Extraordinary footage of a rarely seen giant deep sea fish has been captured by scientists. Using a remotely operated vehicle, they caught a rare glimpse of the huge oarfish, perhaps the first sighting of the fish in its natural setting. The oarfish, which can reach 17m long, has previously only been seen on a few occasions dying at the sea surface, or dead washed ashore. The scientists also filmed for the first time the behaviour of a manefish. Mark Benfield ...