Regalecidae

Regalecidae is a family of fishes commonly known as oarfish. They are the sole family within the order Regaleciformes. Oarfish are characterized by their elongated, ribbon-like bodies, which can reach extraordinary lengths, making them among the longest bony fishes alive. The most famous species, the giant oarfish (Regalecus glesne), has been reliably reported to grow up to 11 meters (36 feet) and possibly even longer, although unconfirmed reports suggest even greater sizes.

These fish are pelagic, meaning they inhabit the open ocean, and are typically found in deep waters, from the surface down to at least 1,000 meters (3,300 feet). Their diet consists mainly of small crustaceans, though they are also known to consume small fish and squid. Oarfish possess a distinctive crest of red fins running along their heads, which they are thought to use for detecting prey.

Due to their deep-sea habitat and elusive nature, oarfish are rarely observed by humans. Sightings are often accidental, typically occurring when they are near the surface, sometimes after storms or when they are sick or dying. Their appearance at the surface has historically led to myths and legends, often associating them with sea serpents or omens of disaster.

The family Regalecidae currently includes three recognized genera: Regalecus, Agrostichthys, and Tentor. Their reproduction is poorly understood, but like most fish, they are believed to spawn eggs. Despite their size, oarfish are not considered dangerous to humans. Their delicate, gelatinous bodies and deep-sea environment make them difficult to study, and much about their life cycle and behavior remains a mystery.