Gracixalus weii, Liu & Peng & Wang & Feng & Shen & Li & Chen & Su & Tang, 2025

Liu, Jing, Peng, Cai-Chun, Wang, Bin, Feng, Chao-Bo, Shen, Tuo, Li, Shi-Ze, Chen, Ji-Jun, Su, Hai-Jun & Tang, Xiu-Jun, 2025, A new species of Gracixalus (Amphibia, Anura, Rhacophoridae) from Guizhou Province, China, Zoosystematics and Evolution 101 (1), pp. 405-417 : 405-417

Gracixalus weii sp. nov.

Holotype.

• MT LS 20240518008 adult male, collected by Jing Liu on 18 May 2024 in Leishan County (26.3733 ° N, 108.1967 ° E; elevation 1570 m a. s. l.), Guizhou Province, China.

Paratypes.

• One male MT LS 20230805003 was collected by Chaobo Feng on 5 August 2023 • two females, MT LS 20240518009 and MT LS 20240518010 , were collected by Jing Liu on 18 May 2024 • and three males, MT LS 20240517001 , MT LS 20240517002 , and MT LS 20240517003 , were collected by Caichun Peng on 18 May 2024 . All of the paratypes were collected from the same place as the holotype.

Description of holotype.

Adult male (Figs 4 , 5 ) of moderate body size, SVL 31.4 mm. The head width was larger than the head length (HDW: HDL = 1.08); the triangular snout showed a pointed appearance in the dorsal view, rounded in the profile, and projecting beyond the margin of the lower jaw; the canthus rostralis was distinct and rounded; the loreal region was oblique and concave; nostrils were oval and significantly protuberant and were closer to the tip of the snout than to the eye; the eyes were large with horizontal pupils; the eye diameter was 0.68 times that of snout length; the distinct tympanum was 0.69 times the eye diameter; the supratympanic fold was distinct, extending from the posterior corner of eye to above the insertion of the arm; no vomerine teeth were observed; the tongue was deeply notched behind.

The forelimbs were robust (LW / SVL = 0.08); the lower arm and hand beyond one-second of body length (LAL / SVL = 0.51); fingers were dorsoventrally compressed, with webbing rudimentary but with narrow lateral fringes on the outer edge of all fingers, relative finger lengths were ordered as I <II <IV <III; the tips of all fingers showed well-developed disks with horizontal circummarginal grooves; markedly elevated, prominent, and rounded subarticular tubercles were found on the fingers (one on fingers I and II, and two on fingers III and IV); supernumerary tubercles were present; the prepollex was distinct, oval; a nuptial pad was observed on the dorsolateral surface of the first finger.

Hindlimbs were 1.5 times the SVL; the tibiotarsal articulation reached the mid-eye level when legs were stretched forward; the tibias were longer than the thigh length; heels overlapped when thighs were positioned at right angles to the body; toes were slender, relative lengths I <II <III <V <IV; tips of toes showed expanded discs with distinct transverse circummarginal grooves. Distinct, rounded subarticular tubercles were seen on the fingers (one on fingers I and II, two on fingers III and V, three on finger IV); webbing formula I (2), (2 ½) II (1 ⅔), (3) III (2), (3) IV (3), (2) V; the sole was smooth with small tubercles; the inner metatarsal tubercle was elongated, ellipsoid; the outer metatarsal tubercle and the inner tarsal fold were absent.

The skin on the dorsal surface of the head, dorsum, and dorsal surfaces of the limbs was rough and sparsely scattered with conical tubercles; the ventral surface of the bell and limbs was rough with small tubercles.

Coloration in life.

In life, the dorsal surface ranged from brown to beige, with an inversed Y-shaped dark brown marking from the interorbital region, bifurcating into two branches on the shoulder and extending posteriorly; the dorsal surface of the arm and limbs showed dark brown transverse bands; several large dark blotches were observed on the ventrolateral region of flanks; the ventral surface of the throat, chest, and forelimbs was flesh-colored with small dark specks; the belly had large white tubercles; the ventral surface of the hindlimbs was brown; the disks at the tips of the fingers and toes were a pale yellow.

Color in preservative.

The dorsal surface of the head, body, and limbs was brown; the Y-shaped marking and transverse bands were black; the ventral surface of the chest and belly faded to white, with a gray throat (Fig. 5 ).

Variation.

