Leptolalax maoershanensis

Yuan, Zhiyong, Sun, Ruida, Chen, Jinmin, Rowley, Jodi J. L., Wu, Zhengjun, Hou, Shaobing, Wang, Shaoneng & Che, Jing, 2017, A new species of the genus Leptolalax (Anura: Megophryidae) from Guangxi, China, Zootaxa 4300 (4), pp. 551-570: 553-559

publication ID

https://doi.org/10.11646/zootaxa.4300.4.5

publication LSID

lsid:zoobank.org:pub:7C14893E-F3F4-46C9-86BE-0A25E321347E

persistent identifier

http://treatment.plazi.org/id/0397C925-F27B-8530-FF14-930EFEDEFE38

treatment provided by

Plazi

scientific name

Leptolalax maoershanensis
status

sp. nov.

Leptolalax maoershanensis  sp. nov. Yuan, Sun, Chen, Rowley & Che

( Fig. 2–6View FIGURE 2View FIGURE 3View FIGURE 4View FIGURE 5View FIGURE 6)

Holotype. KIZ 046696View Materials, adult male from Antangping , Maoershan Nature Reserve, Ziyuan, Guangxi, China (25.9116°N, 110.4652°E, elevation 1575 m. a.s.l.; Fig. 1View FIGURE 1), collected by Zhiyong Yuan on 4 April 2016.GoogleMaps 

Paratypes. KIZ019385–86 (two adult males), KIZ045758 (adult male), KIZ046698–700 (three adult males), KIZ027229 (adult female) from the type locality collected by Jinmin Chen on 5 June 2015; KIZ019384 (adult male), KIZ027230–41 (11 adult males), KIZ046643 (adult male) and KIZ027234 (adult female) from the type locality collected by Zhiyong Yuan during April 2016.

Diagnosis. The new species is assigned to the genus Leptolalax  on the basis of the following characters: medium size, rounded finger tips, 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 & Cao 2009, Rowley et al. 2013). Leptolalax maoershanensis  sp. nov. is distinguished from its congeners by a combination of (1) medium size (SVL 25.2 mm – 30.4 mm in eight adult males and 29.1 mm in a one adult female), (2) head longer than wide, (3) externally distinct tympanum, (4) distinct black supratympanic line present, (5) dorsal skin shagreened with small tubercles and longitudinal folds, (6) distinct dark spots on the flank, (7) creamy-white chest and belly with irregular black spots, (8) grey-pinkish to dark brownish-violet ventral skin of limbs with numerous whitish speckles, (9) distinct ventrolateral glands, forming a distinct white line, (10) finger webbing and fringes absent, (11) toe webbing rudimentary and lateral fringes narrow, (12) longitudinal ridges indistinct under toes and not interrupted at the articulations, (13) a distinctly bicolored iris, typically bright orange-red in upper half, fading to silver in lower half.

Description of the holotype. SVL 28.8 mm; head slightly longer than wide (HDL/HDW = 1.25), triangular in dorsal view; snout rounded in both ventral view and lateral view, protruding slightly beyond lower jaw ( Fig. 3View FIGURE 3); nostril oval-shaped located closer to tip of snout than to eye; loreal region oblique; canthus rostralis distinct; eyes large (EYE/HDL = 0.33), eye diameter slightly smaller than snout length (EYE/SNT = 0.77), notably protuberant in both dorsal and lateral view, pupil vertical; tympanum distinct, rounded, diameter smaller than that of the eye ( TMP /EYE = 0.47); tympanic annulus notably elevated relative to supratympanic line; vomerine teeth absent; pineal ocellus absent; vocal sac openings slit-like, located posteriolaterally on floor of mouth; tongue long and moderate width, 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 ( Fig. 4View FIGURE 4); 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 small, laterally compressed and much smaller outer metacarpal. Hindlimb relatively long, tibia less than half of snoutvent length (TIB/SVL = 0.41); tibiotarsal articulation of adpressed limb reaching snout, but not beyond snout tip, posterior edge of tibiotarsal articulation reaches well beyond anterior margin of eye; relative toe length I<II<V<III<IV; toe tips rounded and thickened; greatly reduced basal webbing present between all five toes; narrow lateral fringes present on all toes, hardly discernible; subarticular tubercles distinct under toes II and III; distinct dermal ridges present under toes I, V and IV; large, oval inner metatarsal tubercle distinct, outer metatarsal tubercle absent; dorsal skin rough with small tubercles and irregular pustules; ventral skin smooth; oval supra – axillary gland distinct at forelimb basis on ventral surface of axillary region; oval femoral glands distinct on posteroventral surface of thigh, closer to knee than to vent; ventrolateral glands forming a distinct line on flanks. Skin on dorsum mostly rough with tiny and raised tubercles; ventral skin smooth; pectoral gland small, oval; femoral gland small, oval, on posteroventral surface of thigh, closer to knee than to vent; supra-axillary gland oval, raised. Ventrolateral glands forming distinct lines.

