The oarfish (Regalecidae) is the largest bony fish known to live, growing up to 11m long. It is found in the euphotic and disphotic zones in temperate and tropical oceans all around the world, yet it is rarely ever seen.
The dorsal fin originates from above the eyes and runs the entire length of the fish. Of the approximately 400 dorsal fin rays, the first 10 to 13 are elongated to varying degrees, forming a trailing crest embellished with reddish spots and flaps of skin at the ray tips. The pelvic fins are similarly elongated and adorned, reduced to one to five rays each. The pectoral fins are greatly reduced and situated low on the body. The oarfish has no anal fin and the caudal fin may be absent as well, with the body tapering to a fine point. All fins lack true spines.
The common name oarfish is thought to be in reference either to their highly compressed and elongated bodies or to the now discredited belief that the fish “row” themselves through the water with their pelvic fins.
The family name Regalecidae is derived from the Latin regalis, meaning “royal”. The occasional beachings of oarfish after storms, and their habit of lingering at the surface when sick or dying make oarfish a probable source of many sea serpent tales.
Although the larger species are considered game fish and are fished to a minor extent, oarfish are rarely caught alive. Their flesh is not well regarded for eating due to its gelatinous consistency