Washington, April 3  A fish that crawls into crevices rather than swim may be able to see like humans, perhaps representing an entirely unknown family of fishes, according to a new study.
The fish, sighted in Indonesian waters off Ambon Island, has tan- and peach-coloured zebra-striping, and rippling folds of skin that obscure its fins, making it look like a glass sculpture.

But far from being hard and brittle like glass, the bodies of these fist-sized fish are soft and pliable enough to slip and slide into narrow crevices of coral reefs. It's probably part of the reason that they've gone unnoticed till now.

A single specimen had been spotted by Buck and Fitrie Randolph, with dive guide Toby Fadirsyair and photographed on Jan 28 in Ambon harbour.

A second adult has since been spotted and two more - small, and obviously juveniles - were spotted on March 26 off Ambon. One of the adults laid a mass of eggs, just spotted last Tuesday.

Reference books were consulted but nothing similar to the photographed fish was found. International fish experts eventually approached Ted Pietsch of University of Washington.

"As soon as I saw the photo I knew it had to be an anglerfish because of the leg-like pectoral fins on its sides," said Pietsch.

"Only anglerfishes have crooked, leg-like structures that they use to walk or crawl along the seafloor or other surfaces." Pietsch is considered the world's leading authority on the species.

In the past 50 years scientists have described only five new families of fishes and none of them were even remotely related to anglerfishes, Pietsch said.

Anglerfishes - also called by names like frogfishes and toadfishes - are found the world over and typically have lures growing from their foreheads that they wave or cause to wiggle in order to attract prey. Get too close to the lure and you're lunch.

With its unusual flattened face, the fish's eyes appear to be directed forward, something Pietsch says he's never seen in 40 years as an ichthyologist, suggesting a binocular vision like humans.