A new species of green tree frog of the genus Gracixalus (Anura: Rhacophoridae) from the evergreen forest of Northeast India

Abstract

We describe a new species of rhacophorid frog of the genus Gracixalus from northeast India based on molecular, morphological and acoustic evidence. The new species, formally described herein as Gracixalus patkaiensis sp. nov., is morphologically distinct from other congeners by a suite of morphological characters such as snout-vent length 23.6–26.5 mm in adult males; green dorsum with irregular brown spots; dorsal skin shagreened with numerous spinules; snout shape nearly acuminate in dorsal and ventral view; a prominent dark streak along the cranial margins; white reticulations along lateral side and ventrum distinct in life. Genetically, the new taxon is found to differ from all the recognized Gracixalus species by 4–14.8% divergence in the 16S mitochondrial gene. The discovery confirms the presence of genus Gracixalus from the Indian state of Arunachal Pradesh underlines the importance of biological exploration even in well-known protected areas of India.