Scientists have identified a previously unknown frog species in the seasonally flooded forests of the western Amazon, revealing more hidden biodiversity in one of the world’s richest ecosystems. Researchers named the species Adenomera varcena. The small frog closely resembles several of its relatives, but differences in its DNA, physical features, and mating call confirmed it as a separate species.
The discovery adds to a series of unusual species documented across the Amazon. Scientists recently identified an ancient plant thriving in flooded Amazon forests and a tiny Amazon fish with a previously unknown organ. The frog findings were published in the journal Ichthyology & Herpetology. The research team included Célio F. B. Haddad of São Paulo State University, or UNESP, and Thiago R. Carvalho of the Federal University of Minas Gerais, or UFMG.
Scientists use DNA and calls to identify new frog
The discovery followed field expeditions in the Upper Juruá River region of Acre state in western Brazil. Scientists surveyed forest fragments near the Moa and Crôa rivers, close to Cruzeiro do Sul.
Researchers used several types of evidence to determine that the frog represented a new species. They analyzed its DNA, recorded its mating calls, and studied its physical features. They also examined habitat data and compared the frogs with specimens held in scientific collections.
Scientists have discovered a new frog species in the seasonally flooded forests of the western Amazon.
Named Adenomera varcena, the frog was identified through its DNA, physical features and distinctive mating call, revealing more of the Amazon’s hidden biodiversity. pic.twitter.com/sROW0VOCe1
— Tom Marvolo Riddle (@tom_riddle2025) September 17, 2026
One visible feature helped distinguish A. varcena from related frogs. It lacks a dark spot on the underside of its forearm. Its mating call provided another clue. The frog produces a short call at a relatively slow rhythm, along with other acoustic features that distinguish it from close relatives.
The finding highlights cryptic diversity, in which separate species can appear nearly identical. Researchers also found evidence that several Adenomera lineages in the Amazon have yet to be formally described. Other research has revealed similarly overlooked diversity in the region, including the identification of a previously unknown giant anaconda species in the Amazon.
Flooded habitat makes discovery unusual
The name varcena refers to Amazonian floodplain forests, which become submerged during parts of the year. That habitat makes the discovery particularly notable. Adenomera frogs have generally been associated with dryland forests. The new species provides evidence that members of the genus also inhabit seasonally flooded forests.
Scientists do not yet know enough about the frog’s ecology and reproductive cycle to determine how environmental changes could affect it. Carvalho said changes in seasonal flooding linked to climate change could potentially influence its reproductive behavior. Researchers, however, do not yet know the extent of any effect.
Scientists are increasingly studying how climate change and habitat loss can reshape vulnerable animal populations, particularly species that depend on narrow environmental conditions.
Formal identification could aid conservation
The discovery also highlights the role of taxonomy in conservation as natural habitats disappear. Haddad said ecosystem destruction is occurring faster than scientists can formally document species. Undescribed animals may be left out of threatened-species lists and other conservation assessments. “Describing new species serves as a tool that aids in their protection,” Haddad said.
Formally recognizing species can, therefore, have practical conservation consequences, particularly for animals restricted to specific habitats. The project involved researchers from UFMG, UNESP, the University of São Paulo, the Federal University of Uberlândia, and the Pontifical Catholic University of Ecuador in Quito.
See all the latest news from Greece and the world at Greekreporter.com. Contact our newsroom to report an update or send your story, photos and videos. Follow GR on Google News and subscribe here to our daily email!
