For example, there are koi with light blue spots, ones with large red patches on their backs, or all-metallic gold. But the most winning fish often just boil down to these three varieties.

Did you know some species of pet fish can live as long, if not longer, than dogs and cats? Learn how this wonderful species ...

While koi were originally bred for consumption, like all other carp, farmers began breeding the fish species exclusively as pets in the 1800s, thanks to their uniquely stunning appearance.