Field and genetic study identifies new Chinese horned toad in western Guangdong

A field and molecular study in western Guangdong described a new species of Chinese horned toad, Boulenophrys yangchunensis , and documented range extensions for two related species. The authors also recommended extinction-risk assessments for four taxa: B. acuta , B. yunkaiensis , B. gaolanensis and the newly described toad. The research centered on Guangdong Yangchun Ehuangzhang Provincial Nature Reserve, where five adult male toads were collected on 11 August 2023 at approximately 1,060 metres above sea level.

Six additional samples came from tail fins of tadpoles observed at the reserve; the tadpoles themselves were not collected. The five adults had snout–vent lengths of 27.6–28.7 mm. Preserved specimens were deposited at the Guangdong Polytechnic of Environmental Protection Engineering, the Museum of Biology at Sun Yat-sen University and the Herpetological Museum at the Chengdu Institute of Biology.

Researchers combined external measurements and examination of diagnostic features with phylogenetic analysis of partial mitochondrial 16S ribosomal RNA and cytochrome c oxidase 1 sequences. Maximum-likelihood and Bayesian analyses produced essentially identical tree topologies, while genetic distances were calculated from 16S data using an uncorrected p-distance model. The five adults formed a monophyletic lineage with a maximum-likelihood bootstrap value of 100 and a Bayesian posterior probability of 1.00.

This lineage was the sister group to B. acuta , with strong support of 97 and 1.00, respectively, and differed from it by a mean 16S p-distance of 6.5%. Morphological examination also distinguished the specimens from all recognized congeners, supporting their description as B. yangchunensis . Among the new species’ closest relatives, B. yangchunensis differs from B. acuta in having heels that just meet when the hindlimbs are folded, no vomerine ridge, and toes without webbing or lateral fringes.

Breeding males have nuptial pads bearing dense nuptial spines on the dorsal bases of the first two fingers, whereas B. acuta has weak pads without spines. Compared with B. gaolanensis , the new species has meeting rather than non-meeting heels, a sharpened rather than rounded snout in dorsal view, and visible nuptial pads and spines. B. yangchunensis is currently known only from Ehuangzhang Provincial Nature Reserve, where it inhabits flowing montane streams and nearby forest floor and leaf litter.

The surrounding habitat consists of evergreen broad-leaved forest mixed with bamboo groves at elevations of 900–1,100 metres. Male advertisement calls were heard from February to May, and calling males were observed on leaves 10–30 cm above the ground. These observations document the known locality and activity period but do not establish the species’ full distribution or population size.

Field and molecular evidence also extended the known distributions of B. acuta and B. yunkaiensis to Ehuangzhang. Tail-fin samples assigned to B. acuta clustered with reference specimens from Heishiding Nature Reserve and Mount Yunkai, while samples assigned to B. yunkaiensis clustered with Mount Yunkai reference samples. The new B. acuta locality is about 188 km in straight-line distance from its type locality, and the B. yunkaiensis locality is about 52 km from Mount Yunkai.

Using the IUCN Red List categories and criteria and the GeoCAT platform, the researchers recommended listing B. acuta as Endangered under criteria B1ab(iii) and B2ab(iii). Its extent of occurrence was estimated at 3,170 km² and its area of occupancy at 12 km², with records from three independent locations and an observed decline in habitat quality. The authors characterized this as a non-genuine downlisting from Critically Endangered because the new populations showed that its range had been underestimated.

It was a recommendation for reassessment rather than a final Red List decision. The authors recommended Critically Endangered status for B. yangchunensis , B. yunkaiensis and B. gaolanensis under specified geographic-range criteria. The new species was known from one location, with an area of occupancy of 4 km²; B. yunkaiensis was known from two locations and had an area of occupancy of 8 km²; and B. gaolanensis also had an area of occupancy of 8 km².

These recommendations could change if additional populations were found in adjacent potentially suitable habitat, but such occurrence was not established by the study.

Subject of Research: Taxonomic description and extinction-risk assessment of Chinese horned toads in western Guangdong

Article Title: A new species of Chinese horned toad ( Anura , Megophryidae , Boulenophrys ) from western Guangdong Province, China, with recommendations for extinction risk assessments for several related congeners

Article References: Zhao, Y.-Y., Lin, S.-S., Li, Y.-H., Lyu, Z.-T., Zheng, K., Zeng, Z.-C., Borzée, A., & Wang, J. (2025). A new species of Chinese horned toad (Anura, Megophryidae, Boulenophrys) from western Guangdong Province, China, with recommendations for extinction risk assessments for several related congeners. Herpetozoa, 38, 345-357. https://doi.org/10.3897/herpetozoa.38.e171400

Image Credits: AI Generated

DOI: 10.3897/herpetozoa.38.e171400

Keywords: Boulenophrys, new species, Chinese horned toad, Guangdong, field survey, molecular phylogenetics, range extension, IUCN Red List, extinction risk, amphibian conservation, species, Chinese