Is the Doomsday Fish Actually a Terrible Omen?

OK, we kind of get why you might look at a giant oarfish and think "doomsday." gorosan / Shutterstock

As land-dwelling humans, the ocean can be both fascinating and a little (or a lot) frightening. It's therefore not all that surprising that an appearance of the large, strange-looking oarfish might make people anxious, especially in our social-media addled age.

Here, we'll look at why and how this gentle marine giant got called a "doomsday fish," and hopefully keep the facts and the legend separate.

The Giant Oarfish: An Elusive, Aquatic Oddball

What people have called the "doomsday fish" is actually the giant oarfish, or to be more scientific, Regalecus glesne. These large fish live in the deep sea, specifically the mesopelagic zone, 660 to 3,300 feet (200 to 1,000 meters) beneath the ocean's surface.

Since oarfish live so deep beneath the surface, in a zone where the light from the surface has almost disappeared, they are rarely sighted. When they did make themselves known, their strange appearance — long, shiny, ribbon-shaped bodies with a red, spiny dorsal fin along their backs — people took notice.

Giant oarfish are the longest bony fish in the ocean, but like many aquatic giants, they are mostly harmless. Well, they're harmless unless you happen to be one of the small crustaceans, zooplankton, squid or jellyfish that make up their diet.

Frequent Sightings and Social Media Stardom

Oarfish tend to keep out of the shallower waters where humans and their cell phones are usually found. But over the past several years, there have been some more sightings, and the videos of these encounters have gone viral.

While dead oarfish have washed ashore for years, some recent sightings have documented apparently live oarfish in shallow waters. In almost all cases, these oarfish are dead or dying, as it's a warning sign that they are quite literally out of their depth and in trouble.

When this happens, these fish tend to cause a sensation, and TikToks and Instagram posts will start popping off.

Why Oarfish Called Doomsday Fish?

While the recent social media buzz is a byproduct of contemporary tech like the ubiquitous smartphone, the idea of oarfish being bad news goes back to ancient times: In some cultures, a sighting of an oarfish was believed to be a bad omen, portending all kinds of misfortune, especially natural disasters such as earthquakes.

In Japanese folklore, these denizens of the deep sea are called "ryugu no tsukai," which translates to "messenger from the sea god's palace," which should give you some indication of how serious it was to encounter one [source: phys.org].

While the idea that oarfish possess or have access to higher powers isn't as popular as it once was, there have been some unsettling recent coincidences. In 2010, months after there were several sightings of dead oarfish along the coast of Japan, the 2011 tsunami (which was caused by an undersea earthquake) occurred, leading to the infamous Fukushima nuclear accident.

What Does the Science Say About Doomsday Fish?

Despite the durability of the doomsday fish legend, there's no scientific evidence that giant oarfish are omens of a natural disaster. While some have speculated that there may be a correlation, and that it may be due to some special sensitivity on the part of this species of fish, so far there's no plausible theory of what this might be.

In fact, the the bulletin of the Seismological Society of America actually published a paper on the matter, concluding that there was no significant connection between oarfish appearances and earthquakes.

But folklore and myth, especially concerning the sea, has a way of coming back in with the tide. It might be comforting to know what modern science says, but don't be surprised if there's a doomsday fish movie coming soon to a theater near you.