Matsya is believe to be the first avatar of Lord Vishnu in the form of a fish. Basically to rescue Manu and earthly existence from a great deluge and one of the first sapient beings to evolve on the Earth. Matsya is a Sanskrit word which means “fish”. The legends associated with Matsya expand, evolve and vary in Hindu texts. These legends have embedded symbolism, where a small fish with Manu’s protection grows to become a big fish, and the fish saves earthly existence. Matsya iconography sometimes is zoomorphic as a giant fish with a horn, or anthropomorphic in the form of a human torso connected to the rear half of a fish.
There is a story about this in Hindu scriptures. The story tells about a demon (an asura). That asura was very wicked. He snatched the Vedas, the holy books of the Hindus, and went deep inside the sea. At this point, Vishnu changed his form. He became a matsya, that is, a fish. He entered the sea and brought back the Vedas. And he gave the Vedas to Manu. The Hindu scriptures furthermore say that Manu was the first man in the world. According to George Williams, there are overall many versions of the Matsya mythology in the Puranas. The names of the characters, the details, the plot and the message diverge in this genre of texts.
The tale of Matsya appears in chapter 12.187 of the Book 3, the Vana Parva, in the epic Mahabharata. The legend begins with Manu performing religious rituals on the banks of the Cherivi River. A little fish called Matsyaka comes to him and asks for his protection, promising to save him from a deluge in the future. The legend moves in the same vein as the Vedic version. Manu places him in the jar. Once it outgrows it, the fish asks to be put into a tank which Manu helps with. Then the fish outgrows the tank, and with Manu’s help reaches the Ganges River, finally to the ocean.
Manu is ask by the fish to build a ship and be in it with Rishis (sages) and all sorts of grains, on the day of the expected deluge. Manu accepts the fish’s advice. The deluge begins, and the fish arrives to Manu’s aid. He ties the ship to the fish, who then steers the ship to the Himalayas, carrying Manu through a turbulent storm. The danger passes. The fish then reveals himself as Lord Vishnu and gives the power of creation to Manu.
There are also very few temples in India dedicate to Matsya. Prominent ones include the Shankhodara temple in Bet Dwarka and Vedanarayana Temple in Nagalapuram. Lastly the Koneswaram Matsyakeswaram temple in Trincomalee is now destroyed. Matsya Narayana Temple, Bangalore also exists.