Paramesotriton wumengshanensis Luo & Zhou, 2025

Paramesotriton wumengshanensis Luo & Zhou sp. nov.

Figs 5 View Figure 5 , 6 View Figure 6 , Suppl. material 1

Chresonymy.

Paramesotriton sp 2 (DF): Luo et al. 2021 (Dafang, Guizhou, China); Paramesotriton longliensis (DF) : Luo et al. 2022 (Dafang County, Guizhou, China).

Holotype.

Adult male, GZNU 20180711 , collected by Tao Luo on 11 July 2018, in Yuchong Township , Dafang County, Guizhou Province, China, 27.44933332°N, 105.95403671°E, elevation 1137 m a. s. l. GoogleMaps

Paratypes.

Three adult males: GZNU 2018070903 , GZNU 2018070904 , and GZNU 2018070905 . Three adult females: GZNU 2018070901 , GZNU 2018070902 , and GZNU 20180709011 . The locality and date of all paratypes are same as holotype GoogleMaps .

Etymology.

The specific epithet wumengshanensis refers to the type locality, located within the Wumeng Mountains, Guizhou, China. The suggested English name is the Wumeng Mountains Warty Newt, and the Chinese name is Wū Mēng Shān Luǒ Yuán (乌蒙山瘰螈).

Diagnosis.

(1) large body size, TOL 95.5–123.6 mm in adult males, TOL 150.1–160.0 mm in adult females; (2) absence of distinct colored stripes on dorsolateral ridges, consistent with body coloration; (3) absence of vestigial gills and gill filaments; (4) external eyes normal, eye diameter 14–20 % of head length; (5) absence of colored spots on the tails of males, a single red-orange stripe from the posterior margin of the cloaca to the 4 / 5 parts of tail on ventral side; (6) rough skin, body warts rough and large, and longitudinal grooves distinct on the body flanks; (7) yellow spot below the posterior margin of the eye absent; (8) vomerine teeth distinct, middle part depressed outward, having a slightly wider and shallow groove at middle base of each choana, and a distinctly prominent bony plate is present posterior to the choana; (9) anterior end of the epibranchial bone of the hyoid apparatus is near T-shaped.

Description of the holotype.

Adult male, TOL 123.6 mm, SVL 72.6 mm. Measurements are presented in Suppl. material 1. Body relatively slender. Head flat, distinctly longer than wide (length / width = 1.4), distinct scent glands on side of head; knob-like (Fig. 6 D View Figure 6 ), with a fleshy protuberance present in the branchial region. Snout short; snout arris evident, truncated, extending beyond lower lip; snout length distinctly longer than eye diameter; nostrils short, close to snout tip; eyes large; labial fold developed, extending from lower eye to tip of snout; gular fold developed; glandular ridge on each side of the head, slightly developed; tongue short, elliptical, both lateral sides dissociated; one premaxilla with tiny teeth on the upper and lower jaws. Vomerine teeth distinct, Ʌ-shaped, middle part depressed outward; dentition slowly compressed from posterior to anterior-to-anterior margin meeting between two nares; having a slightly wider and shallow groove at middle base of each choana; a distinctly prominent bony plate is present posterior to the choana (Fig. 7 A View Figure 7 ). Anterior end of the epibranchial bone of the hyoid apparatus is near T-shaped, connected with the first and second ceratobranchials of the bone; ceratohyal knife-like, with the anterior two-thirds in cartilage, left and right unconnected (Fig. 7 D View Figure 7 ). Vertebral ridge developed, light tan, conspicuous, unintermittent, from occiput to tail. Forelimbs short, reaching to tip of snout when adpressed forward; hind limbs longer and sturdier than forelimbs; palm and sole overlap when adpressed forelimb backward and hind limb forward along body flank; without metacarpal or metatarsal tubercles; four fingers and five toes without webbing or fringe; relative finger length 1 <4 <2 <3; relative toe length 1 <5 <2 <4 <3. Tail relatively long; dorsal and ventral caudal fins evident, expanding on posterior half of tail; tail-tip rounded. Cloaca a large slit, swollen into a small mound, villous mastoid around cloaca, many pubes on gaps of cloaca. Skin rough, especially on the back of the body; many warts and granular glands on dorsal skin, dorsal surface of the limbs, and lateral sides of tail. Longitudinal flank grooves distinct on the body flanks, approximately 17 (Fig. 6 E View Figure 6 ). Ventral skin wrinkled, densely covered with small warts (Fig. 6 C, H View Figure 6 ).

Sexual dimorphism.

Apophysis of cloaca of the male large and low, and the counterpart of the female small and high (Fig. 5 C, F View Figure 5 ). Female cloaca small and oval without gland in inside and lack finger-like papillae on the cloacal wall.

Coloration.

