Montane endemism and cryptic diversity in Sulawesi: A new species of flying frog with derived breeding traits

We describe a new species of flying frog distinguished by morphological, genetic, acoustic, and reproductive characters. The new species is endemic to a high-elevation lake in the Mekongga Mountains, Southeast Sulawesi. Although phylogenetically allied to Rhacophorus boeadii, with minimal genetic divergence, the new species exhibits a derived reproductive mode characterized by egg deposition in an irregular gel matrix, lacking both foam structure and oviposition substrate specificity. The deposition of a cohesive gel matrix represents an oviposition strategy previously undocumented among Sulawesi Rhacophorus. This distinct reproductive mode may reflect ecological adaptation to ephemeral aquatic habitats and suggests a transitional or derived state within the genus. The discovery of the new species reveals further unstudied lineage diversification within Sulawesi’s montane amphibian fauna, and underscores the urgency of targeted surveys in montane regions increasingly threatened by anthropogenic pressures. Our findings highlight the importance of integrative approaches in uncovering cryptic diversity and refining our understanding of reproductive evolution within Rhacophoridae.