The Black Sea Devil, a Rare Deep-Sea Anglerfish, Filmed for the First Time

Fewer than half a dozen anglerfish have ever been recorded swimming in their undersea habitat

The anglerfish: The original approach to deep-sea fishing

On the edge of California's coast, in an underwater canyon deeper than the Grand Canyon, Monterey Bay hides fantastically monstrous creatures. One of those creatures, a rare "black sea devil" anglerfish was just filmed swimming through its undersea habitat. Now, with the video above (via io9), we can gawk at the fish in the light of day.

If the anglerfish’s toothy jaw and dead-eyed stare creep you out, take some comfort in the fact that this female fish is just three and a half inches long.  Its dainty size, plus its preferences for the dark deep-sea, helps explain why sightings are so rare. "This is the first time we've captured this fish on video in its habitat," says senior scientist Bruce Robison of the Monteray Bay Aquarium Research Institute in a statement. "Anglerfish, like this Melanocetus, are among the most rarely seen of all deep-sea fishes."

There are more than 200 species of anglerfish, and while some can grow longer than three feet, most are less than a foot, reports National Geographic. The females of all species, however, carry a fishing-pole-like spine topped with a glowing "lure" made of flesh. This feature earns the fish its name, as it uses th elure to attract prey close enough to be snatched up its toothsome jaw.

Fewer than half a dozen anglerfish have ever been captured on film, says Robinson in the new video. They know this one is a female because she sports that rod and lure. "Males are ill-equipped for feeding and their sole responsibility appears to be to find a female and mate with her as soon as possible," Robinson says.

Ill-equipped might be an understatement. The male anglerfish is typically much smaller than the female. Once he finds his female anglerfish mate, he "bites into her belly and latches on until his body fuses with hers," writes Matt Soniak for Mental Floss. He says:

With his body attached to hers like this, the male doesn't have to trouble himself with things like seeing or swimming or eating like a normal fish. The body parts he doesn’t need anymore—eyes, fins, and some internal organs—atrophy, degenerate and wither away, until he’s little more than a lump of flesh hanging from the female, taking food from her and providing sperm whenever she’s ready to spawn. 

The slow, almost lumbering swim of the black sea devil in the video attests that she is an ambush predator. She was spotted at 1,900 feet below the surface, in the darkness of the Monterey canyon by the research institute’s remotely operated submersible Doc Ricketts. The vehicle’s cameras got close enough to the fish to see the spots on her sides that help her sense fish nearby and her especially snaggletoothed smile — one tooth was broken and dangling from her jaw. 

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