Scutiger lisu, Wang & Yu & Che, 2025

Scutiger lisu sp. nov. Wang, Yu, and Che

( Figs 3 View FIGURE 3 , 6 View FIGURE 6 , 7 View FIGURE 7 , and 12; Table 2 View TABLE 2 )

Chresonyms: Scutiger gongshanensis Fan 2015: 27 , 111.

Holotype: KIZ 039265 , adult male, from the west side of the Dugong Tunnel , Dulongjiang Township, Gongshan County, Yunnan Province, China ( 98.46942ºE, 27.84864ºN, elevation 2899 m, GCJ02). Collected by Zhong-Bin Yu and Shao-Bing Hou on 27 October 2021 GoogleMaps .

Paratypes (nine adult males, five adult females, and two juvenile females): KIZ 038612 , adult male, collected from Dulong Valley , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.46400ºE, 27.84360ºN, elevation 2884 m, GCJ02) by Zhong-Bin Yu, Dong An, Tian-En Chen on 27 July, 2021 GoogleMaps ; KIZ 038614 , 038615 , adult males, collected from Dulong Valley , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.52700ºE, 27.79086ºN, 3081 m, GCJ02) by Zhong-Bin Yu, Dong An, Tian-En Chen on 27 July, 2021 GoogleMaps ; KIZ 039255 , adult female, from the Old Road between Dulongjiang and Gongshan , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.45624ºE, 27.80631ºN, 3158 m, GCJ02) GoogleMaps ; KIZ 039266 and 039277 , adult females, collected from near entrance of the Dulong tunnel , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.46942ºE, 27.84864ºN, 2899 m, GCJ02) by Zhong-Bin Yu and Shao-Bing Hou on 28 October, 2021 GoogleMaps ; KIZ 50811 , adult male, collected from near the entrance of Dulong Tunnel , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.50500ºE, 27.79553ºN, 3092 m, GCJ02) by Zhong-Bin Yu on 8 August, 2022 GoogleMaps ; KIZ 53571 , adult male, collected 18km from Gongshan along the Dugong Rd , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.45456ºE, 27.83731ºN, 2923 m, GCJ02) by Zhong-Bin Yu, Dong An, Tian-En Chen, and Xian-Kun Huang on 27 June 2023 GoogleMaps ; KIZ 59703 , adult male, GoogleMaps KIZ 59702 , juvenile female, collected from the Dulong Pass , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.46123ºE, 27.78683ºN, 3347 m, GCJ02) by Zhuo-Yu Lu, Xiang-Jin Liu, and Xian-Kun Huang on 26 August 2024 GoogleMaps ; KIZ 58559 , adult male, KIZ 58562 , juvenile, collected from Dulongjiang Shentian , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China (98.46171ºN, 27.78348ºE, 3356 m, GCJ02) by Zhuo-Yu Lu, Xiang-Jin Liu, and Xian-Kun Huang on 29 August 2024 ; KIZ 53593 , adult male, collected from Degong Rd , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.71755ºE, 28.0005ºN, 2520 m) by Zhuo-Yu Lu, Dong An, Tian-En Chen, and Xian-Kun Huang on 2 July, 2023 GoogleMaps ; KIZ 51837 , adult female, from the Dulongjiang side of the Dulong Tunnel , Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.46359ºE, 27.88400ºN, 2874 m, GCJ02) by Kai Wang, Zhuo-Yu Lu, Xian-Kun Huang, and Yi-Lin Zhang on 27 May, 2023 GoogleMaps ; KIZ 50797 , adult female, from Yaping Rd in Fugong County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China ( 98.79712ºE, 27.15891ºN, 2451 m, GCJ02) by Zhong-Bin Yu on 5 August, 2022. GoogleMaps

Etymology: The species name “ lisu ” is derived from the Chinese word 傈僳, which is the name of the main ethnic group across the range of the new species. We name the new species after the local ethnic group to honor the harmony between the local ethnic culture and nature ecosystem. The proposed Chinese name of the new species is 傈僳ÊẊḆ (pinyin: Li Su Chi Tu Chan), and the proposed English name is Lisu Lazy Toad.

