Leptobrachella yunkaiensis Wang, Li, Lyu & Wang

Wang, Jian, Yang, Jianhuan, Li, Yao, Lyu, Zhitong, Zeng, Zhaochi, Liu, Zuyao, Ye, Youhua & Wang, Yingyong, 2018, Morphology and molecular genetics reveal two new Leptobrachella species in southern China (Anura, Megophryidae), ZooKeys 776, pp. 71-103 : 71

Leptobrachella yunkaiensis Wang, Li, Lyu & Wang sp. n. Figures 3, 4C1-C3

Holotype.

SYS a004665, adult male, collected on 15 April 2016 by Jian Wang (JW hereafter), Zhao-Chi Zeng (ZCZ hereafter), Ying-Yong Wang (YYW hereafter), Zu-Yao Liu (ZYL hereafter), Hai-Long He (HLH hereafter) and Zhi-Tong Lyu (ZTL hereafter) from Dawuling Forest Station (DWL hereafter) (22°16'32.9"N, 111°11'42.87"E; 1600 m a.s.l.), Maoming City, Guangdong Province, China.

Paratypes.

Collectors and locality data of paratypes were the same as holotype: adult males, SYS a004664 / CIB107272, SYS a004666-4669 and an adult female SYS a004663, collected on 15 April 2016, the other adult female, SYS a004690, collected on 16 April 2017.

Diagnosis.

(1) small size (SVL 25.9-29.3 mm in males, 34.0-35.3 mm in females), (2) dorsal skin shagreened with short skin ridges and raised warts, (3) iris bicolored, coppery orange on upper half and silver on lower half, (4) tympanum distinctly discernible, slightly concave, weakly black supratympanic line present, (5) dorsal surface yellowish-brown grounding, with distinct darker brown markings and rounded spots and scattered with irregular orange patches, (6) flanks with several dark blotches, (7) surface of belly pinkish, with distinct or indistinct light dark brown speckling, (8) supra-axillary, femoral, pectoral and ventrolateral glands distinctly visible, (9) absence of webbing and presence of distinct lateral fringes on fingers, toes with rudimentary webbing and wide lateral fringes, (10) longitudinal ridges under toes not interrupted at the articulations, and (11) dense conical spines present on lateral and ventral surface of tarsus, surface of tibia-tarsal, inner-side surface of shank and surface around cloacal region.

Comparisons.

Comparative morphological data of Leptobrachella yunkaiensis sp. n. with 66 recognized Leptobrachella species were obtained from examination of museum specimens (see Appendix 1) and from the references listed in Table 2. All comparative data were shown in Tables 4, 5.

Compared with the 24 known congeners of the genus Leptobrachella occurring south of the Isthmus of Kra, by the presence of supra-axillary and ventrolateral glands, L. yunkaiensis sp. n. 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 , all of which lacking supra-axillary and ventrolateral glands; and by the significantly larger body size, SVL 25.9-29.3 mm in males, 34.0-35.3 mm in females, L. yunkaiensis sp. n. differs from the smaller L. baluensis (14.9-15.9 mm in males), L. brevicrus (17.1-17.8 mm in males), L. itiokai (15.2-16.7 mm in males), L. juliandringi (17.0-17.2 mm in males and 18.9-19.1 mm in females), L. mjobergi (15.7-19.0 mm in males), L. natunae (17.6 mm in male), L. parva (15.0-16.9 mm in males and 17.8 mm in female), L. palmata (14.4-16.8 mm in males), L. serasanae (16.9 mm in female) and Dring’s (1983) Leptobrachella sp. 3 “baluensis” (15.0-16.0 mm in males).

Leptobrachella yunkaiensis sp. n. is most similar to L. laui and L. liui , but it can be distinguished by the larger body sized, SVL 34.0-35.3 mm in females (vs. SVL 28.1 mm in a single female of L. laui ; SVL 23.0-28.0 mm in females of L. liui ), presence of short skin ridge and raised warts on dorsum (vs. absent in L. laui ), black supratympanic line weak (vs. black supratympanic line distinct in L. liui ), longitudinal ridges under toes not interrupted at the articulations (vs. interrupted in L. liui ) (Figure 4), belly pinkish with distinct or indistinct speckling (vs. belly creamy white with dark brown dusting on margins in L. laui ; belly creamy white with dark brown spots on chest and margins in L. liui ).

