Scutiger ching, Wang & Yu & Wu & Hou & Wang & Xiong & Ye & Duan & Li & Li & Jin & Yang & Che, 2025

Scutiger ching sp. nov. Wang, Yu, and Che ( Figs. 3 View FIGURE 3 , 10–12 View FIGURE 10 View FIGURE 11 View FIGURE 12 )

Holotype: KIZ 51834 View Materials , adult male, from the western slope of the Gaoligong Mountain , facing to the Dulong Valley , Gongshan County, Nujiang Prefecture, Yunnan Province, China ( 98.46359ºE, 27.84004ºN, elevation 2874 m, GCJ02 ). Collected by Kai Wang, Zhuo-Yu Lu, Yi-Lin Zhang, and Xian-Kun Huang on 27 May, 2023. GoogleMaps

Paratype ( one adult male, two adult females): KIZ 51836 View Materials , adult female, share the same collection information as the holotype ; KIZ 038604 View Materials , adult male , KIZ 038603 View Materials , adult female, collected by Zhong-Bin Yu, Dong An, and Tian-En Chen , from the Dulong Valley ( 98.50400ºE, 27.79778ºN, elevation 3006 m, GCJ02 ), collected by Zhongbin Yu, Dong An, and Xian-Kun Huang on 27 July 2021 GoogleMaps .

Etymology: The species name, ching , is derived from the language Trung, the language of the local ethic minority group (Dulong) at the type locality of the new species. It means small and slender, which describes the diagnostic body shape of the new species. We chose the native language of the Dulong People to honor the harmony between the local ethnic culture and nature ecosystem. We suggest Elf Lazy Toad as its English common name, and “ ƜÑÊẊḆ ” (Pinyin: Shan Jing Chi Tu Chan) as its Chinese common name.

Diagnosis: Scutiger ching sp. nov. can be diagnosed from congeners by a combination of the following characteristics: (1) body size small, SVL 37.5–45.1mm; (2) forearm and hand length long, LFHL 50.4–54.7% SVL in males; (3) posterior head short, PHL 40.4–43.2% HL; (4) inter-nare distance large, IND 26.3–30.6% HW; (5) snout long, SEL 36.7–43.2% HL; (6) eyes large, ED 28.8–33.1% HL; (5) single pair of pectoral glands and axillary glands present in males; (6) fine black spines present on pectoral glands, axillary glands, base of ventral forelimbs, peripheral ventral chin, ventral cloaca, and all tubercles on dorsal head, body, and limbs in breeding males; (7) vomerine teeth absence; (8) maxillary teeth fine, presence; (9) tongue slightly notched; (9) nuptial pads present on first three fingers in males, covered with enlarged black spines; (10) distinct enlarged, raised tubercles scattered on dorsal and lateral forearms and anterior brachium; (11) smaller, raised tubercles present on dorsal eyelids and supralabial as well as posterior jaw, covered with dense fine spinules during mating season in males; (12) vocal sacs present in males; (13) supratympanic fold strongly developed, extend posterior of axillary; (14) toes feebly webbed with weak dermal fringes; (15) parietal head flat; and (16) distinct, raised tubercles densely, irregularly scattered on dorsum and dorsal limbs, some large some fine.

Comparison: Morphologically, S. ching sp. nov. is most similar to S. tengchongensis , in which both species are closely distributed and have small body size, nuptial spines on the first three fingers, and spinules on dorsal surfaces of head, body, and limbs in males. However, S. ching sp. nov. can be diagnosed readily from S. tengchongensis by the presence of vocal sacs in males (vs. absence), irregularly scattered tubercles on dorsum (vs. regularly aligned as lateral rows), and by having longer hind limbs in males (HLL 148.3–156.5% SVL in males vs. 131.9–141.8%).

Additionally, S. ching sp. nov. is similar to S. gongshanensis , in which both species are closely distributed and having similar body size and vocal sacs in males. However, S. ching sp. nov. differs from S. gongshanensis by having nuptial spines on first three fingers in males (vs. only first two fingers) and much longer hind limbs in males (HLL HLL 148.3–156.5% SVL in males vs. 125.5–139.0%).

For remaining recognized species of the genus, S. ching sp. nov. differs from most recognized congeners (i.e. S. adungensis , S. biluoensis , S. glandulatus , S. jiulongensis , S. kanjiroba , S. maculatus , S. mammatus , S. meiliensis , S. muliensis , S. nyingchiensis , S. occitentalis , S. pingwuensis , S. spinosus , S. tuberculatus , S. wanglangensis ) by having a smaller adult body size (SVL < 40mm in males, < 46mm in female vs.> 55mm in both sexes). For the remaining congeners with similar body size, S. ching sp. nov. differs from the S. boulengeri complex (including S. boulengeri and S. bangdaensis , as well as the two synonyms of S. boulengeri , namely Cophophryne alticola and Aelurophryne tainingensis ), as well as S. bhutanensis , S. chintingensis , S. feiliangi , S. liupanensis , S. luozhaensis , S. ningshanensis , S. sikkimensis , and S. wolong by the presence of vocal sacs in males (vs. absence).

