The longest bony fish in the sea may explain old sea serpent sightings
The giant oarfish is a silver ribbon with a crimson fin running its whole length, and it can reach 7 or 8 metres, perhaps even 11. Its snakelike body and rippling swimming style have made it the leading suspect behind centuries of sea serpent stories.
Regalecus glesne holds the title of the world's longest ray-finned, or bony, fish. Most specimens measure about 3 metres, but the record reaches around 7 to 8 metres, possibly 11, with a top weight of 272 kilograms. Older claims of a 17-metre fish are now judged very likely wrong. The body is flattened side to side and scaleless, silver with blue tones and dark wavy spots, and a red dorsal fin runs from between the eyes to the tail tip. Its small pectoral fins are stubby, while the long pelvic fins are shaped like oars, the probable source of its name.
Peter Ascanius described the species in 1772. The genus name comes from the Latin for royal, and glesne refers to a farm at Glesvær near Bergen in Norway, where the first specimen was found. Another nickname, king of herrings, may come from the crownlike rays on its head and from fishermen's belief that it led herring shoals.
It lives in every ocean outside the polar seas, recorded from 72 degrees north to 52 degrees south, though it is commonest from the tropics to middle latitudes and more widespread in the Atlantic than the Pacific. It follows its food, moving through the sunlit upper ocean into the dim twilight zone; the deepest confirmed sighting, from the Gulf of Mexico, was between 463 and 492 metres down.
Few larvae have ever been found. They already show the adult's crest rays and long pelvic fins, but their skin is almost see-through, dotted with dark pigment, and they have a small four-rayed tail fin that adults lose. One larva caught off the Croatian island of Palagruža measured just over 10 centimetres. In 2016 the television series River Monsters named the oarfish the most likely origin of sea serpent myths, filming its host diving beside two living specimens in the Mediterranean.
Source: Giant oarfish
