Paramesotriton chongqingensis, Ma & Li & Yang & Wan & Ma & Shi & Wang, 2025

Ma, Qi, Li, Shi-Ze, Yang, Xiao, Wan, Li-Peng, Ma, Cheng-Cheng, Shi, Sheng-Chao & Wang, Zhi-Jian, 2025, Morphological and molecular evidence reveal a new species of the genus Paramesotriton (Caudata, Salamandridae) from Chongqing, China, Zoosystematics and Evolution 101 (4), pp. 2207-2220 : 2207-2220

publication ID	https://doi.org/10.3897/zse.101.168621
publication LSID	lsid:zoobank.org:pub:3030B073-4214-43A5-8540-50E527AA2B09
DOI	https://doi.org/10.5281/zenodo.17635433
persistent identifier	https://treatment.plazi.org/id/88B2B41C-D3E7-56DD-9646-569683B81AAE
treatment provided by	Zoosystematics and Evolution by Pensoft
scientific name	Paramesotriton chongqingensis
status	sp. nov.

Treatment

Paramesotriton chongqingensis sp. nov.

Type material.

Holotype: CMNH 1662 View Materials , adult male, collected from Ditang Township , Pengshui Miao and Tujia Autonomous County, Chongqing Municipality, China ( 29.61°N, 108.19°E; 718 m elevation) by Qi Ma on 30 June 2025 GoogleMaps .

Paratypes: CMNH 1575 ( female) collected by Qi Ma, Lipeng Wan on 18 May 2023 at the same locality as the holotype GoogleMaps ; CMNH 1658 , CMNH 1659 , CMNH 1660 ( males), and CMNH 1661 ( female), all collected at the same locality and date as the holotype GoogleMaps .

Etymology.

The specific epithet “chongqingensis” is named after the type locality, Chongqing, China. We suggest the English common name “ Chongqing Warty Newt” and the Chinese common name “ 重庆瘰螈 ” (Chóng qìng luǒ yuán).

Diagnosis.

The new species can be distinguished from its congeners by the following combination of morphological characteristics: (1) rough skin; (2) coloration of the vertebral ridge similar to, or slightly lighter than, the body coloration; (3) presence of horn-like projections posterodorsally on the head; (4) ventral surface of throat and body black with irregular orange-red or orange-yellow spots or streaks; (5) absence of vestigial gills and gill filaments in adults; (6) tail tip in a bluntly rounded tip; (7) absence of spotting on cheek, lateral sides of dorsum, lateral sides of tail, base of limbs; (8) forelimbs relatively long, when stretched forward along body their fingertips extend beyond the anterior corner of the eye; when forelimbs and hind limbs adpressed, palm and tarsus overlap; (9) both males and females possess yellow-white caudal stripes; ventral orange-red stripe extends from cloaca to tail tip or covers only proximal part near cloaca, disappearing at approximately 1 / 8 of tail length.

Description of the holotype.

The adult male specimen is well-preserved. SVL 77.2 mm, TAL 56.5 mm, for further measurements see Table 1 View Table 1 . Body relatively slender; head slightly flattened with a horn-like projection present on the posterior dorsal side of the head; head length exceeding head width ( HL / HW = 1.31); snout length greater than eye diameter ( SL / ED = 2.65); snout truncate in dorsal and lateral views, projecting beyond lower lip; canthus rostralis distinct; nostrils positioned anteriorly on lateral snout margins; rictus extending to lower corner of the eye; labial folds well-developed; upper and lower jaws bearing small teeth; vomerine teeth arranged in a “ ∧ ” shape; tongue elliptical, adhering to mouth floor with anterior and lateral margins not free or slightly free.

Limb lengths subequal; hindlimbs slightly more robust than forelimbs; forelimbs relatively long, finger tips extending beyond anterior corner of eye when adpressed anteriorly along body; palm and tarsus overlapping when forelimbs and hindlimbs adpressed against body; lateral fringes and webbing absent on fingers and toes; four fingers, five toes, relative finger lengths I <IV <II <III; relative toe lengths I <V <II <IV <III; tail length shorter than snout-vent length ( TAL / SVL = 0.69), base cylindrical, gradually becoming laterally compressed distally with bluntly rounded tip; skin rough; vertebral ridge prominent, dorsal surfaces of trunk, tail, and limbs bearing scattered tubercles and granular glands of varying sizes; ventrolateral skin rough with small tubercles; cloaca region swollen with transverse wrinkles

Color of holotype in life. Dorsal and lateral color of head, body, limbs, and tail tawny yellow. Vertebral ridges concolorous or slightly lighter. Ventral surfaces of gular region and body black with irregular orange-red or orange-yellow spots / streaks. Orange-red blotch anterior to cloaca. Orange-red stripe from cloacal posterior margin along ventral tail surface (proximal 1 / 8). Distinct yellow-white band laterally from tail base to tip (Fig. 3 View Figure 3 ).

Color of holotype in preservative. Dorsal and lateral coloration of head, trunk, limbs, and tail unchanged or slightly faded; ventral markings show fading: orange-red spots on gular and body venter, orange-red blotch anterior to cloacal opening, and orange-red stripe on ventral tail surface all faded to yellow or cream-yellow (Fig. 4 View Figure 4 ).

Variation.

