Nishikigoi or "Koi" is the Japanese term for Carp.
"Carp is just a very common fish that goes back about 2500 years ago. It originates in China. It was a good food source," said Connie Arthur, an aquarist at the Tennessee Aquarium. She explained that 500 years later, they introduced them tot he Japanese who kept them in rice fields.
"In Asian cultures, they are also viewed as symbols of perseverance, strength, and individualism" said Arthur. Koi are now prized possessions. Arthur said people enter their Koi into competitions, similar to dog shows, but for Koi. There are more than 150 varieties with vibrant shades of orange, red, white, blue, and gold metallic.
"A champion can be sold for as much as 250,000 dollars," said Arthur. The more beautiful and unique-looking, the better.
Koi do not have two common body parts: teeth and a stomach. Instead of teeth, they have grinding plates.
"The way the Koi digest their food is through their intestinal track and the track is about two times the length of their body," said Arthur. Koi can only survive in a very specific environment, with a water temperature between 59 and 77 degrees Fahrenheit. This is because they have a lower immune system.