Oarfish

Oarfish are large, greatly elongated, pelagic Lampriform fishes comprising the small family Regalecidae. Found in all temperate to tropical oceans yet rarely seen, the oarfish family contains four species in two genera. One of these, the king of herrings (Regalecus glesne), is the longest bony fish alive, at up to 17 metres (56 ft) in length.
The common name oarfish is presumably in reference to either their highly compressed and elongated bodies, or to the former (but 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 (to a minor extent) fished commercially, oarfish are rarely caught alive; their flesh is not well regarded due to its gelatinous consistency.
Rare encounters with divers and accidental catches have supplied what little is known of oarfish behaviour and ecology. Apparently solitary animals, oarfish may frequent significant depths up to 1,000 metres (3,300 ft). An oarfish measuring 3.3 metres (11 ft 4 in) and 63.5 kg (140 lb) was reported to have been caught on 17 February 2003 by Ms Val Fletcher using a fishing rod baited with squid, at Skinningrove, United Kingdom. Oarfish feed primarily on zooplankton, selectively straining tiny euphausiids, shrimp and other crustaceans from the water. Small fish, jellyfish and squid are also taken. Large open-ocean carnivores are all likely predators of oarfish, and include the Oceanic whitetip shark.