A Deep-Sea Fish of Nightmares Strays Into Shallow Waters

Strange things live in the depths of the ocean.

Even the light of the sun cannot penetrate the inky blackness below. The pressure of the water above is crushing. And yet life somehow survives, adapted to that strange world.

Many of the fish there are partly luminescent to attract prey. They are omnivores, making up for the lack of food at those depths by having big mouths, sharp teeth and a desire to eat almost anything.

It’s a world alien to our own, with creatures seldom seen by human eyes.

But now, at least one fearsome fish from the depths has made a surprise appearance a lot closer to the surface, where it was spotted and filmed late last month.

A black seadevil anglerfish was sighted near the surface, about 2,000 meters off the coast of Tenerife in the Canary Islands, which are part of Spain, by scientists with Condrik Tenerife, a group that normally researches sharks.

This fish with “devil” in its name is no friendly guppy or koi. It is black as the depths in which it normally lives. Its teeth look like razors. Its lidless eyes, staring forward, seem to have a remorseless cruelty. Its mouth, perpetually open, frankly looks as if it wants to swallow you and everything you hold dear.

One positive for nervous swimmers planning a trip to the Canary Islands: The fish is only about six inches long. It also has a less scary alternative name: the humpback anglerfish.

And why does this fellow look so unusual? The deep sea is “a very different environment from surface waters,” said Ben Frable, the senior collection manager of marine vertebrates at the Scripps Institution of Oceanography in Southern California. “The organisms that live there are very uniquely adapted, and to us look very different.”

The fish’s ultrablack body is for camouflage in the deep ocean. “A lot of organisms are producing light — they glow kind of like lightning bugs,” Mr. Frable said. “You don’t want to advertise yourself.”

With food scarce, these fish don’t know when they are getting their next meal. “They’re not great swimmers,” Mr. Frable said. “More like a spider in a web: They’re waiting for something to come to them.”

Of the seadevil, he said, “It’s pretty much evolved to be a giant head.”

Condrik Tenerife credited Laia Valor, a marine biologist, with the discovery. It told the Spanish newspaper Marca that its team had observed the fish for several hours, but that the fish, which normally lives roughly 200 to 2,000 meters deep, was already injured and did not survive.

“It was like a dream come true,” David Jara Boguñá, a photographer with the group, told National Geographic. “When I was a kid, I had a book with some deep-sea creatures, and I loved the illustrations. They were crazy to me. The animals didn’t look real.”

Mr. Frable, who was not involved in the discovery, described the find as “not shocking, but certainly uncommon. It’s amazing that they were able to capture it on film.”

Why was it so far above its natural habitat? Was it lost, curious or something more disquieting?

Condrik Tenerife scientists speculated that the fish’s roaming might have resulted from illness, an unusual current or its fleeing a predator.

“A lot of things could be going on,” Mr. Frable said. “The animal could have been in distress, or worked its way into shallow water accidentally, or was being pursued by a predator.” He said that in the video, the fish appeared stressed, sick or injured.

Where the anglerfish normally lives is not very well lit, and it is very likely that in shallower water the fish is virtually blind.

No doubt many will recoil from the frightening fish seen in the video. But Mr. Frable has a plea.

“They live in a very different environment; they’re going to look weird,” he said. “But they are not gruesome or horrific.”

“People don’t see them as valuable to protect, as a panda bear,” he lamented.