Deep in the ocean lives a mysterious creature that has frightened sailors for centuries. The giant oarfish (Regalecus glesne) is the world’s longest bony fish, reaching lengths up to 56 feet (17 meters) and weighing up to 600 pounds (270 kilograms). They are found in all temperate and tropical oceans, but are rarely seen due to mainly living at depths around 3,300 feet (1,000 meters). Although the oarfish looks like it swam right out of a sailor’s worst nightmare, it’s actually harmless to humans and feeds mainly on tiny zooplankton and squid. They don’t even have real teeth, but rather specialized structures called gill rakers to catch tiny organisms. In Japan, oarfish have long figured into folklore as the “Messengers from the Sea God’s Palace” because they are thought to predict earthquakes.
The oarfish is sometimes called the “king of herrings” because of its superficial resemblance to these smaller fish, but is more closely related to other deep-sea fishes like the opahs and ribbonfish. The name comes from its long pectoral fins, which resemble oars. Not a lot is known about the conservation status of giant oarfish because they have rarely been observed alive, however fishermen do occasionally pull them up in nets as unwanted bycatch.