Revision of bush frogs, Raorchestes and Philautus (Amphibia: Anura: Rhacophoridae) from the northeast Indian biodiversity hotspot with description of thirteen new species

Bush frogs currently in the genera Raorchestes and Philautus are poorly documented from northeast India when compared to the Western Ghats of southwestern India. They are morphologically cryptic, but variable in their acoustic repertoire and genetic divergence. We present a long-overdue revision of the bush frogs of northeast India by sampling 81 localities in eight Indian States (including nine type localities of known species) and by comparing historical (especially, type) material.

Using an integrative approach that combines levels of divergence in mitochondrial DNA, a nuclear-encoded gene and comparing morphological and bioacoustic data, we demonstrate the existence of 13 new species, which are formally described here. In addition, based on the evidence from molecular and morphological data we synonymise four previously described species from this region. We resolve the taxonomic identities of three other frog species found in northeast India.

After extensive survey across northeast India, we did not find a single specimen of the genus Philautus. The only species in this genus with ambiguous generic identity is P. dubius which requires further taxonomic investigation.