The yokozuna shark is perhaps the largest bony fish living in the deep sea known to mankind.
The “Great King” Dominating the Deep Seas
Japanese scientists have captured rare footage of a large, black-skinned shark, regarded as the largest deep-sea fish ever observed, according to the Japan Agency for Marine-Earth Science and Technology (JAMSTEC).
Scientists estimate this “great king” of the ocean can reach sizes of up to 2.5m.
According to scientists at JAMSTEC, this fish was officially recognized as a new species last January and is a top predator in the deep waters of Suruga Bay. To photograph this particularly large fish, they lured it into a cage located 2 kilometers deep, 400 kilometers off the coast of Suruga Bay.
After successfully luring a few yokozuna sharks into the cage, they observed their behavior and estimated their size. One of the “great kings” was seen driving other fish away from the food to feast on it. Scientists estimated this “great king” of the ocean could reach 2.5m, which is oversized even for its species.
Yoshihiro Fujiwara, a senior researcher in deep-sea biology at JAMSTEC, stated: “The fish we discovered this time is so large that we had to double-check our calculations.” He also mentioned that it is likely there are many other mysterious ocean dwellers living in the deep sea, similar to this shark, that have yet to be discovered.
Image of a yokozuna shark provided by JAMSTEC.
To date, six yokozuna sharks have been captured, but the largest among them is considered “small” compared to the oversized specimen, measuring only 1.4m.
Before this “great king” shark, the largest fish found living in the deep sea was the grenadier, with the largest specimen of this oddly named fish measuring 2.1m.
Fascinating Discovery and a Name of Honor
The discovery of this special fish and its naming is also an interesting story. One sunny winter day, oceanographer Yoshihiro Fujiwara was measuring and observing the usual fat and stout fish when suddenly a commotion erupted on the boat.
The crew of the research vessel had just encountered a large, oddly-shaped fish.
“Oh! We have a handfish!” Upon bringing the specimen onboard, its size astonished the crew, reminding them of a “living fossil” typically found in Africa and Indonesia.
JAMSTEC is studying a specimen via scanning.
However, Fujiwara was somewhat skeptical because the Suruga Bay area is known for its dense population of marine life. Moreover, scientists have extensively studied this region since the 19th century, so he thought someone must have discovered this fish before.
Surprisingly, Fujiwara was mistaken! After researching literature and cross-checking with colleagues worldwide, his team at JAMSTEC discovered that the fish with a mouth full of teeth and a large body with a spear-like head was a completely new species – a biological breakthrough.
After discovering a few more specimens, they decided to preserve them in chemicals or freezers for further research. Using scientific methods, they determined it is a type of shark – a widely distributed fish family across the globe.
The issue is that these fish exhibit extraordinary sizes. While their relatives average around 35cm, this group measures an average of 1.4 meters and weighs 25kg – equivalent to a small child. It is essential to note that such sizes, especially the 2.5m “great king” mentioned above, are incredibly rare in species inhabiting waters deeper than 2,000m.
The tooth-filled mouth is a terrifying weapon of these ocean “warriors”.
Thanks to their size, these fish have been honored with the name “yokozuna” – the highest rank in Japan’s traditional sumo wrestler system. However, size alone does not dictate their “warrior” capabilities. This group of fish has a robust body, strong physique, and a more “ferocious” diet compared to their ordinary relatives that primarily hunt jellyfish and plankton.
The yokozuna shark does not settle for such “common” and weak fare; they hunt other fish and even consume carcasses of marine creatures. Furthermore, they are seasoned “athletes” and can swim great distances, in contrast to their 100-plus relatives in the shark family.
Moreover, their arsenal includes a “forest of spears” with 80-100 sharp teeth, ready to obliterate any foe. With such biological characteristics, the yokozuna shark can be likened to a lion or an orca version of the deep sea.
However, there are still many mysteries surrounding this deep-sea fish that scientists are eager to explore further.
