There are so many weird things in the ocean that we’ve yet to lay eyes on, but we’re trying our hardest to spot them all. And recently, researchers knocked another one off the list. The little gelatinous jellyfish seen in the video above was spotted in the waters around Kingman Reef and the Palmyra Atoll. The area is part of the Pacific Remote Islands Marine National Monument, of which large areas remain completely unexplored.
According to Dr. Dhugal Lindsay, a midwater expert who helped identify what exactly it was, this jellyfish is a member of the order Narcomedusae, and an undescribed species within the genus Bathykorus. This is only the second time it has been seen. The first time was back in 2015, when researchers on NOAA Ocean Exploration’s ship Okeanos Explorer discovered it.
“Our team was stumped when we encountered this mysterious gelatinous creature while diving on a previously unexplored guyot north-northwest of Kingman Reef,” wrote scientists from the E/V Nautilus. “One of our experts initially guessed it could be a helmet jellyfish (with missing tentacles), but thanks to our expert, global Scientist Ashore network — connected to the ship via telepresence technologies — we have solved the mystery!”
Although not much is known about the mysterious creature, it’s likely that it eats other gelatinous animals, like jellies or sea cucumbers. Its brown color indicates that it’s probably a predator of bioluminescent prey.
Scientists were filming a little over 4,600 feet deep when the jelly swam past. Since light can’t penetrate that far down, many of the animals that call the zone home bioluminesce.
“Unlike its transparent cousins,” wrote IFLScience, “Lindsay believes that this Bathykorus has evolved its brown-red pigmentation to block bioluminescent light from bioluminescent prey from being externally visible from the animal’s stomach, allowing unique protection from potential predators.”
The sighting of the jellyfish is currently posing more questions than answers, but researchers are excited about finding them.
“Up until recently, jellyfish have been thought to be a trophic dead end,” said Lindsay. “Nothing eats jellyfish because they’re mostly water and they sting an animal’s lips when eaten. But this Bathykorus has the brown pigmentation to protect them — to stop the bioluminescence from showing through their stomachs. Something is trying to eat them.”
It’s thought that this Bathykorus might be just one of a whole group of pigmented jellyfish that have yet to be discovered.
“For all we know, Bathykorus might bioluminesce as well. It could be a different wavelength or a different way to bioluminesce that predators just can’t see. Who knows?” Lindsay told IFLScience.