Diagnosis: Scutiger lisu sp. nov. can be diagnosed from all congeners by a combination of the following morphological characters: (1) body size large, SVL 75.2–82.5mm; (2) forearm and hand length long, LFHL 51.7– 55.3% SVL; (3) posterior head long, PHL 48.8–53.4% HL; (4) inter-nare distance short, IND 18.6–21.1% HW; (5) snout short, SEL 33.4–35.3% HL; (6) eyes small, ED 21.0–24.9% HL; (5) single pair of pectoral glands and axillary glands present in males; (6) fine spines present on pectoral glands and peripheral margin of chin on ventral head only in males, not on axillary glands; (7) maxillary teeth absence; (8) tongue slightly notched; (9) nuptial pads present on first two fingers in males, covered with a few enlarged black spines; (10) distinctively raised tubercles scattered on third finger, dorsal and lateral forearms, and anterior brachium, but all without spinules; (11) smaller, raised tubercles present on dorsal eyelids and supralabial as well as posterior jaw; (12) vocal sacs absent; (13) supratympanic fold strongly developed, extend posterior of axillary; (14) toes only rudimentarily webbed, with feeble dermal fringes; (15) parietal head concave; (16) dorsum warty, with large, relatively flat tubercles, somewhat in dorsolateral rows; and (17) dorsal surface near uniform Grayish Horn Color (Color 268) to Hair Brown (Color 277), sometimes with faint light Drab (Color 19) dorsolateral stripes on body.

Comparisons: The new species is sympatric and previously confused with S. gongshanensis , but it can be differentiated from the latter by a much larger body size ( SVL 75.2–82.5mm vs. 45.8–57.7mm), the absence of maxillary teeth (vs. presence), absence of vocal sacs in males (vs. presence), as well as by having longer forearms and hands (FHL 51.7–55.3% SVL vs. 43.8–48.1%), longer posterior head (PHL 48.8–53.4% HL vs. 38.2–44.3%;), smaller eyes (ED 21.0–24.9% HL vs. 28.5–35.3%), shorter internarial distance (IN 18.6–21.1% HW vs. 25.0– 28.0%), and a distinct dorsal coloration (dorsal near uniform near uniform Grayish Horn Color (Color 268) to Hair Brown (Color 277), sometimes with faint light Drab (Color 19) dorsolateral stripes on body, no marking on dorsal limbs vs. background Clay Color [Color 18] with distinct Light Orange Yellow [Color 7] stripes and Dark Neutral Gray [Color 299] spotting, including limbs).

Scutiger lisu sp. nov. is phylogenetically most closely related to members of the S. boulengeri - S. mammatus complex on the Qinghai-Xizang Plateau, but the new species can be diagnosed from S. boulengeri complex (including S. boulengeri and S. bangdaensis Rao, Hui, Ma, and Zhu, 2022 , as well as the two synonyms of S. boulengeri , namely Cophophryne alticola Procter, 1922 and Aelurophryne tainingensis Liu, 1950 ) by having a much larger body size ( SVL > 75mm vs. < 67mm), the absence of spinules on the abdominal region and on the axillary glands in males (vs. presence), and by the absence of spines on dorsal tubercles on the body (vs. presence); and from both S. mammatus and S. maculatus ( Liu, 1950) by having much weaker webbings between toes (only rudimentarily webbed vs. half or two third webbed) and a different shape of tongue (slightly notched vs. rounded).

Scutiger lisu sp. nov. is also morphologically similar to S. muliensis , where both species have similar body size, no nuptial spines on axillary glands in breeding males, no maxillary teeth, and enlarged spines on nuptial pads on fingers in males. However, the new species can be diagnosed from S. muliensis by a differential webbing between toes (only feebly webbed vs. one third webbing) and less developed fringes on toes (vs. much better developed).

