A giant oarfish: the mirrored harbinger of earthquakes | Helen Sullivan

Oarfish swim vertically, moving up and down and side to side like a cursor. It would be easier to believe they do not exist

A giant oarfish, also known as the king of herrings", is an eight-metre long ribbon of silver, tapered at its tail and on its head wearing a permanently stunned face - as though moments ago it was a normal herring and then the world's largest chef slapped it down on a benchtop and rolled over it with a rolling pin.

These are unpredictable fish," research biologist Milton Love told the New York Times 10 years ago. But in Japan, oarfish are considered highly predictable: they predict the future. See an oarfish, the story goes, and an earthquake will follow. In the months before Japan's 2011 earthquake, one of the most powerful ever recorded, 20 oarfish were found on beaches. They're known as messengers from the sea god's palace", or jinja hime, shrine princesses".

The sea god's palace, Ryg-j, has four sides, each of which faces one of the four seasons. The expression on the oarfish's face, with one wide eye on each side, makes sense viewed like this, too - one side is seeing the past and the other the future. Things don't look good: looking east it sees plum and cherry blossoms, looking west it sees a maple tree making fire in the branches".