The measurements of all specimens are listed in Table 3 and Suppl. material 3. All specimens were very similar in morphology. However, the dorsum of MT LS 20240517002 was brown, with a dark brown inversed Y-shaped marking on the dorsum (Fig. 6 A ); in MT LS 20240518010 , the dorsum and dorsal surfaces of the limbs were chocolate (Fig. 6 B ).

Secondary sexual characters.

Adult females were found to be larger than adult males. The adult males showed a single subgular vocal sac. In breeding, the nuptial pad was present on the dorsal surface of the bases of the first finger.

Diagnosis.

Gracixalus weii sp. nov. was assigned to the genus Gracixalus based on molecular data and morphological characteristics. Morphologically, the new species presented an intercalary cartilage between the terminal and penultimate phalanges of digits. The tips of the digits expanded into large disks with circummarginal grooves, the vomerine teeth were absent, and the pupil was horizontal ( Delorme et al. 2005).

Gracixalus weii sp. nov. can be distinguished from other congeners by the following characteristics: (1) moderate body size (SVL 30.1–34.0 mm in males and 35.2–36.0 mm in females); (2) head width larger than head length; (3) distinct tympanum; (4) brown to beige dorsum, with an inversed Y-shaped dark brown marking; (5) rough skin of the dorsal and lateral surfaces of the head, body, and limbs, sparsely scattered with tubercles; (6) toes with moderately developed webbing, while finger webbing was rudimentary; (7) nuptial pads on base of finger I; (8) males had a single subgular vocal sac; (9) tibiotarsal articulation reaching the mid-eye when leg stretched forward; (10) heels overlapping when legs at right angle to body.

Morphological comparisons.

A summary of morphological comparisons is present in Suppl. material 1. Gracixalus weii sp. nov. appears to be most closely related to G. jinxiuensis but differs from it by having a relatively larger size, SVL 30.1–34.0 mm in adult males and 35.2–36.0 mm in adult females (vs. 24.2–26.3 mm in males, 28.0– 29.2 mm in females); head width larger than head length (vs. the length and width of the head are almost equal); sole of foot and palmar smooth with sparse small tubercles (vs. rough with dense large tubercles); heels overlapped when thighs are positioned at right angles to the body (vs. heels just meeting); tibiotarsal articulation reaching the level of mid-eye when leg stretched forward (vs. posterior angle of eye); Gracixalus weii sp. nov. differs from G. jinxiuensis by having significantly lower ratios of ED, IOD, and SL to SVL in males and having significantly higher ratios of HDL, IND, TYD, and TFL to SVL in males (all p-values <0.05; Table 3 ).

