Guwahati: In a major boost to Northeast India’s biodiversity profile, scientists have discovered six new species of the damselfly genus Calicnemia and one new species of Coeliccia from the region — a landmark finding that reshapes the taxonomy of these delicate forest insects.
The peer-reviewed study, published in Zootaxa, was authored by Dattaprasad Sawant, Shantanu Joshi, Ujwala Pawar, Fahim Khan, Viraj Nawge and Krushnamegh Kunte. The specimens are deposited at the National Centre for Biological Sciences (NCBS), Bengaluru.
The discoveries were made in Arunachal Pradesh and Nagaland — landscapes already known for exceptional ecological richness but still yielding scientific surprises.
The newly described species are Calicnemia ardena, Calicnemia arunachala, Calicnemia flavovittata, Calicnemia mimumkoa, Calicnemia naga, Calicnemia rubromacula and Coeliccia magna.
Calling the paper a milestone in Indian odonatology, lead author Dattaprasad Sawant said, “This is truly a landmark contribution — possibly the first publication in 21st-century Indian odonatology to describe seven new species from a single family in one paper.”
He recalled how the journey began in 2022 when Shantanu Joshi first spotted unusual Calicnemia species in the Siang Valley.
“What began as curiosity soon turned into an extraordinary taxonomic adventure. At first glance, I believed these were species described decades ago. But Shantanu’s keen eye for anatomical differences revealed otherwise — at least two new species right from the start. That was just the beginning,” Sawant said.
“With remarkable collections by Fahim Khan, Ujwala Pawar, Viraj Nawge and Dr K. Kunte, the number of new Calicnemia species eventually rose to six — including a specimen collected from Nagaland back in 2014. But discovery was only half the task. Establishing these species scientifically was the real challenge.”
At the time of the study, 23 species of Calicnemia were known globally, several lacking live photographs. Given Northeast India’s geographical proximity to China — a diversity hub for the genus — the team had to compare each potential new species with previously described taxa.
“After tracking down images and specimens of 20 species, three remained elusive. Even Chinese museums and odonatologists could not provide live photographs. That led to two intense months of illustrating all 23 species to highlight their diagnostic differences. What once felt like a taxonomic nightmare became my strongest taxonomic domain,” Sawant added.
He credited Shantanu Joshi for his sharp field observations and acknowledged Dr K. Kunte’s mentorship in shaping the work into what he described as a benchmark taxonomic study.
With this publication, India now becomes the global hotspot for the genus Calicnemia, hosting 14 species — the highest for any country. Alongside the six Calicnemia, the study also describes Coeliccia magna, now the largest known Indian member of its genus.
Most of the discoveries were made in Upper Siang district of Arunachal Pradesh, while Calicnemia naga was described from Nagaland.
Beyond adding new names to the checklist, the study also makes a significant taxonomic revision. Based on the structure of the male genital ligula — a key identifying feature in damselflies — researchers have proposed a third species group within Calicnemia.
Previously, the genus was divided into two groups. However, two of the newly discovered species, C. ardena and C. rubromacula, possess short, bifurcated genital filaments unlike any known group, prompting the creation of a new “ardena group”.
The study also corrects a long-standing taxonomic confusion. Specimens earlier reported from India as Calicnemia erythromelas were found to be misidentified and are now described as Calicnemia naga. Such corrections are crucial for accurate biodiversity records and conservation planning.
Before this study, 23 species of Calicnemia and 80 species of Coeliccia were known globally. The addition of seven new species from a single region underscores the extraordinary biological richness of Northeast India and its importance as a centre of endemism.
Damselflies are important bioindicators, often reflecting the health of freshwater ecosystems. Discoveries like these highlight the ecological value of Arunachal Pradesh’s forest streams and hill habitats — and the many species that may still await discovery.
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