



A rare "ghost fish" was discovered during a NOAA research mission, the federal agency announced on Friday.

Scientists have been investigating deepwater environments around the Mariana Trench Marine National Monument and the Commonwealth of the Northern Mariana Islands with the NOAA Ship Okeanos Explorer and happened upon this unusual sea creature — described as having "transparent, gelatinous skin" — which had never before been spotted alive.

Bruce Mundy, fishery biologist with the NOAA National Marine Fisheries Service, Pacific Islands Fisheries Science Center, said in a statement that he was stunned by the ethereal fish.

Mundy told weather.com that there were limitations to making any taxonomical classifications with the animal.

"The trick about the videos is that we can't be certain about the species identification from the video alone," Mundy said in a phone interview. "My first reaction was 'what is that?' And then after that, my reaction was 'oh my gosh, this could be this very rare fish.' And my third reaction was 'it is!' Previously, the fish was brought up with nets but it wasn't alive. Many of these animals are pale, at the bottom of the ocean, this could be because of evolution, lack of light, there's no selection in evolution in the development of colors. Also food is very scarce down there, so animals don't put a lot of energy in pigment patterns."

(MORE: NOAA Discovers Bizarre Creatures in the Mariana Trench )

"This is just remarkable, I am sure that this is an Aphyonid and I am sure that this is the first time a fish of this family has ever been seen alive," he added in a press release. "This is really an unusual sighting."

Video of the fish was recorded in a ridge approximately 2,500 meters deep, a little more than a mile and a half down.

Mundy added that this type of fish has been known since the first deep sea expedition in 1870s.

"It's one of the most poorly known fishes," he said, adding that the fish were not known to dwell in the Mariana Trench.

The agency observed that this sighting was just another reason to believe that we still have a lot to "learn about our vast, and unexplored, ocean."

The discovery was part of an ongoing mission to explore previously unknown areas in the depths of the Pacific Ocean around marine national monuments in the vicinity of the Mariana Trench.

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