New frog species discovered in Amazonian flooded forests

Researchers have identified a new frog species, Adenomera varcena, in the flooded forests of the western Amazon in Acre, Brazil. The discovery occurred near the Moa and Crôa rivers in the Alto Juruá region during expeditions involving Brazilian and international scientists.

The identification is an example of cryptic diversity, where species appear nearly identical but are genetically distinct. To confirm the new species, scientists utilized DNA analysis, physical characteristics, mating call recordings, habitat data, and comparisons with preserved specimens. The findings were published on May 15 in the journal Ichthyology & Herpetology.

The name ‘varcena’ refers to the flooded Amazonian forests where the frog resides. This habitat preference is notable because members of the Adenomera genus are typically found in dry land forests, making this the first recorded instance of such a preference for the group. Physical distinctions include the absence of a dark spot on the underside of the forearm and a unique, slow-paced mating call.