Harpoon a Fish Aquarium Guide: Keep Your Catch and Grow It into a Sea Monster

In Harpoon a Fish, a fish you reel in doesn't have to stay a one-off catch: it goes into your aquarium and stays with you as a pet. Once it's placed, that pet is something you grow and evolve, with the long-term goal of raising the biggest and rarest sea monster you can.

From harpoon to aquarium

Placing your catch is the final step of the game's own harpoon routine: aim at your target and fire, time your reels to pull the fish in, then put the caught fish in your aquarium as your new pet. Keep in mind the fish only truly becomes yours once it's reeled in — other players can steal a catch before it's secured, so landing the first shot doesn't guarantee the trophy ever reaches your tank.

What a placed fish can do

A fish in your aquarium is raised as your new pet, and it keeps developing from there. The point of keeping it is evolution: the game's stated goal is to evolve your fish and grow the biggest and rarest sea monster you can find. That makes the aquarium the home of your long-term collection rather than a trophy shelf — a catch you place today is something you keep working on, not a one-time prize.

Keep the loop going

Every future catch follows the same path — harpoon it, reel it in, place it, and keep growing what you already have. New sea monsters wait in deeper water, so there's always another candidate worth catching and raising.

For the catching half in detail, see our guide to catching fish; the raising half is covered in our grow fish and fish evolution guides. If you'd like a boost while you raise your monsters, working codes are kept on our codes page.