From the remaining 40 known congeners (Table 5), with SVL 25.9-29.3 mm in six males, SVL 34.0-35.3 mm in two females in Leptobrachella yunkaiensis sp. n., it can be distinguished from the larger L. eos (males 33.1-34.7 mm, female 40.7 mm), L. nahangensis (male 40.8 mm), L. pyrrhops (males 30.8-34.3 mm), L. sungi (males 48.3-52.7 mm, females 56.7-58.9 mm) and L. zhangyapingi (males 45.8-52.5 mm), and the smaller L. applebyi (males 19.6-22.3 mm, females21.7-25.9 mm), L. melica (males 19.5-22.7 mm), and L. pluvialis (males 21.3-22.3 mm). By having wide fringes on toes, the new species differs from L. applebyi , L. ardens , L. crocea , L. kalonensis , L. lateralis , L. maculosa , L. macrops , L. melica , L. minima , L. nahangensis , L. nyx , L. oshanensis , L. pallida , L. pluvialis , L. pyrrhops , L. rowleyae , L. tadungensis , L. tuberosa , and L. ventripunctata , all of which have no lateral fringes on toes; L. bidoupensis , L. bourreti , L. fuliginosa , and L. sungi , all of which have weak lateral fringes on toes; L. botsfordi , L. maoershanensis , L. pelodytoides , L. petrops , L. puhoatensis , and L. tengchongensis , all of which have narrow lateral fringes on toes; L. alpinus , L. firthi , and L. isos , all of which have wide lateral fringes only in males. With rudimentary webbing on toes, the new species differs from L. ardens , L. kalonensis , L. maculosa , L. oshanensis , L. pallida , L. petrops , L. rowleyae , and L. tadungensis , all of which have no webbing on toes; L. pelodytoides , L. sungi , and L. tamdil , all of which have wide webbing on toes. By having black spots on flanks, the new species differs from L. aerea , L. botsfordi , L. eos , L. firthi , L. isos , L. pallida , L. petrops , L. tuberosa , and L. zhangyapingi , all of which have no black spots on flanks. With belly pink with distinct or indistinct speckling, the new species differs from L. bourreti , L. eos , L. firthi , L. khasiorum , L. lateralis , L. minima , L. nahangensis , and L. nokrekensis , all of which have creamy white belly without patterns; from L. macrops , which have greyish-violet with white speckling; from L. purpura , which have dull white belly with indistinct grey dusting; and from L. yingjiangensis , which have creamy white belly with dark brown flecks on chest and margins. By dorsal skin shagreened with short skin ridges and raised warts, the new species differs from L. purpura , L. yingjiangensis and L. tengchongensis , all of which have shagreened dorsal skin with small tubercles, and from L. macrops , which have no skin ridges dorsally.

Description of holotype.

Adult male. Body size small, SVL in 28.7 mm. Head length slightly larger than head width, HDL/HDW 1.03; snout slightly protruding, projecting slightly beyond margin of the lower jaw; nostril equidistance between snout and eye; canthus rostralis gently rounded; loreal region slightly concave; interorbital space flat, larger internarial distance; pineal ocellus absent; vertical pupil; snout length slightly larger than eye diameter, SNT/EYE 1.03; tympanum distinct, rounded, and slightly concave, diameter smaller than that of the eye and larger than tympanum-eye distance, TMP/EYE 0.46 and TEY/TMP 0.47; weakly black supratympanic line present; vomerine teeth absent; vocal sac openings slit-like, located posterolaterally on floor of mouth in close proximity to the margins of the mandible; tongue deeply notched behind; supratympanic ridge distinct, extending from posterior corner of eye to supra-axillary gland; tubercles present on supratympanic ridge.

Tips of fingers rounded, slightly swollen; relative finger lengths I = II = IV <III; nuptial pad absent; subarticular tubercles absent; a large, rounded inner palmar tubercle distinctly separated from small, round outer palmar tubercle; absence of webbing and presence of distinct lateral fringes on fingers. Tips of toes like fingers; relative toe length I <II <V <III <IV; subarticular tubercles absent; distinct dermal ridges present under the 3rd to 5th toes; large, oval inner metatarsal tubercle present, outer metatarsal tubercle absent; toes webbing rudimentary; wide lateral fringes present on all toes. Tibia 43% of snout-vent length; tibiotarsal articulation reaches to middle of eye; heels just meeting each other when thighs are appressed at right angles with respect to body.

