One day, King Manu was collecting water from a river when a small fish swam into his vessel. As he tried to throw it back, the small fish begged him to save it from the big fish. The king took pity on the fish had grown big so Manu kept it in a tank.

Day after day, the fish kept growing in size and finally it was so big that it had to be taken to the ocean. As Manu was putting the fish in the ocean, the fish told him, "I am Matsya, the avatar of Vishnu. In a few days, a big flood will submerge the whole earth. You must build a big ship and fill it with good people and animals and plants of all kind."

As the fish had predicted, it rained continuously for seven days and seven nights and all the creatures drowned in the flood except those who were of Manu's ship. Manu created a new kingdom on earth with the creatures who had survived.