Linear measurements summarized in Table 1 View Table 1 . Paratypes morphologically similar to holotype; adult dorsum tawny or dark brown; ventral pattern variable: irregular orange-red spots on venter or connected forming orange-red / orange-yellow streaks; orange-red stripe from cloacal posterior margin confined to proximal tail (terminating at approximately posterior 1 / 8 or extending to tip); distinct or faint yellow-white tail band present (Fig. 5 View Figure 5 ).

Sexual dimorphism.

Male cloaca: swelling large and low; anal opening a longitudinal slit. Female cloaca: swelling small and high; anal opening small, elliptical (Fig. 6 View Figure 6 ).

Ecology and distribution.

Paramesotriton chongqingensis sp. nov. inhabits montane streams at 700–1000 m elevation; water cold, clear, slow-flowing; substrate with sand, leaf litter, rocks, aquatic plants. Co-occurrence with stream fishes and small aquatic invertebrates. Stream width 5–10 m; mostly shallow except scattered pools ( 2–3 m deep). Riparian zone densely vegetated (evergreen forest); stream unshaded. Diurnally concealed at bottom or edges of the stream (Fig. 7 View Figure 7 ).

Comparisons.

Paramesotriton chongqingensis sp. nov. is phylogenetically close to P. zhijinensis , P. maolanensis , P. longliensis and P. wumengshanensis , but differs in the following (Figs 8 View Figure 8 , 9 View Figure 9 ).

Paramesotriton chongqingensis sp. nov. differs from P. zhijinensis by lacking vestigial gill or gill filaments on each side behind the head in adults (vs. present); vomerine ridges form a wider angle, not curved (vs. narrower and curved).

P. chongqingensis sp. nov. differs from P. maolanensis in having rough skin and normally developed eyes (vs. smooth skin and reduced eyes in P. maolanensis ); ventral surfaces of the gular region and body black with clear and sparse distinct irregular orange-red or orange-yellow spots or streaks (vs. small dense yellow dots present along ventrolateral body).

Paramesotriton chongqingensis sp. nov. differs from P. longliensis in posterior tail region not pale purplish-red in males; both sexes having paired yellowish-white caudal stripes (vs. posterior tail pale purplish-red without markings in male); ventral fin fold on postcloacal tail orange-red, extending to tail tip or fading approximately at posterior one-eighth (vs. orange-red only on posterior half); tongue elliptical, adhering to mouth floor with anterior and lateral margins not free or slightly free (vs. tongue adhering to mouth floor with free lateral margins);; vomerine ridges forms an wider angle, not curved (vs. narrower and curved); dorsal skin distinctly rough (vs. comparatively smooth).

Paramesotriton chongqingensis sp. nov. differs from P. wumengshanensis in ventral surfaces of the gular region and body black with irregular orange-red or orange-yellow spots or streaks (vs. head, body, and ventral surfaces of limbs dark brown overall with irregular reddish-orange markings, which are typically larger); ventral orange-red stripe extends from cloaca to tail tip or covers only proximal part near cloaca, disappearing at approximately 1 / 8 of tail length (vs. 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. 9 View Figure 9 ).

Paramesotriton chongqingensis sp. nov. differs from P. hongkongensis , P. labiatus , and P. maolanensis in having rougher skin (vs. skin smooth). It differs from P. aurantius , P. chinensis , P. caudopunctatus , P. wulingensis , and P. hongkongensis by having the dorsal vertebral ridge coloration closely matching the body color or slightly brighter (vs. bright orange and continuous in P. aurantius ; brown or maroon in P. chinensis ; earth-yellow longitudinal stripes on vertebral ridge and dorsolateral ridges in P. caudopunctatus and P. wulingensis ; distinctly light-colored in P. hongkongensis ). P. chongqingensis sp. nov. differs from P. aurantius , P. caudopunctatus , P. chinensis , P. deloustali , P. fuzhongensis , P. guangxiensis , P. hongkongensis , P. labiatus , P. malipoensis , P. qixilingensis , P. wulingensis , P. yunwuensis , and P. zhijinensis by possessing paired horn-like projections posterodorsally on the head (vs. absent). It differs from P. caudopunctatus , P. wulingensis , P. deloustali , P. guangxiensis , and P. yunwuensis in having the chin and venter black, mottled with irregular orange-red or orange-yellow blotches or streaks (vs. pale venter with dark blotches in P. caudopunctatus and P. wulingensis ; large orange ventral blotches in P. deloustali , P. guangxiensis , and P. yunwuensis ). It differs from P. qixilingensis in having a bluntly rounded tail tip (vs. tail tapering distally). P. chongqingensis sp. nov. differs from P. aurantius , P. caudopunctatus , P. wulingensis , and P. malipoensis by lacking blotches on the cheeks, lateral dorsum, tail sides, and limb bases (vs. irregular yellow spots present in these areas in P. aurantius ; purple-red spots bordered with black on lateral tail surfaces and pale lower lateral tail surface with small black spots in P. caudopunctatus and P. wulingensis ; distinct small orange-red or yellowish-orange spots dorsolaterally in rows extending to mid-tail in P. malipoensis ). It differs from P. yunwuensis in having finger tips extending beyond the anterior corner of the eye when forelimbs are stretched forward along body (vs. barely reaching posterior eye margin).