For centuries, the giant oarfish washing ashore as a scaleless silver ribbon up to 26 feet long inspired sea serpent legends and earned the nickname doomsday fish. This episode separates the monster from the marvel, exploring how the longest bony fish alive actually survives in the deep ocean and why its reputation as an earthquake omen does not hold up to science.

We break down the oarfish's unique anatomy, including its lack of a swim bladder, the hyperossified bones that keep its long spine from snapping, and the gelatinous, water-infused flesh adapted to deep-sea pressure. We explore ROV footage revealing its vertical hovering hunting strategy, its surprising diet of zooplankton, and the self-amputation tactic that leaves nearly every large specimen missing its tail.

• Why oarfish only appear at the surface when sick, dying, or ...