For species distributed closely along the Gaoligong Mountain and the adjacent Biluo Snow Mountain, the new species differs from S. biluoensis , S. meiliensis , S. tengchongensis by the absence of nuptial spines on axillary glands in breeding males (vs. presence). Furthermore, S. lisu sp. nov. differs from S. tengchongensis by having a much larger adult body size ( SVL > 75mm vs. < 40mm), a distinct skin texture (scattered round tubercles without spines vs. longitudinal rows of tubercles and conical shaped individual tubercles covered with small spines), and a distinct iris color and pattern (Whitish Lime Green [Color 111] with fine, thin, black reticulated stripes vs. Cinnamon Brown [Color 43] with radial speckles of Straw Yellow [Color 53]); from S. biluoensis by the absence of maxillary teeth (vs. presence); and from S. meiliensis by the presence of spinules on forearms (vs. absence) and by the absence of maxillary teeth (vs. presence).

For all remaining species of the genus, the new species differs from S. bhutanensis Delorme and Dubois, 2001 , S. chintingensis , S. ghunsa Khatiwada, Shu, Subedi, Wang, Ohler, Cannatella, Xie, and Jiang, 2019 , S. glandulatus , S. jiulongensis , S. liupanensis , S. nepalensis Dubois, 1974 , S. ningshanensis Fang, 1985 , S. nyingchiensis , S. pingwuensis Liu and Tian, 1978 , S. sikimmensis ( Blyth, 1855) , S. spinosus , S. tuberculatus , S. wanglangensis , S. wolong , and S. wuguanfui Jiang, Rao, Yuan, Wang, Li, Hou, Che, and Che, 2012 by the absence of nuptial spines on axillary glands in breeding males (vs. presence); from S. adungensis Dubois, 1979 by much weaker dermal fringes (feeble vs. much better developed) and by the absence of vocal sacs (vs. presence); from S. liupanensis , S. ningshanensis , S. nyingchiensis , S. sikkimensis , S. wanglangensis , S. wuguanfui by the presence of spinules on forearms and brachium (vs. absence); and from S. chintingensis and S. wolong by the absence of maxillary teeth (vs. presence).

Description of the holotype: Adult male, body large, SVL 79.0 mm; head large, dorsally compressed, width about equal to length, HW 104.5% HL; parietal region concave; snout short, round anteriorly, slightly projecting beyond jaw, SEL 34.4% HL; lateral supralabial convex posterior to nares; nares closer to snout than eyes, facing dorsolaterally, internarial distance short, IN 19.9% HW; loreal concave; canthus rostralis distinct; eye raised, ED 24.7% HL, DEW 25.2% HL; iris ellipse shaped, vertically oriented; scattered small tubercles forming indistinct tympanic rim; frontal region flat, lateral temporal head distinctively convex, sandwiching single lateral concave groove in between; lateral outer edge of convex temporal forming supratympanic folds, strongly developed.

Limbs sturdy; forearm muscular, thick toward elbows, FAW 14.6 mm; forearm and hand long, FAL 51.7% SVL; fingers relative thick, free of webbing, tips slightly swollen, finger length I<II<IV<III; four longitudinal rows of distinct, raised nuptial spines present on each of first two fingers; inner metacarpal tubercle much larger than outer, not connected, inner one bean shaped; subdigital tubercles indistinct. Hindlimb muscular, strong, relatively short, heels not meeting anteriorly when adpressed, reaching only slightly over shoulder, HLL 139.4% SVL, FEM 40.1% SVL, TFL 63.6% SVL, TIB 35.7% SVL; foot slightly longer than tibia, FL 123.4% TIB; toe tips slightly swollen, toe length I<II <III < V <IV; dermal fringes visible but weak, toes with rudimentary webbing toward proximal ends, webbing formula I2– 21/2 II2–3 + III3–4 - IV4– 21/2 V; subdigital and subarticular tubercles absent on foot, subdigital ridges present; inner metatarsal tubercle distinct, oval shaped, about same length as first toe, outer metacarpal tubercle absent.

Dorsal skins of head, body, and limbs warty; fine tubercles with distinct black spinules present on supralabial and dorsal eyelids; lateral head posterior of eyes to tympanum concealed, covered with small to medium sized, raised tubercles; dorsal tubercles on dorsum much enlarged, flat; dorsal and lateral forelimbs scattered with distinct, raised tubercles; skin of hindlimbs smoother, with fewer, smaller, flat tubercles. Areas near cloaca with few flat tubercles.

