Scientists have discovered a new species of 'music frog' in Arunachal Pradesh, based on morphological, molecular and acoustic evidence.
The new frog of the genus Nidirana is phenotypically distinct from its congeners by a combination of morphological characters, the scientists claimed in an article published in the November 15 edition of the journal Zootaxa.
The scientists Bitupan Boruah, V Deepak and Abhijit Das, conducted field surveys in Changlang and Lohit districts of the northeastern state between August and September, last year.
Nestled within vegetation in shallow pools of water, the scientists found male frogs with 'robust' bodies calling loudly. Other specimens were heard from nearby marshy areas, the edges of a newly constructed pond and the side of a nearby road, they mentioned in the article.
The scientists said that they have collected five of the Noa-Dihing Music Frogs three males and two females. The species is also known as Nidirana noadihing.
The new species was named after the Noa-Dihing River, which is near where the specimens were discovered and collected.
The frog has a "robust" body, with males measuring between approximately 1.8 inches and 2.3 inches long and females measuring between about 2.4 inches and 2.6 inches long, they said.
The frogs have a 'rounded' snout and 'smooth' skin with bony protrusions on their backs. The amphibians have a 'pale cream' line bordered with dark brown running down the centre of their bodies. Their light brown limbs are adorned with dark stripes.
According to the scientists, the new species confirmed for the first time that the Nidirana genus has been found in India. Nidirana species are known in Japan, Taiwan, China, Vietnam, Laos and Thailand.
The amphibians have 'irregular shaped and sized spots' on their eyelids and they have dark stripes around their moderately large eyes. Their pupils are gold-rimmed. Their irises are dark brown and have a golden spackle.
The frogs' throat, forelimbs, thighs and lower legs are light brown and pinkish, according to the study. Their groin and the outside of their thighs are pale yellow with irregular dark olive patches, and their cream-coloured chest and belly have a golden tinge.
Nidirana are known to inhabit swamps, ponds and paddy fields, and they often construct nests to lay their eggs, the study said.
Noa-Dihing Music Frogs are distinguished from other species by their size, their oval toe tips, the tubercles on their backs and their unique call, researchers said.
The discovery of a new species validates the presence of the genus Nidirana from India and emphasises the importance of exploring specialized habitats such as marshlands, which are often overlooked, the scientists observed.