Dr. Aravind Madhyastha, Fellow, Suri Sehgal Centre for Biodiversity and Conservation, Ashoka Trust for Research in Ecology and Environment (ATREE), is a mollusc expert with a keen interest in freshwater and land snails, with a career encompassing ecology as well as conservation.

A member of IUCN’s Mollusc Specialist Group, his work on snails has led to collaborations with scientists and conservation bodies from around the world, identifying hitherto unknown freshwater snail and frog species in Karnataka, assessing their conservation status, and highlighting the critical need to preserve their habitats. An avid bird artist in his high school years, with several painting exhibitions to his credit, he now dabbles in macro and landscape photography.

In conversation with Ramya Coushik, Dr. Aravind Madhyastha talks about his fascinating journey from his hometown, Udupi, to a life courting snails.

1) How did you develop an interest in molluscs, and non-marine molluscs in particular?

In 1995, my father began researching molluscs, primarily freshwater species, when he collaborated with Professor Madhav Gadgil for a project on the biodiversity of the Western Ghats. I was part of the student contingent helping him with data collection and other tasks. He then had the opportunity to visit London’s Natural History Museum, to study the freshwater molluscs of the Western Ghats. On his return, he undertook several surveys across the Western Ghats in search of molluscs; I used to accompany him on his field trips for sampling. I had started birding with my father since I was nine years old; but suddenly, I was no longer looking up at trees for birds, but instead, down in streams, swamps, and fields for molluscs. This was a new experience.

Why non-marine molluscs? Compared to birds or mammals, barely a handful of researchers in India study non-marine molluscs, an elusive and interesting group. Also, their shape, form and sizes fascinate me. All of us have collected shells from the seashore and understand how diverse they are. Non-marine molluscs are also as attractive as their marine counterparts in the sheer variety in colour, shape, size and form. They form an important group economically, culturally and ecologically.

2) Your father, Dr. Ananthram Madhyastha, is an acclaimed zoology scholar. How much of a role did this play in shaping your interests and choice of career?

I owe my career path and accomplishments to my father. He used to take me bird-watching in and around Udupi during weekends. He used to ask me to identify birds using ‘Collin’s Hand-guide to the Birds of the Indian Subcontinent’. When I was older, he bought me a copy of ‘The Book of Indian Birds’ by Salim Ali. But sensing my interest in animals, he let me pursue it. During my school years—and even now—every parent in that region wanted their children to study either medicine or engineering. Thanks to my father, I had the choice to follow my passion.

Also, our house in Udupi was akin to a mini zoo and a wildlife hospital. My father used to contribute—and still does—articles to Kannada dailies about biodiversity, especially birds. All the injured birds and animals in the region used to end up as our guests. We have treated Masked Boobies, frigatebirds, Common Terns, Rosy Terns, Black Kites, barbets, a jackal, and many more, nurturing them back to health before releasing them. This early exposure too fostered my interest towards wildlife and nature.

3) Did growing up in Udupi play its part too?

Growing up in Udupi and spending winter and summer holidays in Malenadu (the Western Ghats), from where my mother hails, stoked my interest and my decision to eventually make a career studying nature. Together with my mother and two brothers, I used to visit my maternal grandmother in Kammaradi, a village in Thirthahalli Taluk in the heart of Malenadu, surrounded by forests and plantations. I used to spend a lot of time watching birds, observing plants and everything around. I distinctly remember the first time I sighted a Rufous Woodpecker and a Crematogaster Ant’s nest as a 12-year-old – it fascinated me to no end.

After completing my master’s degree from Mangalore University, I had the opportunity to join ATREE, one of India’s top think-tanks and research institutes. I had the privilege of working under Professor R. Uma Shaanker and Professor KN Ganeshaiah, both doyens in the fields of evolutionary biology, ecology and conservation. Together, they founded ATREE. I owe them my understanding of these fields and continue to collaborate with both on many projects.

4) While the role of snails as nutrient recyclers and important prey for birds, rodents and reptiles is known, some mollusc species are also considered invasive in agriculture. How do you view this dichotomy? Are there measures that can diminish or negate the losses on both sides?

There is no dichotomy as such. Only a few are agricultural pests in India, compared to some other regions of the world: to be precise, only half-a-dozen species cause damage to a certain extent to agricultural and horticultural crops. But the damage caused by snails and slugs is relatively less compared to insect pests. Also, one should adopt innovative approaches to manage snail pests – snails are rich in calcium, and after drying, can be used as feed for local fish and poultry. This can help control snail attacks on crops, provide much-needed protein and calcium for fish and poultry, and mitigate the threat these invasive snail species pose to our native snail species.

