It's no apparition—this new species of ghostly white snailfish was photographed swimming at depths of 4.3 miles (7 kilometers) during a recent expedition to the Peru-Chile trench (see map) in the southeastern Pacific Ocean.
The deepest dwelling vertebrates on Earth, snailfish have been discovered in ocean trenches in other parts of the Pacific. The deepest known fish, found at 4.8 miles (7.7 kilometers), are snailfish filmed in the Japan trench in 2008.
"The tantalizing thing is we've got a very clear photo of the species," said Monty Priede, director of Oceanlab at Scotland's University of Aberdeen, which co-sponsored the expedition. "No one has ever seen this before, and it's never been captured before."
Living so far underwater, the newfound, 6-inch-long (15-centimeter-long) snailfish can withstand pressures equal to 1,600 elephants standing on the roof of a Mini Cooper, according to Oceanlab.
"If you saw that fish in the aquarium you wouldn't say, Wow that's weird," Priede said. "But at a molecular level, in the details of its biochemistry, it is highly adapted in order to survive the high pressure."