naturebriefs
8:41in productionCh. 1 · Vanished then found/ 8:41 · ceiling 15 min
Reptiles & amphibians · Evolution

Purple frog

A frog that vanished for 86 years—then reappeared as proof that India and the Seychelles were once joined.

Nasikabatrachus sahyadrensis is a subterranean frog endemic to the Western Ghats of Kerala. It was formally described in 2003 from specimens collected in Idukki district. Its tadpole was first described in 1917. It feeds underground on termites using a specialised buccal groove and tongue. Its tadpoles possess oral suckers for torrential streams, and their abundance increases with water velocity. Phylogenetically, it is closest to Sooglossidae frogs in the Seychelles. Dam construction during monsoon destroys its critical tadpole microhabitat.

Chapters & takeaways5
  1. 0:55
    Vanished then found

    The adult purple frog went unseen for 86 years after its tadpole was first described in 1917.

  2. 2:12
    Underground termite hunter

    It eats termites underground—unlike any other burrowing frog in India.

  3. 3:00
    Torrent-tethered tadpoles

    Its tadpoles need fast water—and more of them survive where flow is strongest.

  4. 3:57
    Gondwana’s ghost lineage

    Its closest living relatives live 2,500 km away—in the Seychelles.

  5. 5:00
    Drowned by development

    Dams built in monsoon erase the very streams its tadpoles require.

Worth your time?

Yes. See the whole thing.

4.5/ 5
What works
  • subterranean termite foraging
  • torrent-adapted tadpole morphology
  • Gondwanan biogeographic signal
What does not
  • survive dam construction during monsoon
  • surface to feed
  • tolerate habitat alteration
See it if
  • field herpetologists
  • evolutionary biologists
  • Western Ghats conservation practitioners
Skip it if
  • casual garden observers
  • lowland birdwatchers
The written brief1 min read

What the species is and where it came from

Nasikabatrachus sahyadrensis is a frog endemic to the Western Ghats of Kerala, formally described in 2003 from specimens collected in Idukki district. Its juvenile form was identified in 1917, but the adult remained unknown until then.

How it works, in terms someone would actually use

It spends most of its life buried in moist soil, surfacing only briefly during monsoon to breed. It uses its elongated snout and specialised buccal groove to suck termites underground. Its tadpoles cling to rocks in fast-flowing streams using oral suckers.

What it gets right

It gets subterranean foraging right: unlike other burrowing frogs, it hunts termites entirely below ground using morphological adaptations no other Indian frog possesses.

What it does not

It does not surface to feed. It does not tolerate habitat alteration. It does not survive dam construction during monsoon, which destroys its tadpole microhabitat.

What it changed

It rewrote amphibian biogeography: phylogenetic analysis links it not to local frogs but to Sooglossidae in the Seychelles—evidence of ancient Gondwanan fragmentation.

Who it is for, and who it is not

It is for field herpetologists, evolutionary biologists, and conservation practitioners working in the Western Ghats. It is not for casual garden observers or lowland birdwatchers.

Is it worth your time

Yes—if you are in the Western Ghats during monsoon and want to witness a frog that feeds, breeds and evolved entirely apart from other frogs on the Indian subcontinent.

Same habitat · Reptiles & amphibians4 of 35
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