Leptobrachella bashaensis, Lyu & Dai & Wei & He & Yuan & Shi & Zhou & Ran & Kuang & Guo & Wei & Yuan, 2020

Lyu, Jing-Cai, Dai, Liang-Liang, Wei, Ping-Fan, He, Yan-Hong, Yuan, Zhi-Yong, Shi, Wen-Li, Zhou, Sheng-Lun, Ran, Si-Yu, Kuang, Zhong-Fan, Guo, Xuan, Wei, Gang & Yuan, Guo, 2020, A new species of the genus Leptobrachella Smith, 1925 (Anura, Megophryidae) from Guizhou, China, ZooKeys 1008, pp. 139-157 : 139

publication ID	https://dx.doi.org/10.3897/zookeys.1008.56412
publication LSID	lsid:zoobank.org:pub:0D4C047F-1B79-4FE5-9ED4-D93C62BCF6A0
persistent identifier	https://treatment.plazi.org/id/6257CDCB-B124-4649-BE10-9A4874C67F20
taxon LSID	lsid:zoobank.org:act:6257CDCB-B124-4649-BE10-9A4874C67F20
treatment provided by	ZooKeys by Pensoft
scientific name	Leptobrachella bashaensis
status	sp. nov.

Treatment

Leptobrachella bashaensis sp. nov. Figs 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 ; Tables 1, 2, 3

Type material.

Holotype. GIB196403, adult male, from Basha Nature Reserve, Congjiang, Guizhou Province, China (25.8534°N, 108.7356°E, elevation 900 m. a.s.l.; Fig. 1 View Figure 1 ), collected by Jingcai Lyu and Liangliang Dai on 4 June 2019. Paratypes. GIB196401-02, GIB196404, GIB196406-07 (five adult males) collected from the holotype locality by Jingcai Lyu on 4 June 2019.

Diagnosis.

The new species is assigned to the genus Leptobrachella on the basis of the following characters: small size, rounded fingertips, presence of an elevated inner palmar tubercle not continuous to the thumb, presence of supra-axillary, femoral and ventrolateral glands, vomerine teeth absent, tubercles on eyelids, and pale vertical bar present on anterior tip of snout ( Dubois 1980, 1983; Ohler et al. 2011; Rowley and Cao 2009; Rowley et al. 2013). Leptobrachella bashaensis sp. nov. is distinguished from its congeners by a combination of the following morphological characters: (1) small size (SVL 22.9-25.6 mm in six adult males and 27.1 mm in one adult female), (2) head longer than wide, (3) externally distinct tympanum, (4) dorsal skin slightly shagreened with small tubercles and irregular brown stripes, (5) distinct dark spots on the flank, (6) creamy-white chest and off-white belly with irregular black spots, (7) grey-pinkish to dark brownish-violet ventral skin of limbs with numerous whitish speckles, (8) distinct ventrolateral glands, forming a distinct white line, (9) finger webbing and fringes absent, (10) toe webbing rudimentary and lateral fringes narrow, (11) longitudinal ridges under toes and not interrupted at the articulations, (12) a distinctly bicolored iris, typically bright orange in upper half, fading to silver in lower half.

Description of the holotype.

Adult male. SVL 24.0 mm; head slightly longer than wide (HDL/HDW = 1.10), rectangular in dorsal view (Fig. 3A, B View Figure 3 ); snout rounded in both ventral view and lateral view, protruding slightly beyond lower jaw (Fig. 3D View Figure 3 ); nostril oval, located closer to tip of snout than to eye; loreal region oblique; canthus rostralis distinct; eye large (EYE/HDL = 0.35), diameter slightly smaller than snout length (EYE/SNT = 0.88), notably protuberant in both dorsal and lateral view; pupil vertical; tympanum distinct, rounded, diameter smaller than that of eye (TMP/EYE = 0.60) (Fig. 3C View Figure 3 ); vomerine teeth absent; vocal sac openings slit-like, located posterolateral on floor of mouth; tongue long and moderately wide, with a shallow notch at posterior tip; supratympanic ridge distinct, running from eye towards axillary with raised tubercles. Forelimb long and slender, fingers long and slender, without webbing and lateral fringes; relative length of fingers II<I<IV<III; tips of fingers rounded and slightly swollen; nuptial pad absent; subarticular tubercles absent in fingers; inner metacarpal tubercle large and rounded, separated from laterally compressed and much smaller outer metacarpal tubercle (Fig. 4A, B View Figure 4 ). Hindlimb moderately long; tibia half of snout-vent length (TIB/SVL = 0.50); tibiotarsal articulation of adpressed limb reaching snout, well beyond anterior margin of eye, but not beyond snout tip; relative toe lengths I<II<V<III<IV; toe tips rounded and thickened; greatly reduced basal webbing present between all five toes; narrow lateral fringes present only on II and III toes (Fig. 4C, D View Figure 4 ); subarticular tubercles hardly discernible under toes II and III; dorsal skin slightly rough with small tubercles and irregular pustules; ventral skin smooth; oval supra-axillary gland present at forelimb base on ventral surface of axillary region (Fig. 3F View Figure 3 ); oval femoral glands distinct on posteroventral surface of thigh, closer to knee than to vent; ventrolateral glands forming a distinct line on flanks.

Coloration of holotype in life.

Dorsal surface of head and trunk brown with small, dark brown, irregularly shaped markings; large reverse-triangle dark brown marking between eyes, connected to the W-shaped mark between axillae (Fig. 3 View Figure 3 ); supratympanic ridge present; elbow to upper arm reddish in color; fine, distinct reddish tubercles scattered on upper eyelids, dorsal surfaces of head, body, and limbs. Ventral surface of throat and belly off-white, with faint spots; chest creamy white, with irregular black spots (Fig. 3G, H View Figure 3 ); ventral surfaces of lip and limbs covered with irregular white speckles; ventral surface of thighs grey-brown with white spots. Supra-axillary gland, ventrolateral glands, and femoral glands white. Iris bicolored: bright orange in upper half, silver in lower half, with black reticulations throughout. Fine, faint transverse dark brown bars on dorsal surface of fingers and toes, lower arms, tarsus, thighs, and tibia (Fig. 4 View Figure 4 ).

