The oarfish, or king of the herrings, Regalecus glesne, is an obvious candidate for sea-serpent sightings.
The rarely seen king of the herrings is the world's longest bony fish and has been documented to 41 feet in length, with reports to 50 feet, and 600 pounds.
One of the alternate names for the oarfish is King of the Herrings. It grows to over 20 feet in length!