On a sunny winter day in 2016, marine biologist Yoshihiro Fujiwara was anchored off the coast of central Japan, with a chunky palette, when a hubbub suddenly erupted aboard the ship. The crew of the Shonan Maru has just landed a large, strange fish.
“Wow! We got a coelacanth!” they joked when they picked up a monster so large that it evoked the legendary “living fossil” species found only in Africa and Indonesia.
JAMSTEC
Fujiwara, whose specialty is ‘whale trap’ communities – the rich ecosystems that shoot up and feed whale carcasses – were equally excited and skeptical.
“It was exciting,” he told CBS News. “But it’s a very well-studied bay.”
It is indeed. Researchers have been building a taxonomy of monsters from Suruga, Japan’s deepest bay since the 19th century.
The area is also one of the heaviest fish in the world. Fujiwara surely thought that someone had noticed this colossal being before.
Surprisingly, no one had it. Fujiwara and his team from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) cross-referencing books and consulting with colleagues around the world before shutting down the spear-shaped, purple-colored creature from the depths were indeed a satisfying discovery.
That year, three more samples of the sample fish would be hooked, quickly stored in formaldehyde or frozen for later examination in the laboratory.
JAMSTEC
Dissection, CT scans and other analyzes showed the sample in the alepocephalid family, a deep-sea species that is widespread worldwide and is popularly known as ‘slickheads’ for their scale-free heads and gills. But unlike the much smaller family members, which are on average only 14 centimeters long, it was an animal: it was 55 centimeters long and 55 kilograms and had the size and charge of a small child.
Fujiwara and his team decided to name the new species ‘yokozuna slickhead’, after the highest rank in sumo wrestling.
“I could not believe it,” biologist Jan Yde Poulsen, a research fellow at the Australian Museum and an authority on smooth heads, told CBS News from his base in Denmark.
Poulsen, who co-wrote a paper with the JAMSTEC team in January on the yokozuna-smooth head, was also doubtful when he received the first photo of Fujiwara’s team.
“It’s a very grainy photo, almost like when you see a photo of the Loch Ness monster,” he said. “The fact that you find a new species that weighs 25 kilos is just incredible.”
Despite its hostile deep-sea, pitch-black habitat, the smooth head was not only large, it was brown. While devouring other smooth species of plankton and weak swimmers such as jellyfish, DNA testing of the giant fish’s stomach contents showed that he hunted other fish, and perhaps supplemented the diet by baiting.
Unlike the other 100 oddly smooth species known to the world, the yokozuna is a powerful swimmer who can travel long distances, as evidenced by a few seconds of rare video taken with a bait camera at a depth of nearly 8500 feet were captured.
JAMSTEC
The smooth mouth of the smooth head houses several rows of teeth that conjure up an extraterrestrial monster. Fujiwara’s team tried to count the densely packed fangs and their strictly unofficial conclusion: ’80 to 100 ‘teeth in those jaws.
The physical characteristics, in addition to biochemical analysis, also identified the yokozuna smoothhead as a vertebrate predator – the deep-sea version of a lion or orca.
“We have so many dives worldwide,” Fujiwara said. “But it’s rare to see a top predator.”
Fujiwara, a well-equipped marine agency, owns a range of sophisticated submarines and other deep-sea exploration vehicles. “Most top predators are very active, so (they) can easily escape from our submersible pump.”
His team has found that using specially made long lines – long enough to reach the ocean floor, equipped with hundreds of mackerel hooks – is more effective, though time-consuming. It takes up to four hours to harness these ultra long lines, which are left in the water overnight.
While hundreds of new fish species are identified each year, the inaccessible deep-sea still holds many mysteries.
“We have no idea what’s there,” Fujiwara said.