Gracixalus weii sp. nov. can be distinguished from G. ananjevae by having a smaller body size in females SVL 35.2–36.0 mm in adult females (vs. 43.4 mm), with distinctive conical tubercles on dorsum (vs. absent) and skin of throat granular (vs. plain); from G. carinensis by having distinctive conical tubercles on dorsum (vs. absent); from G. gracilipes by having bigger body size both in males and females (SVL 30.1–34.0 mm in males and 35.2–36.0 mm in females vs. 20.0–24.0 mm in males and 26.4–28.8 mm in females), distinctive conical tubercles present on dorsum (versus absent), dorsal surface brown (vs. greenish), tibiotarsal articulation reaching to mid-eye (vs. reaching to between eye and nostril) and throat granular (vs. smooth); from G. guangdongensis by having distinctive conical tubercles on dorsum (vs. absent), finger webbing rudimentary (vs. absent) and linea masculine absent (vs. present); from G. jinggangensis by having distinctive conical tubercles on dorsum (vs. absent) and nuptial pads present only on finger I (vs. nuptial pads present on fingers I and II); from G. lumarius by having a smaller body size in males (SVL 30.1–34.0 mm vs. 38.9–41.6 mm) and males with an internal vocal sac (vs. an external vocal sac); from G. medogensis by having a bigger body size in males (SVL 30.1–34.0 mm vs. 26.5 mm), having distinctive conical tubercles on dorsum (vs. absent) and linea masculine absent (vs. present); from G. nonggangensis by having a bigger body size in females (SVL 35.2–36.0 mm vs. 26.8–27.3 mm), having distinctive conical tubercles on dorsum (vs. absent), finger webbing rudimentary (vs. absent), nuptial pads present on finger I (vs. nuptial pads absent) and tibiotarsal articulation reaching to mid-eye (vs. reaching to tip of snout); from G. patkaiensis by having bigger body size in males (SVL 30.1–34.0 mm vs. 23.6–26.5 mm), finger webbing rudimentary (vs. absent), males with an internal vocal sac (vs. an external vocal sac) and tibiotarsal articulation reaching to mid-eye (vs. reaching to tip of snout); from G. quangi by having bigger body size both in males and females (SVL 30.1–34.0 mm in adult males and 35.2–36.0 mm in adult females vs. 21.0–24.0 mm in males and 26.8–27.3 mm in females), finger webbing rudimentary (vs. absent), males with an internal vocal sac (vs. an external vocal sac) and skin of throat granular (vs. absent); from G. quangi by having bigger body size in males (SVL 30.1–34.0 mm vs. 28.5 mm), skin of throat granular (vs. absent) and tibiotarsal articulation reaching to mid-eye (vs. reaching to snout); from G. sapaensis by having bigger body size in males (SVL 30.1–34.0 mm vs. 20.8–29.6 mm) and with distinctive conical tubercles on dorsum (vs. absent); from G. seesom by having bigger body size both in males and females (SVL 30.1–34.0 mm in males and 35.2–36.0 mm in females vs. 21.6–23.0 mm in males and 23.2–25.4 mm in females), with distinctive conical tubercles on dorsum (vs. absent), males with an internal vocal sac (vs. an external vocal sac) and tibiotarsal articulation reaching to mid-eye (vs. reaching between eye and nostril); from G. supercornutus by having bigger body size in males (SVL 30.1–34.0 mm vs. 22.0– 24.1 mm); from G. tianlinensis by having distinctive conical tubercles on dorsum (vs. absent), males with an internal vocal sac (vs. an external vocal sac) and nuptial pads present only on finger I (vs. nuptial pads present on fingers I and II); from G. trieng by having smaller body size in males (SVL 30.1–34.0 mm vs. 37.2–41.4 mm), finger webbing rudimentary (vs. absent) and males with an internal vocal sac (vs. an external vocal sac); from G. truongi by having smaller body size in females (SVL 35.2–36.0 mm vs. 37.6–39.3 mm), finger webbing rudimentary (vs. absent), having distinctive conical tubercles on dorsum (vs. absent) and tibiotarsal articulation reaching to mid-eye (vs. reaching between eye and nostril); from G. yunnanensis by males with an internal vocal sac (vs. an external vocal sac); freom G. ziegleri by tibiotarsal articulation reaching to mid-eye (vs. reaching tip of snout).

Distribution and habitats.

At present, Gracixalus weii sp. nov. is only found in Leigongshan Nature Reserve, Leishan County, Guizhou Province, China. The population inhabits the mountain forests at elevations between 1600 and 1800 m and is often found on bamboo near streams (Fig. 7 ). Boulenophrys leishanensis Li, Xu, Liu, Jiang, Wei & Wang, 2018 ; B. spinata Liu & Hu, 1973 ; Leptobrachella wulingensis Qian, Xia, Cao, Xiao & Yang, 2020 ; and Leptobrachium leishanensis Liu & Hu, 1973 were also found in the type locality of the new species. After investigation, we only heard the calls of Gracixalus in mid to late May, and no calls were heard in other seasons, so we speculate that the breeding season may be in mid to late May.

Etymology.

The specific epithet “ weii ” was given in honor of Professor Gang Wei from Guiyang University, in recognition of his contributions to the systematic studies and biodiversity conservation of amphibians in China.

Figures

Figure 4. Photos of the holotype MT LS 20240518008 of Gracixalus weii sp. nov. in life. A. Dorsal view; B. Ventral view; C. Dorsal view of hand; D. Ventral view of hand; E. Ventral view of foot. (Photo A – E by Shize Li).

Figure 5. Comparison of morphological characteristics between the holotype specimen of Gracixalus weii sp. nov. (MT LS 20240518008; A, C, E, G) and Gracixalus jinxiuensis (CIB 58795 (660386); B, D, F, H). A, B. Dorsal view; C, D. Ventral view of hand; E, F. Ventral view; G, H. Ventral view of foot. (Photo A – H by Jing Liu).

Figure 6. Color variation in Gracixalus weii sp. nov. A. Dorsolateral view of the male specimen MT LS 20240517002; B. Dorsolateral view of the male specimen MT LS 20240518010. (Photo A, B by Shize Li).

Figure 7. Habitat of Gracixalus weii sp. nov. in the type locality, Leishan County, Guizhou Province, China. (Photo by Jing Liu).