Color of holotype. In life, dorsal surface of head and trunk olive brown with large, dark brown, irregularly shaped markings; large reverse-triangle dark brown markings between eyes, connected to the W-shaped marking between axillae; faint transverse dark brown bars on dorsal surface of fingers and toes, lower arms, tarsus, thighs and tibia ( Fig. 3View FIGURE 3); upper lip barred with dark and light brown; one dark blotch between nostril and eyes on loreal region; black band along canthus rostralis, through eye, and continuing along supratympanic ridge, encompassing most of tympanum, terminating above axilla; supratympanic ridge present, elbow to upper arm is reddish in color; five large, irregularly-shaped black blotches on flanks from the groin to axilla; fine, distinct reddish tubercles scattered on upper eyelids, snout, dorsal surfaces of head, body and limbs. Ventral surface of throat, chest and belly creamy white with irregular black spots; ventral surfaces of lip, 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: copper in upper half, silver in lower third, with black reticulations throughout. In preservative, dorsal surface dark grey-brown with slightly paler limbs ( Fig. 5View FIGURE 5); ventral surface of throat, chest, belly and interior portions of arms fade to yellowish- whitish, ventral surface of thighs dark brown with white spots; bars and blotches on dorsum and limbs are more pronounced.

Morphological variation. Variation in size and body proportions of the type series are shown in Table 2. Representative photographs of paratypes in life are shown in Fig. 6View FIGURE 6. In life, the dorsal surface of the head and trunk varies from olive brown to reddish in color. Individuals vary in the number and size of tubercles, pustules, black ventrolateral blotches, and dorsal bars on the dorsum or dorsal surface of arms and legs. The W-shaped marking between axillae indistinct in some individuals (KIZ04663, 019384–86, 0 45758, 0 46699, 027232). The ventral surface of the throat is near immaculate creamy-white white in eight individuals (KIZ046700, KIZ046698, KIZ019385, 0 46643, 0 19384, 0 45768, 0 27230, 045771). The white speckles vary in number and size on the ventral surfaces of the lip and limbs.

Etymology. The specific epithet, “ maoershanensis  ”, is in reference to the type locality, Maoershan Nature Reserve.

Molecular relationships. A total of 511 base pairs (bp) alignment for the16S gene were obtained. The five sequences belonging to the newly acquired specimens (GenBank accession numbers: KY986930View Materials KY986934View Materials) share a same haplotype. The observed interspecific uncorrected p -distances between the new population from Maoershan and all species in the subgenus for which comparable sequences were available varied from 6.6% ( L. liui  ) to 19.5% ( L. gracilis  ). The smallest genetic distance was observed between L. bourreti  and L. eos  (4.6%). The individuals from Maoershan formed a monophyletic group with L. liui  and L. laui  , with high support in both analyses ( Fig. 2View FIGURE 2), but the relationships among these three species were not resolved. In combination with morphological differences (see below), we conclude that the newly collected Maoershan specimens represent a distinct species, and we describe it herein.

TABLE]. List of voucher specimens anđ GenBank accession numbers for all DNA sequences incluđeđ in this stuđy.

Natural history. All specimens were collected at night in small bamboo forest in Maoershan Nature Reserve at about 1550 m elevation ( Fig. 7View FIGURE 7). Calling males were found along the stream, perching on large rocks, rocky crevices or under deadwood. Insect-like calls could be heard during April and June. The breeding season of this species is likely to encompass April to July as females collected during these months were gravid, and males were heard calling only from April to the beginning of July (observed by Shaobing Hou, who conducted fieldworks in Maoershan each month from 2015 to 2016). During both surveys, the number of males observed was much greater than females (males: females = 5: 1 in June 2015 and 14: 1 in April 2016). The new species occurs in syntopy with Pachytriton inexpectatus Nishikawa, Jiang, Matsui  , & Mo, Megophrys  sp., Quasipaa boulengeri Günther  , during the same seasons.

Distribution. The species is currently only known from Maoershan Nature Reserve, Ziyuan, Guangxi, China.

Comparisons. Leptolalax maoershanensis  sp. nov. can be differentiated from all Leptolalax  species south of the Isthmus of Kra currently assigned in the subgenus Leptolalax  ( L. arayai  , L. dringi  , L. fritinniens  , L. gracilis  , L. hamidi  , L. heteropus  , L. kajangensis  , L. kecil  , L. marmoratus  , L. maurus  , L. pictus  , L. platycephalus  , L. sabahmontanus  and L. solus  ) in having supra-axillary and ventrolateral glands (vs. supra-axillary and ventrolateral glands absent).

Leptolalax maoershanensis  sp. nov. differs from all known Leptolalax  species distributed north of the Isthmus of Kra by a combination of male body size, presence of a distinct black supratympanic line, externally distinct tympanum, and black spots on the flank, plus ventral colouration, degree of webbing and fringing on the toes, iris coloration and dorsal skin texture (Table 3, Appendix II). Leptolalax maoershanensis  sp. nov.. can be further differentiated from the two most morphologically and molecularly similar species, L. laui  and L. liui  , from China, by having longitudinal ridges indistinct under the toes and not interrupted at the articulations (vs. distinct longitudinal ridges interrupted at the articulations in L. liui  ), dorsal skin with irregular pustules or glandular folds (vs. absence in L. laui  ) and ³6.6% divergence at the 16S gene fragment examined. From L. alpinus  , a morphologically similar species from China for which no comparable molecular data is available, the new species differs by having narrow lateral fringes on the toes (vs. wide lateral fringes), a smooth to finely shagreened dorsum with small tubercles and irregular pustules (vs. smooth dorsum without irregular pustules), head slightly longer than wide (vs. head width approximately equal to head length), and hindlimbs relatively long, with the tibiotarsal articulation of adpressed limbs reaching the snout (vs. tibiotarsal articulation of adpressed limb reaching anterior margin of eye).

KIZ

Kunming Institute of Zoology, Chinese Academy of Sciences

TMP

Transvaal Museum

Kingdom

Animalia

Phylum

Chordata

Class

Amphibia

Order

Anura

Family

Megophryidae

Genus

Leptolalax