NEWS - Based on morphological and molecular evidence, the researchers report a new toad in Oreolalax Myers & Leviton, 1962, which is so far only known from Shuhe Township, Yanyuan County, southern Sichuan Province, China. Yanyuan toothed toad (Oreolalax yanyuanensis) improves our understanding of species diversity in the genus Oreolalax.
The new species is assigned to the genus Oreolalax based on the characteristics of prominent maxillary teeth, rough back, large spots, covered with oval black spots, vertical pupils, a rather wide and posteriorly grooved tongue, prominent femoral glands, and pectoral and axillary glands present in males.
At least 19 species of Oreolalax have been documented in southwest China and northern Vietnam. O. yanyuanensis occurs at elevations of 3000-3200 meters and can be distinguished from several other Oreolalax species below 3000 meters. The new species is genetically closest to O. rugosus, O. liangbeiensis and O. major. The morphology is also clearly different from the three in the proportion of measurements.
The new species can be distinguished from the other species by the medium body size (39.8-52.8 mm) in males, no tympanic membrane, 1/3 toe webbing, triangular pattern between the eyes, presence of spiny spots on the middle of the chest, presence of dark stripes on the legs and presence of various brown spots scattered on the abdomen.
The specific epithet “yanyuan” refers to the type locality in Yanyuan County, Sichuan Province. We propose the common name as “Yanyuan toothed toad” and the Chinese name as “Yan Yuan Chi Chan (盐源齿蟾)”.
O. yanyuanensis inhabits shrubs in subtropical mountain swamps and small mountain streams. The researchers estimated the breeding period in April or May based on the developmental stage of the tadpoles. Four sympatric amphibian species are Bombina maxima Boulenger 1905, Rana chaochiaoensis Liu 1946, Panophrys binchuanensis Ye & Fei 1995 and Nanorana sichuanensis Dubois 1987.
Most Oreolalax species are distributed in the eastern Hengduan Mountains and surrounding mountains in the Sichuan Basin at elevations of 700-3550 m. More than half of the Oreolalax species are listed as “threatened” by the IUCN due to habitat degradation, logging, tourism and invasive species. About 12 species are listed as “vulnerable, near threatened, endangered or critically endangered”.
In addition, some species are only recorded at type sites and habitats are not covered by any biodiversity conservation network, even with a high risk of extinction (O. puxiongensis). Furthermore, the unassessed O. longmenmontis has faced low populations and habitat loss. Status assessment is needed for these groups, especially O. yanyuanensis and O. weigoldi.
Original research
Hou YM, Zheng PY, Yu HQ, Wang B, Chen XH, Xie F (2024). A new toad of Oreolalax Myers & Leviton, 1962 (Anura, Megophryidae) from Sichuan Province, southwest China. ZooKeys 1212: 109-127, DOI:10.3897/zookeys.1212.122222
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