For the new species described above, S. ching sp. nov. differs from S. lisu sp. nov. by the presence of vocal sacs in males (vs. absence) and having a much smaller body size (SVL< 46 mm vs.> 75 mm); and from S. pardalotus sp. nov. by having more slender forelimbs (thick and more robust), a distinct body coloration (nearly uniform Olive Horn Color [Color 16] with faint, irregular Clay Color [Color 18] patches vs. Pale Pinkish Buff (Color 3) to Light Orange Yellow (Color 7) with Brunt Umber (Color 48) spots and dorsolateral stripes), and much weaker webbing on toes (rudimentary or no webbing vs. half-webbed).

Description of the holotype: Adult male, slim, small, SVL 37.5mm; head moderate, width about equal to length, HW 98.5% HL; parietal region flat; snout relatively long, projecting beyond jaw, SEL 40.4% HL; lateral supralabial convex posterior to nares; nares about equal between eye and snout, facing dorsolaterally, further apart from each other, IN 30.6% HW; loreal slightly concave; canthus rostralis distinct; eye raised, large, ED 33.1% HL, DEW 25.0% HL; iris ellipse shaped, vertically oriented; tympanum concealed; frontal and temporal flat; supratympanic folds well developed, raised, extending posteriorly to posterior jaw only.

Limbs slender; forearm long, FAL 54.7% SVL, slightly thicken toward elbows, FAW 24.4% FAL; fingers slender, free of webbing, finger length I<II<IV<III; enlarged, raised nuptial spines present dorsally on first two fingers and anterolaterally on third finger; distinctively raised tubercles present on forearm, dorsal hand, and on third and fourth fingers dorsally; metacarpal tubercles distinct, inner larger than outer; subdigital tubercles indistinct. Hindlimb relatively long, heels not meeting anteriorly and reaching posterior eyes with tip of longest toe when adpressed, HLL 156.5% SVL, FEM 45.6% SVL, TFL 70.9% SVL, TIB 40.0% SVL; foot longer than tibia, FL 126.7% TIL; toe tips rounded, toe length I<II <V <III <IV; dermal fringes feeble, webbing rudimentary, webbing formula I2 - –2 + II2–3 - III3–4 - IV4 - –3 - V; subdigital tubercles absent; subarticular tubercles absent, subdigital ridges distinct; inner metatarsal tubercle distinct, oval shaped, longer than first toe, outer metacarpal tubercle absent.

Dorsal skins of head, body, and limbs rough, with fine to medium sized tubercles densely scattered, each with one or cluster of black spinules; tubercles densely gathered on dorsal body, but smaller, fewer, and looser toward head and flank. Tubercles on basal branchium dense, irregular, singular and regular on forearm.

Spinules present on ventral lower lip; single pair of pectoral glands present on chest, ovel shape, elongated laterally, covered with fine spines; single pair of axillary gland present, distinct, smaller than pectoral, also covered with spines; few patches of spines also present on base of ventral brachium. Ventral cloaca also covered with scattered spinules. Remaining ventral surfaces smooth.

Coloration: The background coloration is Pale Horn Color (Color 11) to Olive Horn Color (Color 16). The lateral snout, loreal, and supratympanic folds are Walnut Brown (Color 27). In addition to the Walnut Brown (Color 27) transverse streak between eyes dorsally, these patterns together form a Pale Horn Color (Color 11) triangular patch on dorsal snout. The densely tuberculated region of the dorsum is Antique Brown (Color 24). Indistinct Antique Brown (Color 24) patches or streaks are present on dorsal limb, particularly prominent on dorsal hind limbs. The background coloration of ventral surfaces of head, limbs, and body are Pale Pinkish Buff (Color 3), which are heavily marbled with Flesh Color (Color 249), irregular patterns.

Variation: Sexual dimorphism is evident in the new species: in addition to the lack of vocal sacs, pectoral glands, and nuptial spines, the female paratype has more regularly aligned tubercles on dorsum (vs. irregularly scattered), thinner forearms ( FAL 15.9 % FAW vs. 21.5–24.4% in males), and shorter hind limbs ( HLL 135.7 % SVL vs. 148.3–156.5% in males). The paratype male ( KIZ 038604 View Materials ) is not in full breeding mode, and its sexually dimorphic characters are different from the holotype: all dorsal tubercles of the paratype lack black spinules, and the spines of pectoral gland, axillary glands, and dorsal fingers all lack black keratin layer. Webbing formula is consistent among all individuals, without signs of sexual dimorphism .

Natural history and conservation: Currently the new species is known from the type locality only, but it is likely to occur in similar alpine habitat further south along the Gaoligong Mountain. The holotype, the paratype female (KIZ 51836), and other uncollected individuals were found gathered in very shallow streams (less than 1 cm deep), and males were calling with a low voice from complex burrows at night. Because the paratype male (KIZ 038604) does not have nuptial spines on pectoral and axillary glands in late July, the breeding season of S. ching sp. nov. is likely between early May and early July. Individuals were extremely shy and stopped calling when disturbed slightly. Although S. lisu sp. nov., Zhangixalus cf. puerensis , and Rana suchinae were found sympatric with the new species, they were found in different microhabitats (larger streams and small rivers for S. lisu sp. nov., deep puddles or slow-flowing pools of streams for Zhangixalus cf. puerensis , and Rana suchinae ; Fig. 12C View FIGURE 12 ).