In life, dorsal surface of body black-brown and light olive color. Head, body, and ventral surfaces of limbs dark brown overall with irregular reddish-orange markings. Absence of distinct colored stripes on dorsolateral ridges, consistent with body coloration. A single red-orange or tangerine yellow stripe extends from the posterior margin of cloaca to the 4 / 5 parts of the tail on the ventral side (Fig. 6 H View Figure 6 ). Finger and toe tips grayish brown. Color lightens in 75 % ethanol preservation.

Comparison.

The new species can be assigned to the P. caudopunctatus group on the basis of phylogeny and can be distinguished from other species within that group by the following morphological characteristics (Table 4 View Table 4 ).

Paramesotriton wumengshanensis sp. nov. differs from P. caudopunctatus and P. wulingensis by absence of colored spots on the tails of males and colored stripes on dorsolateral ridges (vs. presence of purplish red spots on the tails of males and three yellowish brown longitudinal stripes very distinct on dorsolateral ridges).

Paramesotriton wumengshanensis sp. nov. differs from P. malipoensis by absence of vestigial gills and gill filaments in adults (vs. presence), snout-vent length greater than tail length (vs. almost equal), and absence of distinct colored stripes on dorsolateral ridges, consistent with body coloration (vs. dorsolateral ridges scattered with distinctive orange-red or brownish-yellow spots).

Paramesotriton wumengshanensis sp. nov. differs from P. zhijinensis by absence of distinct colored stripes on dorsolateral ridges, consistent with body coloration (vs. two or three near-continuous yellow stripes on the dorsolateral ridge), yellow spot below the posterior margin of the eye absent (vs. present), absence of vestigial gills and gill filaments in adults (vs. neoteny is common with most adult specimens having vestigial gills and gill filaments), vomerine teeth distinct, middle protruding outward, dentition slowly compressed from posterior to anterior to anterior margin meeting between two nares, having a slightly wider and shallow groove at middle base of each choana, a distinctly prominent bony plate is present posterior to the choana (vs. vomerine teeth indistinct, middle compressed inward, dentition rapidly compressed from posterior to anterior to anterior margin no meeting between two nares, having a small, narrow, deep groove at middle base of each choana, and bony plate posterior to the choana is highly reduced and indistinct), and ceratohyal knife-like (vs. boat-shaped) (Fig. 7 A, B View Figure 7 ).

Paramesotriton wumengshanensis sp. nov. differs from P. longliensis by absence of distinct colored stripes on dorsolateral ridges, consistent with body coloration (vs. dorsolateral ridges scattered with distinctive yellow granules or two or three near-continuous yellow stripes on the dorsolateral ridge), yellow spot below the posterior margin of the eye absent (vs. present); vomerine teeth distinct, middle protruding outward, dentition slowly compressed from posterior to anterior to anterior margin meeting between two nares, having a slightly wider and shallow groove at middle base of each choana, a distinctly prominent bony plate is present posterior to the choana (vs. vomerine teeth indistinct, middle compressed inward, dentition rapidly compressed from posterior to anterior to anterior margin no meeting between two nares, having a small and narrow groove at middle base of each choana, and bony plate posterior to the choana is highly reduced and indistinct), and ceratohyal knife-like (vs. boat-shaped) (Fig. 7 A, C View Figure 7 ).

Paramesotriton wumengshanensis sp. nov. differs from P. maolanensis by rough skin and external eyes normal, eye diameter 14–20 % of head length (vs. smooth skin and external eyes largely reduced), distinct longitudinal flank grooves (vs. indistinct or absent), and vertebral ridge well-developed and consistent with body coloration (vs. vertebral ridge slightly bulged, yellow) (Fig. 8 View Figure 8 ), and anterior end of the epibranchial bone of the hyoid apparatus is near T-shaped (vs. Y-shaped).

Distribution and habitat ecology.

Currently, Paramesotriton wumengshanensis sp. nov. is found only in three deep-water pools in the type locality. This area has a mean annual temperature of approximately 20 ° C and receives about 1,800 mm of annual precipitation, with a humid subtropical monsoon climate. Surrounding the waterholes are bamboo forests and local crops, including rice, corn, and chili peppers. During a survey in July 2018, several other species were also recorded at the type locality, including Triplophysa wulongensis Chen, Sheraliev, Shu & Peng, 2021 ; Rhinogobius giurinus Rutter, 1897 ; Tylototriton kweichowensis Fang & Chang, 1932 ; Boulenophrys qianbeiensis (Su, Shi, Wu, Li, Yao, Wang & Li, 2020) ; Oreolalax rhodostigmatus Hu & Fei, 1979 (tadpoles); Hyla annectans (Jerdon, 1870) ; and Odorrana grahami (Boulenger, 1917) . The primary threat to the species comes from ongoing mineral development in the upper reaches of the rivers within its range, which has caused the water in the mainstem rivers to become discolored (blackened), thus restricting the species to deep pools on the riverbanks. Currently, there have been no reports of illegal human capture. However, more ecological and reproductive information on this species is still lacking.