Rare Deep-Sea Encounter: Black Seadevil Anglerfish Filmed Alive for Only the Second Time
“I thought it was A.I.,” said fish biologist Kory Evans after witnessing the surreal footage.
On January 26, off the coast of the Canary Islands, researchers made a once-in-a-lifetime discovery: a black seadevil anglerfish (Melanocetus johnsonii) was seen alive and swimming toward the ocean’s surface—a moment never before captured by human eyes. This marks only the second time in history the elusive creature has been filmed in its natural state.
“It was like a dream come true,” recalls David Jara Bogunyà, a marine wildlife photographer working with the NGO Condrik Tenerife. “When I was a child, I had a book filled with illustrations of deep-sea creatures. They looked so strange, so unreal. Seeing one in front of me felt like watching that book come to life.”
For nearly an hour, Jara and his team aboard the research vessel Glaucus swam alongside and photographed the rarely seen anglerfish—an animal that typically dwells at extreme depths between 650 and 6,500 feet, far beyond the reach of sunlight and casual observation.
The Creature from the Abyss
The black seadevil, whose genus name translates aptly as “black sea monster,” lives up to its fearsome reputation with massive jaws, needle-sharp teeth, and a bioluminescent lure dangling from its forehead—used to hypnotize prey in the pitch-black deep sea. Despite its terrifying appearance, the fish only measures about six inches long—roughly the size of a smartphone—and is described by experts as “mostly soft and squishy.”
(See the first footage of a black seadevil filmed alive in 2014.)
As the new video footage spread online, scientists around the world expressed amazement at the rarity of the sighting.
“When I first saw the footage, I honestly didn’t believe it was real,” says Kory Evans, fish biologist at Rice University. “I thought it was generated by artificial intelligence.”
“It’s incredibly rare to see a deep-sea creature like that anywhere near the surface,” adds Bruce Robison, senior scientist at the Monterey Bay Aquarium Research Institute. He would know—Robison filmed the only other living black seadevil ever recorded, using a remotely operated vehicle (ROV) at a depth of 1,900 feet in Monterey Bay in 2014.
Why Did It Rise to the Surface?
The reasons behind the fish’s appearance near the ocean surface remain speculative, but scientists have a few theories.
“The fact that it wasn’t just intact but actually swimming was remarkable,” says Evans. “These creatures are adapted for stillness. They’re ambush predators, usually just hovering quietly in place. Seeing one actively moving was a complete shock.”
One theory suggests the anglerfish may have swallowed prey with a gas-filled swim bladder, which could have caused buoyancy issues, unintentionally pulling the predator upward. Once that upward motion begins, it can become uncontrollable.
Another possibility relates to the volcanic activity common near the Canary Islands. An undersea thermal vent or fissure may have released a column of warm water, carrying the fish upward with it.
Finally, the fish may have been ingested or attacked by a larger predator—such as a pilot whale, sea lion, or even a large jellyfish—and then either spit out or managed to escape near the surface.
A Glimpse into the Deep Sea’s Hidden World
Unfortunately, the black seadevil died shortly after the encounter. But even a brief opportunity to observe it alive offers invaluable insight into a part of the world we barely understand.
“These fish have been known to science for over a century,” says Robison. “But until recently, all we had to study were dead specimens retrieved from deep-sea trawling nets.”
From those specimens, scientists learned that black seadevils use bioluminescent bacteria in a symbiotic relationship to produce their glowing lure. Also, many anglerfish species—though not necessarily this one—engage in a bizarre reproductive strategy: tiny males fuse with much larger females, effectively becoming living sperm donors.
The body of the recently encountered anglerfish was recovered and donated to the Museum of Nature and Archaeology of Tenerife, ensuring that its legacy will contribute to future scientific research and education.
Evans emphasizes that there is still much more to discover.
“We used to think that life got less diverse as it went deeper. But in a recent study I co-authored, we found that anglerfish actually diversified as they moved into the deep sea. That was unexpected.”
The deep ocean is an extreme environment—marked by crushing pressures, freezing temperatures, and scarce food—yet it hosts a remarkable variety of lifeforms.
“The deep sea is the largest living space on Earth, and most of the animal species on this planet live there,” says Robison. “We are the exception, not the rule. And we still know shockingly little about what’s down there.”