Check this out...the world's longest bony fish, the stuff that
most likely gave us stories of sea serpents: The Oarfish.

This is a rather small specimen....because

The oarfish can supposedly grow up to 17m in length and are
believed to live in deep waters. The only ones that come up to the
surface are either sick or dying. But appearences of oarfish in
shallow waters have also been linked to plate tectonic movements:
their recent mass appearences have preceded major earthquakes in
Chile and Japan and Haiti.
Few have seen them alive. Its an enigma like the giant
squid...but here's a footage of an oarfish estimated at 15-30 feet
swimming in its natural habitat at about half a kilometre down.
Giant
'Sea Serpent' Caught on Camera
As for
foodies...this fish does not apparently taste good.