Hidden lives of the Forest: Two new frog species discovered in Arunachal Pradesh

Deep within the dense forests and river valleys of Arunachal Pradesh, scientists have uncovered two new amphibian species, once again drawing attention to the state’s extraordinary and still largely unexplored biodiversity.

The newly identified frogs Leptobrachium somani and Leptobrachium mechuka belong to the Leptobrachium genus, commonly known as slender armed frogs . Their discovery was announced in a research paper published on January 9 in the international scientific journal PeerJ .

Globally, scientists know of 39 species in this genus, but until now, only four had been recorded in India. The addition of two more species from Arunachal Pradesh marks a significant expansion of India’s amphibian records and underlines the ecological richness of the eastern Himalayas.

The discovery was made by a team of Indian and international researchers from the University of Delhi and Harvard University, who studied fresh field collections from Lower Dibang Valley and Shi Yomi districts . Using a combination of DNA analysis, physical traits and behavioural observations , the scientists confirmed that the frogs are genetically distinct and belong to the Leptobrachium bompu species group.

Despite their unusual name, the frogs are non-venomous and harmless to humans . Like most frogs, they do not produce venom or toxic secretions. Medium-sized in build, adults typically measure between 5 and 8 centimetres , with stout bodies, short limbs and a subtle “slender armed” appearance. Their earthy brown colouring allows them to blend seamlessly into forest leaf litter, offering natural camouflage from predators.

These frogs are nocturnal forest dwellers , becoming active at night, particularly near streams and riverbanks . Their presence is a strong indicator of healthy ecosystems, as amphibians are highly sensitive to changes in temperature, water quality and habitat disturbance.

One of the species, Leptobrachium mechuka , is named after the picturesque town of Mechuka in Shi Yomi district. The other, Leptobrachium somani , honours E Somanath , a veteran journalist and former senior special correspondent of Malayala Manorama — a rare tribute linking biodiversity discovery with journalism.

Welcoming the finding, Arunachal Pradesh Deputy Chief Minister Chowna Mein called it a proud moment for the state. In a social media post, he said the discovery highlights Arunachal’s “rich and still unfolding biodiversity” and reinforces the importance of protecting its fragile forest and river ecosystems.

Experts say the find is a reminder that vast parts of Arunachal Pradesh remain scientifically underexplored. At the same time, it raises concerns about conservation, as such species are often vulnerable to deforestation, habitat loss and climate change .

As scientists continue to document life hidden within these remote landscapes, discoveries like these frogs offer both wonder and warning, celebrating nature’s diversity while underscoring the urgent need to preserve it.