New bush frog species discovered from Western Ghats of Maharashtra

Raorchestes ghatei
(Photo Courtesy: JOTT, Image Credit: Anand D Padhye)

Amidst the ruckus raised by mining lobbies and real estate mafias against the implementation of the expert panel report on conserving the Western Ghats mountain ranges, researchers continue to discover species unknown to science from different parts of this biodiversity hot-spot. The latest in the line is Raorchestes ghatei, a new species of Bush Frog discovered from the Western Ghats in the state of Maharashtra.

According to a study published in the Journal of Threatened Taxa, the new frog species is very different from its closest relatives. Apart from the observable morphological differences, the sequencing study of the mRNA of the newly described frog confirms its identity as a distinct species of bush frogs. According to the research note, ‘molecular phylogeny based on 16S rRNA gene sequence suggests that the new species is genetically distinct and forms a monophyletic clade within Raorchestes, the genus of bush frogs’ to which it belongs.

Researchers came across this enigmatic species from different places in Satara and Pune districts of Maharashtra. They have christened it after Dr. H.V. Ghate known for his contributions to the herpetology of Western Ghats of Maharashtra. According to the researchers, the frog will be known as Ghate’s Shrub Frog.

Based on historical records, the researchers claim that the Ghate’s Shrub Frog is widely distributed in the Western Ghats of Maharashtra. It typically inhabits scrub patches and semi-evergreen forests. The species shows sexual dimorphism due to which males and females of the species look different. In fact, they are different in their behavior too, say the researchers. While the females prefer to hide under loose stones, males usually perch on shrubs and tree trunks up to 5 meters above the ground.

Unlike many other frogs, the new species does not have a free-swimming tadpole stage in its development.  Instead, it shows direct development – emerging as a morphological miniature of the adult from the egg. As per the study, Raorchestes ghatei usually lays egg in loose soil under stones.

Amphibian diversity in Western Ghats

Western Ghats is known for its rich amphibian diversity, the new discovery adds to human efforts to understand it. According to a theme paper on Amphibian diversity prepared by Western Ghats Ecology Expert Panel, India is home to 311 species of amphibians among which 161 are found in Western Ghats. According to the paper, at least 138 species of amphibian species are endemic to Western Ghats. However, much of this diversity was unknown to science until recently and is still getting unearthed. During the last ten years from 2003, at least 37 new species of frogs have been discovered from different parts of the Western Ghats.

According to the new study which described Raorchestes ghatei , though specific threat to the new frog species were difficult to identify, the habitat destruction due to human interference is a major threat to the endemic amphibian diversity in Western Ghats. “Even though no specific threats could be identified for the species, continuous deforestation in these areas leading to habitat fragmentation could be a threat to the species”, says the study. According to the researchers, tourism activities as well as setting up of wind farms are also leading to destruction of amphibian habitat in this area.

Anand D. Padhye and Anushree Jadhav of Department of Zoology, MES’s Abasaheb Garware College, Pune, Amit Sayyed of Wildlife Protection and Research Society, Satara and Neelesh Dahanukar from Indian institute of Science Education and Research, Pune have co-authored the study.