The Brown Blotched Bengal Tree Frog, a new species
Six herpetologists from Assam, West Bengal and Malaysia have recorded a new species of tree frog that had eluded the world of science despite thriving in residential areas. Their study establishing the mid-sized tree frog as the 26th species under the genus Polypedates has been published in the latest edition of Zootaxa, a peer-reviewed scientific mega journal for animal taxonomists. Polypedates is a genus of tree frog found throughout South and Southeast Asia.
The new species has been named Brown Blotched Bengal Tree Frog (Polypedates bengalensis). The name is derived from a series of six to nine dark brown blotches that extend laterally from behind the frog’s eye to the vent. The frog’s body colour is yellowish-brown to greenish-brown. “This frog is a classic case of an amphibian being elusive while in plain human sight for ages. Specimens of this frog were not discovered from deep jungles but from residential areas in two districts of West Bengal,” Guwahati-based herpetologist Jayaditya Purkayastha, who runs the Help Earth NGO, told The Hindu. He is one of the six authors of the study.
The others are Madhurima Das from Assam, Kingshuk Mondal, Shibajee Mitra, and Anirban Chaudhuri from West Bengal and Universiti Malaysia Sarawak teacher Indraneil Das. What triggered the study was a photograph of the frog Mr. Mitra had sent Mr. Purkayastha via social media in the winter of 2016 for identification. The photo was from a residential area in Badu, North 24 Parganas district of West Bengal. “Through an initial literature review, it became evident that this interesting find may be new to science,” Mr. Purkayastha said. The frog was virtually forgotten until Mr. Mondal found more specimens from Khordanahala in South 24 Parganas district in mid-2018.
Mr. Chaudhuri coordinated the initiative of studying the new species in Kolkata. After all the measurements – the males varied from 47.9-53.6 mm in size and a single female was 72 mm – and other data collections were done, the herpetologists concluded that the frog belonged to the genus Polypedates. A genetic identity investigation by Ms. Das established the frog as a new species in this genus while the Malaysia-based Mr. Das, an authority on herpetofauna in Asia, took care of the team’s data limitations. The male frogs were seen perched on vegetation, including bamboo, banana and taro leaves, and were calling from a height of 1.2-1.8 m above ground, over stagnant waters bodies that were mostly rainwater pools.