5) You have researched freshwater molluscs and amphibians extensively over the years. You are also presently leading a study on snails of the Western Ghats and Northeast India. Can you share a few highlights specific to molluscs from your years of field and lab research?

My research on molluscs and frogs led to the discovery of seven new species of snails and four species of frogs, all from the Western Ghats. Over the last two decades, this research has unearthed important aspects about Indian freshwater and land snail ecology and conservation needs. I would like to highlight a few.

The first is about the freshwater mollusc group, Cremnoconchus, commonly called Cliff Shell or Freshwater Periwinkle, which has relatives in the marine environment; all known species are found only in Karnataka and Maharashtra. They exist exclusively in and around waterfalls and nowhere else. Till date, nine species have been described – six from Karnataka and three from Maharashtra. All the six Karnataka species were described by my father Dr. Ananthram Madhyastha, Dr. David Reid from the Natural History Museum, London, and me. There are 12 more that are new to science; we will describe them soon. This diversity—what we call endemic radiation—is comparable to those in ancient lakes like Tanganyika and Victoria in eastern Africa, Sulawesi In Indonesia, or Baikal in eastern Siberia. All Cremnoconchus species are found only in one or two waterfalls. If there is any significant disturbance to the waterfalls, this species is sure to vanish from the face of the earth forever.

The second interesting aspect – our extensive field surveys, molecular analysis and modelling methods have shown that there may be around 800 to 2000 new species of non-marine molluscs in India. Particularly in the Western Ghats, we have 330 reported species. I expect that we can discover another 250 to 500 new species if one undertakes an extensive survey, especially in the high altitudes of the Western Ghats and the drier parts of the Karnataka, which have never been surveyed.

I am also collaborating with Professor Fred Naggs, an expert on South-Asian land molluscs from the Natural History Museum, London, in describing several undescribed species from India’s northeast region.

6) Who have been your mentors, shaping your thought processes and research?

My research—both in the lab as well as in the field—was shaped by my training with Dr. R. Uma Shaanker, Dr. KN Ganeshaiah, Professor Madhav Gadgil and Professor Amitab Joshi from Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR). I learnt the principles of field ecology, wet lab work and observation work during my summer internship as an undergraduate student with Professor Madhav Gadgil and Professor Amitab Joshi. I use these learnings in my research to this day. The experience also helped me see the big picture in terms of evolution. Though I presently do not conduct lab-based observations on molluscs, I do want to use molluscs as model organisms to find answers to certain evolutionary questions in the future.

7) You are known to use a range of modelling tools including harnessing Big Data in your research methodology. How has this eased or advanced research methodologies as against conventional research approaches? Give us some practical insights and examples.

I enjoy big data analysis, where we use huge amounts of data of over 50,000 records to decipher patterns at a large spatial scale (e.g., at a global scale) and a temporal scale (time-related, for e.g., over several years or decades) using various modelling approaches. Big data and data mining techniques help me understand patterns and processes in nature. I use a traditional statistical modelling approach to Geographical Information System or GIS, to decipher the pattern.

In the conventional approach, small data sets were used to look at the pattern in a small area or region using classical statistical approaches. Big data helps address larger issues such as climate change, biodiversity distribution patterns, its drivers etc. at larger scales, say at a global level.

I employ a modelling approach called ‘Ecological Niche Modelling’ or ‘Species Distribution Modelling’ to understand the species’ potential niche or possible distribution range using the data on climate, altitude and species distribution. These modelling approaches help understand their distribution on earth, potential areas at risk of attacks by invasive species, and the impact of climate change on the species in question.

I use this modelling approach to address some of the issues mentioned above for a host of taxa ranging from plants and birds to frogs and molluscs. These results will help policy makers and forest managers allocate resource more efficiently, and identify regions for the conservation and management of endemic species and/or invasive species. Our lab is among the best in niche modelling in the whole of South Asia.

8) There is nothing in the natural world that has stayed insulated from the effects of climate change. What have your studies revealed about its effects on molluscs and amphibians?

Our studies on the impact of climate change on molluscs and frogs show that endemic species such as the orange snail (Indrella ampulla) found in Kodagu and  purple frog (Nasikabatrachus sahyadrensis) are set to contract their distribution range i.e., they will lose suitable habitats in the future. On the other hand, invasive species such as the Giant African Land Snail (Lissachatina fulica) and the newly introduced slug to India, a caterpillar slug (Laevicaulis haroldii), are increasing their range. Also, modelling exercises have shown that many invasive molluscs can adapt to the changing climate. This has profound implications in terms of local biodiversity, economy, and human health.

