What are fortune fish?

"Fortune fish" is not a commonly recognized term in the context of fish or aquariums. It's possible you might be thinking of:

* Goldfish: Often associated with luck and prosperity in many cultures, especially in East Asia. They are popular aquarium pets and are sometimes kept in ponds.

* Koi: A type of carp that are often kept in outdoor ponds and are associated with good luck, prosperity, and longevity. They are known for their vibrant colors and patterns.

* Arowana: These fish, sometimes called "Dragon Fish," are also associated with luck and prosperity in some cultures. They are large, predatory fish often kept in large aquariums.

If you could provide more context or details, I might be able to give you a more specific answer. For example:

* Where did you hear the term "fortune fish?"

* What kind of fish are you looking for?

* Are you looking for a specific cultural association?

Please provide more information so I can help you better!