Deep sea anglerfish look like some kind of tragic holdover from the Precambrian Era, with their large head, dead eyes, fang-like teeth, and glowing "fishing rod" that extends from their dorsal fin. Scientists had never actually seen these creatures mate in the wild, but sadly, that's no longer case. It is with our deepest regrets that we present to you the very first footage of anglerfish boning.
As Katie Langin reports in Science Magazine, this unprecedented footage was captured by wildlife filmmakers Kirsten and Joachim Jakobsen, a wife and husband team who were exploring an area near the Azores on behalf of the Rebikoff-Niggeler Foundation when they came across the sexy scene.
In the video, a female anglerfish can be seen with her bioluminescent filaments and fin rays extended, while a dwarf male can be seen clasped on to her underbelly. The mating pair has fused together in what biologists call sexual parasitism; the male receives protection and precious nutrients from the female's circulatory system, and in return the female has a steady supply of sperm for when she's ready to spawn. It's the circle of life...
The Jakobsens had been investigating a steep deep-sea wall on the south side of São Jorge Island in their Lula1000 submarine when the female anglerfish and her parasitic mate came into view, which they observed at a depth of 792.48m. The human couple followed the fish couple around for a half hour, filming their movements through the submersible's generously sized 1.07m-wide window.
Afterward, they sent the video to Ted Pietsch, a deep-sea fish researcher at the University of Washington in Seattle, who confirmed the identity of the anglerfish and the nature of the scene. "I've been studying these [animals] for most of my life and I've never seen anything like it," he told Science Magazine. Before this, scientists had already known that anglerfish mated in this way, as suggested by recovered specimens of dead females with dead males still attached to them. Which we have to admit is weirdly romantic.
Another fascinating aspect of the video is the female's filaments and fin rays, which extend outwards in a perimeter around the pair. These glowing structures are like a cross between a cat's whiskers and a spider's web; they sense the waters around the anglerfish for predators and prey. When a prospective meal is detected, the female, who is otherwise sedentary, makes a sudden dash in the direction of the target.
As to how a male anglerfish evades destruction when approaching a female is anyone's guess. Must be his good looks.