Ventrally, fine spines present along peripheral edge of ventral lower lip, forming a distinct patch on mental projecting posteriorly; single pair of pectoral glands present on chest, covered with fine spines, somewhat elongated posterolaterally, forming a “/ \” shape, with anterior end close to the transverse line between jaw joints; single pair of axillary gland present, but no nuptial spines; ventrolateral surface body rougher than medial part.

Coloration: In life, the background coloration of dorsal and lateral surfaces of the head and body are nearly uniform Natal Brown (Color 49), slightly lighter on hindlimbs; a single Drab (Color 19) triangular pattern is present on snout, with its tip pointing anteriorly and base extending across the forehead and reaching eyes dorsally on both sides. Irises are Whitish Lime Green (Color 111) with fine, thin, black reticulated stripes. Two light Drab (Color 19) parallel lateral stripes are present on each side of the vertebrate from the temporal head to the area anterior of groin, one dorsally close to the vertebrate while the other is more lateral and continuous from the supratympanic fold. Small, raised tubercles on the supralabial, lateral head, forelimbs, and finger III and IV are offwhite. The dorsal surfaces of the first two fingers are Light Flesh Color (Color 250), which are covered with black nuptial spines. The ventral surfaces of the head and chest are Dark Lavender (Color 203) to Medium Fawn (Color 257), whereas the abdomen is uniform Cinnamon (Color 255). The ventral surface of forelimbs and hindlimbs are Medium Fawn (Color 257) with somewhat dirty marble pattern of Cinnamon (Color 255), particularly ventral thighs and crusts. Ventral surfaces of first two fingers, first three toes, tips of all fingers and toes, metacarpal tubercles, and metatarsal tubercles are Light Flesh Color (Color 250), and the ventral surfaces of the remaining fingers and toes are transitional colored from Cinnamon (Color 255) proximally to Light Flesh Color (Color 250) distally.

After preservation, the background dorsal coloration fades into Light Neutral Gray (Color 297). The lighter triangular pattern on the snout becomes Pale Neutral Gray (Color 296). The ventral body and limbs become uniform Pale Buff (Color 1), except the tip of fingers and toes, which become Pale Pinkish Buff (Color 3).

Variation: In addition to the obvious sexual dimorphic characters such as the absence of nuptial spines/spinules and presence of vocal sacs in females, males have much thicker and stronger arms ( FAW 17.2–18.2% FAL vs. 23.4–33.0%).

Among the male specimens, only one other specimen has black nuptial spines on pectoral glands ( KIZ 58559), where majority of the male paratypes have only rough residuals bases of nuptial spines on pectoral glands ( KIZ 038612, 038614, 53571, and 59703), and two paratypes ( KIZ 53593 and 50811) have completely smooth chest showing only vague signs for pectoral glands. For nuptial spines on the first two fingers, only the holotype has completely developed nuptial spines (indicated by a continuous black keratin layer covering all individual spines on each finger), where nuptial spines on all remaining males are either undeveloped (i.e. spine bases without any black keratin layer; KIZ 53571) or still under development (i.e. spine bases showing black keratin layer on the tips, but not continuous and covering entire dorsal finger; all remaining male paratypes).

Among females, one individual is gravid ( KIZ 50797), showing distinctively swollen abdomen, and one specimen ( KIZ 039277) has distinctively more slender and narrow body. Webbing are consistent among all examined specimens, with no sexual dimorphism observed.

Natural history and conservation: The new species inhabit alpine coniferous forest and adjacent streams and small rivers ( Fig. 12 View FIGURE 12 , A and B). Some males were in the middle of breeding conditions (i.e. with a distinct, black keratin layer on the nuptial spines on fingers and axillary glands) while others were not in late October, which suggest late October maybe toward the end of its breeding season. Scutiger lisu sp. nov. is sympatric with Rana shuchinae , Zhangixalus puerensis , and the other new species of Scutiger described below (Sp. 2). Currently, it is known from the type locality on the Gaoligong Mountain in Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province only ( Fig. 1 View FIGURE 1 ), but it may be found further southward along the Gaoligong Mountain Range and on the western slope of the mountain in Kachin State, Myanmar. Given the lack of distribution and population data of the new species, we assess Data Deficiency (DD) for its conservation status.