New ghost-like fish discovered deep in the Marianas Trench

"This is the first time a fish in this family has ever been seen alive," said fishery biologist Dr. Bruce Mundy with the NOAA. "This is really an unusual sighting."

Video of the eel-like fish was captured during an expedition on NOAA Ship Okeanos Explorer to explore the unknown deep waters of the Marianas Trench in the Pacific Ocean. While exploring a ridge feature at about 2,500 meters (8,200 feet) underwater, the fish measured about 10 centimeters (4 inches) long.

The fish appeared to have transparent, gelatinous skin that lacked scales, and its eyes lacked pigment, giving it a ghostly appearance. The NOAA believes the fish is in the same order as cusk eels (Ophidiiformes), but belongs to a distinct family (Aphyonidae) that has never before been seen alive.

The NOAA believes the rare find highlights "how much we still have to learn about our vast, and unexplored, ocean."