The most expensive aquarium fish in the world is a platinum Arawana. This rare fish belongs to a person named Aro Dynasty from Singapore. The price of this fish is estimated at over $80,000 dollars. You may ask why this fish is so expensive and rare? Well, it’s because that this fish is a result of a genetic mutation and there are none others like it… just like a rare diamond, it’s expensive because certain people are willing to pay much for it. Who are these people? Museums, fish collectors, and eccentric rich people.