Coloration of holotype in preservation.

In preservative (75% ethanol), dorsal surface dark grey-brown, and ventral and lateral white glands not evident (Fig. 5 View Figure 5 ); ventral surface of throat, chest, belly, and interior portions of arms fade to creamy white, ventral surface of thighs dark brown with white spots; bars and blotches on dorsum and limbs are dark brown and less apparent. The color of the tympanum fades to brown.

Tadpoles.

Brown, narrow; BH 4.4 mm; BL 14.1 mm; BW 6.2; ED 2.0 mm; TH 3.8; SS 4.9 mm; TMW 3.4 mm; TL 29.3 mm; TOL 43.8 mm. TAL/TOL = 0.67, with a I:3+3/1+1:II labial tooth row formula (Fig. 6 View Figure 6 ). In life, dorsal surface of head dark brown with small, brown, irregularly shaped spot; air sac-shaped bulges on both sides of the body; upper lip and lower lip nearly round shape. Tadpoles were collected in the field from a stream surveyed on 16 October 2017 in Basha Nature Reserve by Lyu.

Etymology.

The specific epithet, " Leptobrachella bashaensis "/Basha Zhang Tu Chan (岜沙掌突蟾 in Chinese), refers to the location where the specimens were collected, Basha Nature Reserve of Guizhou Province, China.

Morphological variation.

Variation in size and body proportions of the type series are shown in Table 3 View Table 3 . Representative photographs of paratypes in life are shown in Fig. 7 View Figure 7 . In life, the dorsal surface of the head and trunk varies from olive-brown to reddish; the ventral surface of the lower jaw among these individuals varies from cream-yellow, pink, to grey; the ventral surface of chest and belly is grey-pink to white. There is variation among individuals in the shape of tubercles, pustules, black ventrolateral blotches, and dark stripes, bars on the dorsum or dorsal surface of limbs. The W-shaped marking between axillae is distinct in all individuals.

Natural history.

All specimens were collected at night in small streams in Basha Nature Reserve approximately 900 m elevation (Fig. 8 View Figure 8 ). Calling males were found along the streams, perching on large rocks, in rocky crevices, or under dead wood. Insect-like calls could be heard in June. The breeding season of this species is likely to occur from June to July, as females collected during these months were gravid, and males were heard calling only from June to the beginning of July. During both surveys, the number of males observed was much greater than females (males:females = 12:1).

Comparisons.

Leptobrachella bashaensis sp. nov. differs from all known Leptobrachella species distributed north of the Isthmus of Kra by a combination of male body size, externally distinct tympanum, and black spots on the flank, plus ventral coloration, degree of webbing and fringing on the toes, iris coloration, and dorsal skin texture.

Care was taken to differentiate Leptobrachella bashaensis sp. nov. from the five most morphologically and molecularly similar species, L. maoershanensis , L. laui , L. mangshanensis , L. yunkaiensis , and L. liui from China.

Leptobrachella bashaensis sp. nov. differs from its sister taxon L. maoershanensis by the following: smaller body size (SVL 22.9-25.6 mm in males, 27.1 mm in female vs 25.2-30.4 mm in males, 28.6 mm in female); bicolored iris with bright orange in upper half, fading to silver in lower half (vs typically bright orange-red in upper half, fading to silver in lower half); vertical and distinct narrow pupil (vs vertical and wide pupil); narrow lateral fringes present only on II and III toes (vs narrow lateral fringes present on all toes).

Leptobrachella bashaensis sp. nov. differs from L. laui in having slightly a smaller body size (SVL 22.9-25.6 mm in males, 27.1 mm in female vs 24.8-26.7 mm in males, 28.1 mm in female); bicolored iris with bright orange in upper half, fading to silver in lower half (vs uniformly coppery orange with fine black reticulations throughout); vertical and distinct narrow pupil (vs vertical and wide pupil); narrow lateral fringes present only on II and III toes (vs wide lateral fringes present on all toes); distinct black spots on the flank (vs indistinct black spots on the flank).

Leptobrachella bashaensis sp. nov. differs from L. mangshanensis by having slightly smaller body size (SVL 22.9-25.6 mm in males, 27.1 mm in female vs 22.2-27.8 mm in males, 30.2 mm in female); bicolored iris with bright orange in upper half, fading to silver in lower half (vs bright orange in upper half, greyish cream in lower half); narrow lateral fringes present only on II and III toes (vs weak lateral fringes on toes).

Leptobrachella bashaensis sp. nov. differs from L. yunkaiensis by having smaller body size (SVL 22.9-25.6 mm in males, 27.1 mm in female vs 25.9-29.3 mm in males, 34.0-35.3 mm in females); bicolored iris with bright orange in upper half, fading to silver in lower half (vs coppery orange in upper half and silver in lower half); narrow lateral fringes present only on II and III toes (vs wide lateral fringes present on all toes); distinct black spots on the flank (vs indistinct black spots on the flank).

Leptobrachella bashaensis sp. nov. differs from L. liui in having slightly smaller body size (SVL 22.9-25.6 mm in males, 27.1 mm in female vs 23.0-28.7 mm in males, 23.1-28.1 mm in females); vertical and distinctly narrow pupil (vs vertical and wide pupil); narrow lateral fringes present only on II and III toes (vs wide lateral fringes present on all toes).