What Type of Fish Is an Oarfish?

An oarfish is a rare, deep-sea creature known for its ribbon-like body and incredible length—sometimes stretching over 26 feet.

The Deep Sea’s Living Mystery

Imagine pulling a silvery ribbon from the ocean, only it’s alive—and 20 feet long. That’s what encountering an oarfish feels like. These rare, snake-like giants live in ocean depths most people will never see, yet they’ve inspired myths, legends, and awe for centuries.

Even marine biologists still consider the oarfish a mystery. Despite their enormous size and striking appearance, sightings are rare, and much of their life remains undocumented. So what exactly is this creature—and why does it fascinate so many?

What Exactly Is an Oarfish?

Oarfish belong to the family Regalecidae, a small group of deep-sea fish under the order Lampriformes. Three species are known, but the most famous—Regalecus glesne, also called the giant oarfish—is the longest bony fish on the planet.

Key Facts About Oarfish:

• Length: Up to 8 meters (26 feet)

• Body Shape: Long, ribbon-like

• Color: Silvery with blue-black markings

• Habitat: Deep, temperate to tropical oceans

• Family: Regalecidae

• Order: Lampriformes

• Kingdom: Animalia

Unlike sharks or whales, which have cartilage or mammalian structures, oarfish are entirely made of bone, making their size even more remarkable.

Why Do They Look So Strange?

Oarfish have a flattened, eel-like body that tapers into a tail with no pelvic fins. A bright red, flowing dorsal fin starts at the head and runs the full body length like a spine of flame. The head looks almost alien, with large, round eyes and a small, toothless mouth.

These features help the oarfish survive at ocean depths of around 200 to 1,000 meters, where sunlight barely penetrates. The long body allows for undulating motion, ideal for drifting through calm, deep waters with minimal effort.

Why Are They Called “Oarfish”?

The name likely comes from the long, oar-like shape of their bodies. Another theory is that old legends mistook them for sea serpents rowing through the water—thus, “oarfish.” In Japan, they’re called ryugu no tsukai, or “messenger from the sea god’s palace.”

Historically, their rare appearances near shores were considered bad omens—often linked to earthquakes or tsunamis. While no scientific proof connects oarfish with seismic events, the timing of their surfacing has kept those stories alive.

How Often Are They Seen?

Almost never. Oarfish live far below the surface and rarely travel upward. Most human encounters happen when one washes ashore—either sick, injured, or dead. Divers occasionally catch glimpses, but these are extremely rare.

Notable sightings:

• In 2013, two oarfish washed ashore in Southern California just days apart—both over 15 feet long.

• In 2020, divers off Baja California filmed a living specimen, calmly floating upright.

Do Oarfish Pose Any Danger?

No. They aren’t predators and have no interest in humans. Oarfish feed mostly on plankton, krill, and small crustaceans by filtering water through their gill rakers. Despite their size, they have tiny mouths and no teeth.

They’re completely harmless, shy, and gentle—more ghost than monster.

What Do Oarfish Eat?

• Zooplankton

• Krill

• Small crustaceans

• Jellyfish larvae

Their feeding method is passive, more like a whale than a predator. They swim slowly and filter food drifting in the water.

How Do They Reproduce?

Little is known. Scientists believe oarfish spawn in open water, releasing thousands of buoyant eggs that drift near the surface until they hatch. Larvae remain near the top of the ocean before sinking into deeper waters as they mature.

What Makes Oarfish So Fascinating?

• Rarity: Sightings are rare, often by accident.

• Size: Longest bony fish on record.

• Mythology: Tied to sea serpent legends.

• Mystery: Much of their life remains unknown.

They’re one of those rare creatures that remind people the ocean is still largely unexplored. Every oarfish sighting triggers renewed curiosity, speculation, and awe.

FAQs About Oarfish

What is the lifespan of an oarfish?
Exact lifespan is unknown, but estimates suggest they may live up to 10 years or longer in the wild.

Where can oarfish be found?
They inhabit deep waters of all temperate and tropical oceans, from the Atlantic to the Pacific.

Can oarfish be kept in aquariums?
No. Their size, deep-sea habitat, and delicate physiology make them unsuitable for captivity.

Do oarfish have predators?
Likely predators include large deep-sea sharks and sperm whales, but direct evidence is scarce.

Is the oarfish endangered?
No. They are not listed as endangered, but their population is hard to study due to their elusive nature.

Why do oarfish come to the surface?
Usually due to illness, disorientation, or dying. Surface appearances are almost never natural behavior.