New insights into the distribution, larval morphology, and genetic diversity of the endangered toad, Ophryophryne gerti (Amphibia, Anura, Megophryidae), in Vietnam
Ophryophryne gerti, an endangered toad endemic to the Langbian Plateau, Vietnam, has been known only from a restricted range in Bidoup Nui Ba and Chu Yang Sin National Parks. The conservation and sustainability of the species require knowledge of its true distribution, life history, and genetic diversity. During field surveys from July 2022 to September 2023 on the Di Linh Plateau, the southernmost extent of the Truong Son Range, adult and tadpole specimens of O. gerti were collected. A 940 bp fragment of the mitochondrial 12S rRNA–16S rRNA region was sequenced for phylogenetic and population genetic analyses. Our findings extend the species’ known range approximately 66 km southward, documenting its presence at lower elevations (500–2000 m). Tadpoles of O. gerti are characterized by an oval, depressed body; dorsolateral eyes; sinistral spiracle; pointed tail tip; and keratodont-free oral disc with serrated jaw sheaths. Phylogenetic analyses confirmed that the newly collected Di Linh specimens belong to O. gerti, which is closely related to O. synoria. Ten haplotypes were detected across populations, with Di Linh showing higher haplotype diversity (Hd = 0.993) but slightly lower nucleotide diversity (π = 0.00465) than Bidoup–Chu Yang Sin (Hd = 0.791; π = 0.00485). Both genetic indices and neutrality tests revealed that populations of this species are threatened in the wild, including Di Linh and well-protected areas such as Bidoup–Nui Ba and Chu Yang Sin National Parks. The Di Linh populations carried excess rare variation or low-frequency polymorphisms due to habitat fragmentation. These results highlight the Di Linh Plateau as an important conservation unit for O. gerti and emphasize the need to protect fragmented forest habitats to preserve the species’ genetic diversity and adaptive potential.
Found an error? Please report to login@optimap.science.