Significantly, Giant African Land Snail is not only an agricultural pest, but also an intermediate host for several parasites including those that cause Eosinophilic Meningitis and Schistosomiasis, also known as snail fever, in humans and cattle.

9) How did these invasive snail species make their way into our ecosystem?

While several invasive species are introduced accidentally through trade, some like the Giant African Land Snail were deliberately introduced. This large snail was bought to India by William Benson, a pioneer in Indian malacology, in 1847, as a pet from Maldives. When he left India, he gave a pair of these to his friend and neighbour, who left these snails in his backyard in Chowringhee in Kolkata; it has since spread throughout India. Another potential source of the introduction of invasives is through aquarium trade – over half-a-dozen aquatic snails are traded in India. One must be careful and should not release them into nature, as they might eventually become invasive and have a significant impact not only on native biodiversity, but also on the economy of farmers.

10) We are currently suffering a global health crisis with the outbreak of a zoonotic virus – the Novel Coronavirus. Tell us a bit about how humans contract Eosinophilic Meningitis and Schistosomiasis from parasite hosts.

Eosinophilic Meningitis is caused by consuming raw or undercooked snails (freshwater and terrestrial), or other host species such as freshwater shrimps, frogs, or monitor lizards. Rat lungworm (Angiostrongyliasis) is a parasite that mostly lives in rats, and can infect snails and slugs when they come in contact with rat faeces. Humans can contract the disease if they consume infected snails and slugs. The Giant African Land Snail is a known carrier for rat lungworm. But we do not have any information beyond this. We are working to understand the extent to which these invasive giant snails harbour this parasite.

Schistosomiasis is a disease caused by parasitic flatworms. The larvae of schistosomes develop in snails and infect the urinary tracts or intestines of humans by penetrating the skin. Most snails such as Indoplanorbis, Lymnaea etc., which are carriers for Schistosomiasis, are found in polluted waters. People working in the fields in rural areas, and children playing in polluted rivers or lakes, are most vulnerable.

While good health and hygiene practices among the rural poor in tropical countries, along with snail control measures, can keep these diseases at bay, studies have indicated that the unplanned construction of dams and irrigation projects can result in habitat expansion of invasive snail species and lead to disease outbreak. The other important prevention measure is to reduce the nutrient load in waterbodies by keeping polluted water out of our rivers and lakes.

11) You have worked on research projects under grants from the World Bank, UNDP, National Geographic Society, the Indian Government and many more. How has your research helped shape policies relating to species and habitat conservation?

Well, it is difficult to pinpoint how my work has helped shape policies for conservation. As a member of IUCN’s Mollusc Specialist Group, I was involved in assessing the Red List status of freshwater molluscs in India. The listing has helped identify species that need urgent attention. I was part of a UNDP-funded programme for the conservation of Dal Lake in Srinagar. The outcome of the study has resulted in the constitution of a committee to monitor the conservation and sustainable use of Dal Lake and its biodiversity elements.

Some of my species-specific studies are aimed at conserving them at the local and regional level. Overall, my research advocates the conservation of India’s biodiversity hotspots.

At ATREE, we work with communities, forest managers, policy makers and citizens for the long-term sustainability and conservation of nature. Beyond the projects I work on, my association with ATREE—which is known for its multi and inter-disciplinary approach to biodiversity conservation—means that I invariably end up being a part of many initiatives and projects that address a range of issues involving multiple stake-holders.

12) What are your plans specific to your work on molluscs, going forward?

The next few years will be exciting. Together with my colleagues and students, I plan to bring forth a guide on freshwater molluscs and a mobile app to serve researchers as well as citizen scientists. Also, our understanding of the evolution and bio-geography of molluscs will be much better. We plan to describe several new species from Northeast India.

Our programme on India Biodiversity Portal called MISS (Mapping Indian Snails and Slugs) aims to engage citizen scientists to document snails and slugs. Anyone interested can log into www.indiabiodiversity.org and contribute photos to the group ‘MISS’. The data generated through this approach will help understand the distribution patterns of Indian snails and slugs.

13) Can you suggest a few books on snails for those interested?

I would suggest ‘Systematic Revision of Land Snails of the Western Ghats’ (https://li01.tci-thaijo.org/index.php/tnh/article/view/103091). There are no popular guides on the molluscs of the Indian region. To anybody interested in understanding molluscs better, I would recommend the two volumes of ‘Phylogeny and Evolution of the Mollusca’ by Winston Ponder and David R. R. Lindberg. Though this book does not help identify snails, it provides an overview of molluscs from their biology to evolution.