Deep within the eastern slopes of the Western Ghats, a little discovery marked a paradigm shift in the scientific community, when a team of scientists found a purple frog species belonging to the Sooglossidae family.
While the earlier purple frog (Nasikabatrachus sahyadrensis) discovery happened in 2003 on the western slopes of the Western Ghats that receive heavy rainfall, the latest species of the family, Nasikabatrachus Bhupathi, was discovered from the rain shadow region called Watrap in Tamil Nadu in August. Though these frogs are restricted to the Seychelles archipelago, the discovery has laid bare the truth behind the Gondwanaland hypothesis about the Indian subcontinent being part of the ancient landmass of Gondwana before splitting from Seychelles 65 million years ago. And when the totally different looking amphibian—pig-like nose and the unusual hue—was found, everything got ‘curiouser and curiouser’.
Karthikeyan Vasudevan, a scientist from the Centre for Cellular and Molecular Biology in Hyderabad, who was part of the discovery team, recounts the incident that led to finding N Bhupathi—named after herpetologist Dr Bhupathy Subramaniam who died during a field research in 2014.
“My colleague S Jegath Janani claimed to have knowledge about a purple-looking frog spotted by people in tapioca gardens where it came to feed on the worms that affect the tapioca plants. She thought that it could be another species altogether. Her father owned a small patch of land near a forest close to the Western Ghats,” says the 44-year-old scientist. “So, Janani began her search some 80 metres from the MSL (mean sea level). The first challenge was to make sure that it was a different species from the one that inhabited the western slopes.”
So a specimen was isolated with tissues from it. “From there began a whole barrage of investigation with a micro CT scan of the animal being done, which ultimately proved that there were a lot of differences in their bone structure. Eventually, the team, which also included Elizabeth Prendini, Sushil Kumar Dutta and Ramesh K Aggarwal, made a full description of the animal.”
The specimen used to record the first description of the animal rests at the Zoological Survey of India in Kolkata, while the findings were published in the journal hosted by the Society for Conservation and Study of Amphibians based at the Museum of Natural History in Paris.
Karthikeyan reveals that the timing of events that led to the appearance of the two species roughly matches the timing of the beginning of monsoon in that region.
“The ancestors of the two species might have survived the area of this single mountain, but a shrunk in the rains might have restricted one to the eastern slopes and another to the western slopes, prompting them to occupy areas where they can breed and survive through million years,” he adds.
What intrigues the scientist about the new find is its life history. “N Bhupathi stays underground for the most time, coming out only for a few days to breed. How does it breathe inside the soil? And when there is no evidence of an ear how does it perceive sound?” he wonders. They are yet to find answers to these questions.
Regarding the discovery,he believes this is just the beginning. “It’s like giving a name to a child. We have to nurture the child, understand its life and habitat, and help it grow,” he says.
Purple frog
They have been independently evolving for 130 million years. Very little is known about their life underground or their distributional range. They are considered endangered. Some of the threats reported include consumption of the tadpoles by an indigenous community, construction of check dams to control water flow, which submerges their breeding sites and habitats.