Subterranean fish, numbered at about 250 species on the planet, are usually small and only a few inches long. But in one underground chamber of north-eastern India, researchers have discovered a cave fish growing to nearly a foot and half in length and weighing about 10 times more than any known species.
The fish, described recently in the journal Cave and Karst Science, may still be in the process of evolving to be a separate new species and could present scientists with a unique opportunity to understand this evolutionary process.