A STUNNING VIDEO OF PERMANENTLY MATED ANGLERFISHES has been captured by two marine biologists in the Azores, in the Atlantic Ocean off Portugal’s coast.
As deep-sea denizens, anglerfishes are best known for the bioluminescent lures projected from their heads, positioned to attract prey in the dark surrounding waters. With long, sharp teeth, they appear quite fierce, but because of the depths at which they live, much about them is a mystery.
REMARKABLE MATING PROCESS
But they are known for their singular mating process, in which much smaller males bite into the bodies of females and remain affixed, eventually becoming permanently fused to each other. The male receives nourishment from the female’s blood; she receives sperm from him.
Scientists have known this from dead specimens brought to the surface still attached. But it has never been observed in living fishes before.
A HALF-MILE DEEP
Marine biologists Kristen and Joachim Jakobsen captured the scene during a submersible dive at a depth of 800 meters/2,600 feet along a deep-sea wall at São Jorge Island in 2016. The newly released video was published by Science Magazine in its March 23rd online feed, with an article by science writer Katie Langin.
More than 160 species of anglerfishes have been identified. This pair was specified by University of Washington deep sea researcher Ted Pietsch as Caulophryne jordani, more commonly known as the fanfin angler, Ms. Langin notes.
BIOLUMINESCENCE
The whisker-like filaments and fin rays emanating from the female surround them, alert her to any prey that may come in contact with them.
Anglerfishes are known for their bioluminescent lures but this pair also seemed to show light emanating from the filaments – something never been seen before. It’s possibly bioluminescence, Dr. Pietsch is quoted as saying, but it’s hard to tell whether the filaments are actually glowing or just reflecting light from the submersible, Ms. Langin writes.