There are about 228,000 known species that live in the ocean, and experts estimate there are another 2 million that remain a mystery. Of these water species, there are several rare fish that humans love to find and collect as pricey pets.
Millions of people worldwide keep aquariums, but the United States is the single-largest importer of ornamental fish in the world, filled with enthusiasts clamoring to find and acquire the sea's rarest treasures. Here, we introduce you to the world’s most expensive fish, ranked from least to most expensive.