Overview
The Indian Purple Frog (Nasikabatrachus sahyadrensis), also known as the pignose frog, was hailed upon its scientific discovery in 2003 as one of the most remarkable zoological discoveries of the 21st century. An extraordinary ‘living fossil’ whose closest living relatives are the sooglossid frogs of the Seychelles islands—dating back over 120 million years to when the Indian tectonic plate broke away from Gondwana—this peculiar subterranean amphibian spends almost its entire life burrowed up to 12 feet underground in the Western Ghats of India.
Biology and Physical Characteristics
Nasikabatrachus sahyadrensis features a bizarre and unmistakable morphology sculpted by tens of millions of years of fossorial evolution. It possesses a bulbous, dark purple-to-greyish bloated body, disproportionately small and stocky limbs, and a tiny, conical pointed head terminating in a white, sensitive snout resembling a pig’s snout. Its small, beady eyes sit flush against its head, adapted to living in total darkness. Its muscular hind legs bear hard, shovel-like keratinized spade pads on the heels (inner metatarsal tubercles), enabling it to excavate dense tropical soils backwards with incredible power.
Behavior and Ecology
The purple frog lives a secretive, subterranean existence, foraging inside subterranean termite chambers using its specialized fluted snout and grooved tongue. It emerges above ground for only a single week each year during the torrential onset of the southwest monsoon in May or June. Responding to the drum of heavy monsoon rains, hundreds of adults emerge simultaneously under the cover of night to congregate along torrential mountain streams. Males produce loud, resonant calls from rock crevices to attract females. After rapid amplexus and laying thousands of eggs in seasonal torrent pools, the adults immediately burrow back deep into the earth for another full year.
Conservation and Human Impact
The IUCN assesses Nasikabatrachus sahyadrensis as Endangered due to its small, highly fragmented distribution in Kerala and Tamil Nadu. Construction of hydroelectric dams, road building that fragments breeding streams, and conversion of moist forest valleys into rubber, tea, and cardamom monoculture plantations have degraded critical subterranean habitats. Furthermore, predatory fish introduced into mountain streams consume purple frog tadpoles, which rely on specialized suctorial mouths to cling to rock surfaces in rapids. Local community conservation programs and tadpole rescue efforts are working to safeguard key stream networks.
Interesting Factoid
The Indian Purple Frog spent millions of years hiding underground and was only discovered by scientists in 2003: it leaves its deep underground burrow for only one single week per year to mate during the monsoon rains!
Last updated: October 2026