Nishikigoi, better known as koi fish, are a well-known variety of the common carp. They are bright red and white and revered for their vibrance and grace. Even other animals, including their predators ...

Once a simple food fish, koi have transformed into living jewels, with some fetching sky-high prices in the global luxury market. Here's how this happened. In the world of high-end pets, few creatures ...