Dictionary of Ichthyology  

koi = ornamental carp (Cyprinus carpio) especially bred over centuries for colour patterns and body form, each variety having a name in Japanese. The Japanese word is nishikigoi and koi simply means carp. Contests for determining the most ornamental individuals ended with the losers being eaten.

Royal Botanical Garden, Hamilton. Photograph by Brian W. Coad.....more

Canadian Museum of Nature