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| Paramesotriton chongqingensis Q. Ma, Li, Yang, Wan, C.-C. Ma, Shi et Wang, 2025. |
Abstract
Based on morphological and molecular phylogenetic evidence, this study describes a new species of the salamandrid genus Paramesotriton discovered in Pengshui Miao and Tujia Autonomous County, Chongqing Municipality, China. The taxonomic status of this new species was established through integrated morphological characterization and multi-gene phylogenetic analysis (mitochondrial genes ND2 and Cytb, and nuclear gene POMC). The new species is primarily diagnosed by the following characteristics: presence of horn-like projections posterior to the head; black ground coloration on the throat and venter adorned with irregular orange-red blotches; bluntly rounded tail tip; and overlapping digits when the limbs are pressed along the body flank with the forelimb backward and the hind limb forward. Additional diagnostic characteristics include the absence of vestigial gills and gill filaments and lack of yellow spots on lateral sides of dorsum and tail. Molecular phylogenetic analyses place the new species within the P. caudopunctatus group (Clade B), forming a strongly supported sister group (BI = 0.91, ML = 74) to the combined clade comprising P. maolanensis, P. wumengshanensis and P. longliensis. The minimum genetic distance between the new species and its closest relative P. maolanensis reaches 0.78% (Cytb, p-distances), exceeding interspecific divergence observed among some congeners (e.g., 0.63% between P. maolanensis and P. longliensis), further supporting its distinct species status. This discovery further validates the persistence of cryptic diversity in the karst mountain regions of southwestern China, such as the Wuling Mountains. The new species has a restricted distribution and specialization to stream habitats at elevations of 700–1000 meters which render it is highly susceptible to threats from habitat fragmentation and illegal exploitation. It is recommended that this species should be categorized as “threatened” and that urgent conservation measures need to be implemented.
Key Words: cryptic species, Paramesotriton chongqingensis sp. nov., Southwestern China, Wuling Mountains
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| Holotype of Paramesotriton chongqingensis sp. nov. (CMNH1662) in life. A. Dorsal view; B. Lateral view; C. Ventral view. Photos by Qi Ma. |
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| Habitat of Paramesotriton chongqingensis at the type locality in Ditang Township, Pengshui Miao and Tujia Autonomous County, Chongqing, China. A. Habit; B. Ecological photo of specimen CMNH1575. Photos by Qi Ma. |
Paramesotriton chongqingensis sp. nov.
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.
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).
Qi Ma, Shi-Ze Li, Xiao Yang, Li-Peng Wan, Cheng-Cheng Ma, Sheng-Chao Shi and Zhi-Jian Wang. 2025. Morphological and Molecular Evidence reveal A New Species of the Genus Paramesotriton (Caudata, Salamandridae) from Chongqing, China. Zoosystematics and Evolution. 101(4): 2207-2220. DOI: doi.org/10.3897/zse.101.168621
