Arowana is the most expensive aquarium fish in the world because of its close similarity to a dragon. The Arowana, also known by the Chinese as the "golden dragon" or "living dragon", is said to be the most expensive aquarium fish in the world. It is so expensive because of its close similarity to an actual dragon; it has beautiful metallic scales that reflect the colors of the rainbow, and boasts two "whiskers" on its face. It is a significant symbol of prosperity, because the word fish in Chinese translates to "yu", which also means wealth.