In July 2017, Aravind N.A. and his team from the Ashoka Trust for Research in Ecology and the Environment (ATREE), Bangalore, set out to study the land snails in the Blue Mountain National Park of Mizoram. On their way back, they explored a small waterfall near the National Highway for freshwater snails and luckily stumbled upon a species new to science. Named Pila mizoramensis, it is the sixth member of the Pila genus from India and the second species to inhabit hill streams. Pila is commonly known as Apple Snails.
“It is currently found in only two localities in Mizoram. The ‘type locality’ or the place from where the first individual was collected is already facing threats due to garbage dumping and other human disturbances such as washing of vehicles near the falls,” explains Dr Aravind N.A., corresponding author of the paper recently published in Molluscan Research. He is an Associate Professor at the Suri Sehgal Center for Biodiversity and Conservation, ATREE.
The team carried out morphological, anatomical and phylogenetic studies to describe the species. “We first look at the shell characteristics – whether left or right coiled. Pila mizoramensis was right coiled. DNA studies showed that it was a close relative of the Southeast Asian species, Pila virescens,” adds first author Maiterya Sil, Research Associate with ATREE. The study was done in collaboration with Indian Institute of Science, Bangalore, and Indian Institute of Scientific Education and Research, Thiruvananthapuram.
The snail, given the common name Mizoram Apple Snail, has a shell height and diameter of about 2.5 cm. Its habitat has perennial waterfalls and the snail was found among algae and semi-aquatic plants in the spray or splash zones of the waterfalls. The locality it was found in has a temperature not exceeding 25 degrees Celsius and receives an annual rainfall of over 2500 mm.
There are only two species of Pila from India which are restricted to streams and the other one Pila saxea is found in the northern Western Ghats. Other members of this group are restricted to stagnant water bodies such as paddy fields, ponds, marshes and lakes.
When asked if these snails are edible, Dr. Aravind NA explained that most species in this genus are edible. “But the new snails are extremely small in size and not found in large numbers like those on agricultural fields. It will be a tough job collecting enough to make a meal,” he chuckles.
The team has planned to carry out further studies to understand the extent of this snail’s distribution in the Northeast Indian region, reproductive biology, ecology and response to habitat disturbances.