Skin on dorsum shagreened and scattered with fine, round tubercles; short skin ridges and raised warts on dorsum surface present; ventral skin smooth; pectoral gland and femoral gland large, oval; pectoral glands greater than tips of fingers and femoral glands; femoral gland situated on posteroventral surface of thigh, closer to knee than to vent; supra-axillary gland raised. Ventrolateral gland distinctly visible, forming an incomplete line. Dense conical spines on lateral and ventral surface of tarsus, surface of tibia-tarsal, inner-side surface of shank and surface around cloacal region present.

Measurements of holotype

(in mm).SVL 28.7, HDL 10.3, HDW 10.0, SNT 3.8, EYE 3.7, IOD 2.9, IND 2.8, TMP 1.7, TEY 0.8, TIB 12.4, ML 7.2, PL 12.1, LAHL 12.3, HLL 38.3.

Coloration of holotype in life.

Dorsal surface orange-brown with distinct dark brown blotches edged distinct light orange pigmentation. A dark brown triangular pattern between eyes, connected to the dark brown W-shaped marking between axillae. Tympanum black. Orange-brown tubercles present on dorsum of body and limb, those on flanks much distinct and dense; anterior upper lip with distinct blackish brown patches; transverse dark brown bars on dorsal surface of limbs; indistinct dark brown blotches on flanks from groin to axilla; elbow and upper arms without dark bars but with distinct coppery orange coloration; fingers and toes with indistinct dark brown blotches.

Surface of throat creamy white and scattered with small whitish dots; belly pinkish and scattered with small brown speckling; ventral surface of thighs pinkish and scattered with small light orange-brown spots. Supra-axillary coppery orange; femoral, pectoral and ventrolateral glands whitish orange. Iris bicolored, coppery orange on upper half and silver on lower half.

Coloration of holotype in preservative.

Dorsum of body and hindlimbs dark brown while dorsum of forelimbs yellowish brown; transverse bars on limbs become more distinct, dark brown patterns, markings and spots on back become indistinct. Ventral surface of body yellowish brown, with brown marbling on sides and chest. Orange supra-axillary, femoral, pectoral and ventrolateral glands fade to greyish white (Figure 4C1-C3).

Sexual dimorphism.

Females with a larger body size than males, SVL 34.0-35.3 mm (34.7 ± 0.9) (vs. SVL 25.9-29.3 mm (27.6 ± 1.4) in males); presence of a single vocal sac in males (vs. absent in females); dense conical spines on lateral and ventral surface of tarsus, surface of tibia-tarsal, inner-side surface of shank, surface of thighs and surface around cloacal region distinct in males, and barely visible in females.

Variations.

All paratypes match the overall characters of the holotype except that: the heels just meeting each other when thighs are appressed at right angles with respect to body, tibiotarsal articulation reaches to middle of eye in holotype SYS a004665 (vs. tibiotarsal articulation reaches to anterior corner of eye in SYS a004666, reaches the posterior corner of eye in SYS a004669). Surface of belly scattered with distinctly dark brown speckling in holotype (vs. such speckling indistinct in female paratypes SYS a004663, 4690. Tympanum black in the holotype (vs. tympanum black grounding with orange speckling in SYS a004667-4668). Distinct black spots present on dorsum in the female paraype SYS a004690 (Figure 3).

Etymology.

The specific epithet, yunkaiensis , is in reference to the type locality, DWL of Guangdong, China located in the Yunkai Mountains Range. For the common name, we suggest "Yunkai Mountain’s Leaf Litter Toad", and Chinese name "Yun Kai Zhang Tu Chan ( 云开掌突蟾)”.

Distribution and habits.

Currently, Leptobrachella yunkaiensis sp. n. is known only from its type locality DWL of Guangdong Province (Figure 1). The new species was found along a clear-water rocky stream (ca. 2-3 m in width and ca. 20-30 cm in depth) and small nearby seeps in well-preserved montane evergreen broadleaf forest (1600 m a.s.l.) (Figure 5). During April and June, males were found calling mainly hidden under leaf litter, and some were found calling perching on the rocks or under rocks by the side of the stream. Females collected on April bear pure white oocytes.