A new video, captured in the waters around Portugal’s Azores islands, has astounded deep-sea biologists, who have hardly ever seen anglerfish alive in their natural environment before, Science reports. The new footage shows a fist-size female anglerfish, resplendent with bioluminescent lights and elongated whiskerlike structures projecting outward from her body. And if you look closely, you’ll notice she’s also got a mate: a dwarf-sized male attached to her underside, basically acting as a permanent sperm provider.
“I’ve been studying these [animals] for most of my life and I’ve never seen anything like it,” says Ted Pietsch, a deep-sea fish researcher at the University of Washington in Seattle.
Most of our knowledge about deep-sea anglerfish comes from dead animals pulled up in nets. Although scientists have identified more than 160 anglerfish species so far, only a handful of videos exist—including the first ever footage of an anglerfish we recently reported on. The new video below is also a first as it shows a sexually united pair. “So you can see how rare and important this discovery is,” Pietsch says. “It was really a shocker for me.”
The groundbreaking video was captured at a depth of 800 meters (2,625 ft) by deep-sea explorers Kirsten and Joachim Jakobsen from a submersible.
The light show C. jordani performs in the video is also a stunner. Similarly to other deep-sea anglerfish, the female has a bioluminescent appendage drifting in front of her head to lure prey. But there is something else in the footage that’s never been seen before: the filaments and fin rays also appear to emit light at their tips and at intervals along their length!
Pietsch suspects that this light is also bioluminescent – meaning, it’s produced within the animal itself – yet admitting that it’s hard to tell whether the structures are reflecting light coming from the submersible or are actually glowing.
The tiny male is also an important part of the discovery. Similarly to many other anglerfish species, C. jordani forms a permanent pair bond, meaning they are monogamous. But it’s not all that romantic, after all. Once a male finds a mate, he bites into her, eventually fusing with her tissue and gaining sustenance through her blood stream. Since scientists have seen dead males latched onto dead females before, they knew about this bizarre reproductive strategy but have never seen it in the wild – until now.
Bruce Robison, a deep-sea ecologist at the Monterey Bay Aquarium Research Institute in Moss Landing, California, was astounded by how flexible the male was despite its solid attachment, seemingly moving around with ease in any direction he wished. “There’s no way I would have ever guessed that from a [museum] specimen.”
Anglerfish are an incredibly diverse group, but are hard to study because they live hundreds to thousands of meters below the ocean surface. With recent advances in deep-water exploration technology, however, videos like this one are giving us a better insight on how these mysterious creatures actually live in their deep, dark environment.