“Trout
How the humble trout carries the world upon its back
“Before God made the world, there was nothing but swamp to be seen, in which, however, there dwelt a very large trout. This trout was indeed a mighty fish, for his body reached from one end of the swamp to the other. Now, when the Creator produced the Earth, He made this creature to become its foundation. There lies the living trout beneath the world, taking in and sending out the waters of the sea through his mouth. When he sucks the water in, the ebb of the tide takes place, but when he sends it out the tide flows”….
“The trout upon whose back the world is founded is the cause of tidal waves. Every now and again he takes in a vast quantity of water, and then with an extraordinary effort shoots it out of his mouth in one mighty blow of his breath. It is this which makes the tidal waves.
“So, again, when he shakes himself the consequence is an earthquake. When he moves gently the earthquake is small, but when he is angry and moves furiously it is great. As this is such a dangerous fish, the Creator has sent two deities to stand one on either side of him, to keep him quiet. These divine beings always keep one hand each on him, to hold him down and prevent any severe movements. Whether they eat or drink they must each keep one hand upon him without fail; they may never on any account take it off.”
Source: Ainu Legends: Trout
Further readings:
JAPANESE MYTHOLOGY & FOLKLORE 