“Finding these tiny frogs in bamboo thickets, from where they make whistling calls, is not easy. Upon eventually locating one, we were amazed by the frog’s completely translucent body and externally visible blue bones and green blood. I had not seen such a frog anywhere in India, in over three decades of my work on Indian amphibians,” SD Biju said.

Out of over 420 species of frogs home to India, Patkai green tree frog is the only one known to show this characteristic. The occurrence of turquoise bones and green blood is also globally rare. The study was undertaken as part of a work by one of the students of Biju, Tage Tago’s PhD research on Amphibians of Arunachal Pradesh.

Meanwhile, during the field surveys in Arunachal Pradesh, the team also discovered two new populations of another species, the Medog small tree frog. This is scientifically known as Gracixalus medogensis. This species was originally described from the Medog region in Tibet, China, in 1984 and knowledge about it remained limited.