis sp. nov.), wide lateral fringes on toes (vs. narrow lateral fringes on toes in L. shangsiensis sp. nov.), shagreened dorsal skin with fine, round brown tubercles (vs. nearly smooth dorsal skin with numerous tiny tubercles in L. shangsiensis sp. nov.), ventral surface of body creamy white and scattered with distinct small dark brown flecks on chest and lateral sides of belly (vs. yellowish creamywhite ventral surface with marble texture in L. shangsiensis sp. nov.) and a different dominant frequency (5.7–5.9 kHz at 19°C in L. yingjiangensis vs. 5.5–6.5 kHz at 21.5°C in L. shangsiensis sp. nov.). Leptobrachella yunkaiensis has a pinkish surface of belly with distinct or indistinct light dark brown speckling and black tympanum (vs. yellowish creamy-white belly and brown tympanum in L. shangsiensis sp. nov.) and shagreened dorsal skin with skin ridges and raised warts (vs. nearly smooth dorsal skin with numerous tiny tubercles in L. shangsiensis sp. nov.)

Besides the above-mentioned species, the remaining ones (35 of 71 species) belong to different phylogenetic clades, exhibit high genetic variation (ranging from 11.9% to 19.0%) and allopatric distribution. Leptobrachella arayai , L. dringi , L. fritinniens , L. gracilis , L. hamidi , L. heteropus , L. kajangensis , L. kecil , L. marmoratus , L. maurus , L. melanoleucus , L. pictus , L. platycephalus , L. sabahmontanus and L. solus lack supra-axillary and ventrolateral glands (vs. present in L. shangsiensis sp. nov.). The following species, L. applebyi (reddish brown with white specking), L. ardens (reddish brown with white specking), L. bidoupensis (reddish brown with white specking), L. botsfordi (reddish brown with white specking), L. croceus (bright orange), L. maculosus (brown, less white specking), L. melicus (reddish brown with white specking), L. pallidus (reddish brown with white specking), L. puhoatensis (deep reddish brown), L. pyrrhops (reddish brown with white specking) and L. tadungensis (reddish brown with white specking) have a non-creamy-white venter (vs. yellowish creamy-white ventral surface with marble texture in L. shangsiensis sp. nov.). Leptobrachella applebyi has a small body size (male SVL 19.6–22.3 vs. SVL 24.9–29.4 mm in L. shangsiensis sp. nov.), but L. zhangyapingi has a large body size (male SVL 45.8– 52.5 mm vs. SVL 24.9–29.4 mm in L. shangsiensis sp. nov.). For iris coloration, L. applebyi has a gold iris, L. ardens brown, L. bidoupensis reddish above and silver below, L. botsfordi uniformly brownish gold, L. firthi bright gold, L. fuliginosis reddish orange above and gold below, L. kalonensis gold, L. kecil dark red, L. maculosus bronze, L. melanoleucus orange above and silver below, L. melicus gold, L. pallidus dark brown, L. pyrrhops orange, L. rowleyae copper tint in upper half fading to golden in lower third, L. solus dark red above and dark brown below, L. tadungensis gold, L. tuberosus gold and L. zhangyapingi gold above and grey below. Leptobrachella croceus , L. firthi , L. pallidus , L. tuberosus and L. zhangyapingi lack a distinct black supratympanic line (vs. present a black supratympanic line in L. shangsiensis sp. nov.). Leptobrachella applebyi , L. ardens , L. crocea , L. kalonensis , L. macrops , L. maculosus , L. melica , L. pallidus , L. pyrrhops , L. rowleyae , L. tadungensis and L. tuberosa have no lateral fringes on toes (vs. present narrow lateral fringes on toes in L. shangsiensis sp. nov.). Leptobrachella firthi , L. isos , L. khasiorum and L. zhangyapingi have wide lateral fringes on toes (vs. present narrow lateral fringes on toes in L. shangsiensis sp. nov.). Leptobrachella ardens , L. kalonensis , L. maculosus , L. pallidus , L. petrops , L. rowleyae and L. tadungensis have no webbing on toes (vs. basal toe webbing in L. shangsiensis sp. nov.). Leptobrachella botsfordi , L. firthi , L. isos , L. pallidus , L. petrops , L. tuberosa and L. zhangyapingi have no black spots on flanks (vs. present).

Finally, calls of L. shangsiensis sp. nov. consist of a single note with a dominant frequency of 5.5–6.5 kHz (at 21.5°C). The dominant frequency of 5.5–6.5 kHz further distinguishes the call of L. shangsiensis sp. nov. from that of the lower frequency calls of L. applebyi (4.0–4.3 kHz at 21.5°C), L. ardens (3.1–3.4 kHz at 21.4–24.7°C), L. bidoupensis (1.9–3.8 kHz at 19.0–21.0°C), L. botsfordi (2.6–3.4 kHz at 14°C), L. croceus (3.0–4.3 kHz at 21.6– 25.1°C), L. fuliginosus (2.1–2.8 kHz at 19.3–19.6°C), L. kalonensis (2.8 kHz at 26.4°C), L. maculosus (2.7–2.8 kHz at 23.3–24.1°C), L. melicus (2.6–4.0 kHz at 26.1–26.2°C), L. pallidus (2.4–2.7 kHz at 14.0–21.4°C), L. pyrrhops (1.9–2.2 kHz at 25°C), L. rowleyae (3.2–3.5 kHz at 21.0°C), L. tadungensis (2.6–3.1 kHz at 12.9–22.3°C) and L. tuberosus (2.6–2.8 kHz at 22.5–24.5°C).

Figures

FIGURE 2. Holotype of Leptobrachella shangsiensis sp. nov. (NHMG1704002): (A) Dorsal view, (B) dorsolateral view, (C) flank and lateral view, (D) ventral view, (E) volar view of the left hand, and (F) thenar view of the left foot.

FIGURE 3. Leptobrachella shangsiensis sp. nov. in habitat (Photo taken in situ).

FIGURE 4. The advertisement call of holotype of Leptobrachella shangsiensis sp. nov. Expanded about 2 s waveform with Oscillogram (top) and corresponding audiospectrogram (bottom). The ambient air temperature was 21.5°C.

FIGURE 5. (A) Breeding habitat of Leptobrachella shangsiensis sp. nov. and (B) deforestation in Shiwandashan National Nature Reserve, Guangxi Province, China.