From CK Nayak
New Delhi: After discovering several new species of frogs, reptiles and bats, scientists have now found the largest and heaviest subterranean fish in one of the caves in Meghalaya.
There are about 250 species of subterranean fish known on Earth, eking out a living in a world of permanent dark and scant food. They are usually small, generally a few inches long, since there’s usually little food or prey to eat.
Interestingly, like most other troglobites (an animal species or population of a species strictly bound to underground habitats such as caves), the creature is basically blind and eyeless though it apparently has some ability to sense light. But the discovered a cave fish is much bigger — growing to nearly a foot and half in length and weighing about 10 times more than any known species.
Locals have reported occasionally seeing the newfound fish in Chympe cave in Jaintia Hills, where waterfalls cascade into a subterranean pool.
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, says Daniel Harries, a study co-author, and could present scientists with a unique opportunity to understand this evolutionary process.
The finding raises many questions, such as how the fish maintain their body size, what they feed on and how they’ve adapted to live in these caves.
The caves are extremely extensive and deep, many of which haven’t yet been explored, the scientist said.
Harries encountered the fish on an expedition led by Thomas Arbenz, a professional cave explorer, in Meghalaya.
There are many caves in the region due to the abundant karst and limestone, which can be carved by rainwater.
The team had seen a photograph of the fish from a fellow explorer, and suspected it was a new species.
But they still couldn’t believe what they found in a small underground cavity, called the Um Ladaw Cave in East Khasi Hills, over 300 feet below the surface.
The team found dozens and dozens of the large creatures, swimming in a pool.
“I had this little net, the sort that you use to catch tropical fish in your tank, and I was standing, looking down,” Harries says.
Realising he needed another method to catch them, he eventually put biscuits in an underwater bag, a ploy that proved successful.