Fish
Giant oarfish
Regalecus glesne
In Japan it is nicknamed the "messenger from the palace of the dragon god", and its appearance near the coast is sometimes seen as an omen of an imminent earthquake — a legend science has never confirmed but which likely explains the origin of many sea-serpent tales.
🗺️ Geographic range
All the world's temperate and tropical seas, in open water offshore.
📊 Population
No global population estimate available; a deep pelagic species rarely observed alive, not evaluated by the IUCN.
Habitat
- Pacific Ocean · High seas / open water · Mesopelagic zone · Permanent
Behaviour
- Diet
- Zooplankton, small crustaceans and occasionally small fish, filtered while swimming vertically.
- Hunting
- Moves in a vertical position, mouth upward, sucking in prey one at a time.
- Reproduction
- Poorly documented, probably spawns in open water.
Physiology
- Anatomy
- A silvery, ribbon-like body that can exceed 8 m, a red dorsal fin running the entire length.
- Adaptations
- Can move by rippling its long dorsal fin while keeping its body still and vertical.
⚡ Its extraordinary abilities
- Can swim in a perfectly vertical, motionless position, rippling only its dorsal fin
- Its rare, spectacular strandings have fuelled the sea-serpent legend for centuries
🏆 Records
The longest known bony fish
Can exceed 8 metres in length, with some unconfirmed reports of over 11 metres.
Source: French National Museum of Natural History
If you cross paths with this animal…
Risk: None, a harmless species rarely encountered alive.
Behaviour: Fragile out of water, rarely survives a stranding.
Advice: Report any stranded individual to local authorities or an aquarium — every sighting remains valuable to science.
💡 Did you know?
- Likely the origin of many historical "sea serpent" tales reported by sailors.
- In Japan, its appearance near the coast is linked in folklore to the announcement of an earthquake, a belief never scientifically confirmed.