Largest Deep Sea Fish Captured in Rare Footage at 6,000-Foot Deep Off the Coast of Japan

Japanese scientists captured the rare footage of what could be the largest deep-sea fish in the world, according to a news release from Marine-Earth Science and Technology (JAMSTEC).

The sea creature called the yokozuna slickhead fish had only been caught six times and was mainly unknown to scientists.

The sighting was reported first on July 1 in a study titled "Detection of the Largest Deep-Sea-Endemic Teleost Fish at Depths of Over 2,000 m Through a Combination of eDNA Metabarcoding and Baited Camera Observations," published in Frontiers in Marine Science.

Incredibly Rare Largest Deep Sea Fish

Oceans are insanely deep and dark and have remained not fully-studied until now. At 656 feet (200 meters), there is little light that photosynthesis is no longer possible. Then at 3,281 feet (1,000 meters), light simply does not exist at all in the aphotic zone. It is completely dark and is home to many bizarre creatures on Earth that have specialized parts to survive a dark world.

One of those sea creatures is the yokozuna slickhead fish which is believed to be the largest deep sea fish on the planet. They were only caught six times at 6,562 feet (2,000 meters), and the biggest one measured about 4.5 feet (1.3 meters) long.

However, the one caught in the video footage of the Suruga Bay in Shizuoka Prefecture, Japan, was even bigger, with an estimated size of 8.2 feet (2.5 meters) long, making it the largest ever found in the deep sea. JAMSTEC said in a press release that the recent expedition proves that they have lured the largest deep-sea fish to the camera using bait.

The Asahi Shimbun reported that the team has been surveying ecosystems in four sea areas, including the protected zone in Suruga Bay under the Nature Conservation Law in 2020. They collected DNA from the water to confirm the presence of the yokozuna slickhead fish and sent three cameras to the 2,091-meter-deep seafloor around 400 kilometers off Suruga Bay.

One of the cameras caught footage of the fish driving away other fish from the food container about 2.5 meters long. Principal researcher Yoshihiro Fujiwara said that the one they captured in the video was so huge that they needed to recalculate its size. He added that there is a possibility that other large unidentified deep-sea fish species might also be living in the waters.

What Makes a Fish Living Thousands of Feet Deep in the Ocean Special?

The recent expedition has let scientists identify the world's largest boney deep sea fish, according to reports. Compared to the anglerfish, which is another deep sea fish with a little lantern that dangles in front of them that they use to lure their prey, the yokozuna slickhead fish is a lot bigger.

Anglerfish only grow up to a little over a foot long, and some only measure 1 to 7 inches. However, yokozuna slickhead fish can grow up to 8.2 feet long, which is simply massive for a fish from the deep sea, where they would require quite a lot of sustenance to live. That could mean they have developed specialized anatomy and behavior for hunting in the dark to survive.

Check out more news and information on Deep-Sea Creatures in Science Times.