Nishikigoi (錦鯉) means brocaded carp. The Japanese word combines nishiki, associated with richly patterned brocade, and koi, meaning carp. It describes the ornamental colored carp commonly called koi in English.
Why the Name Refers to Brocade
Brocade is a decorative woven textile. The comparison evokes the colors and patterns of ornamental carp, rather than describing a separate fish species. A white-and-red Kohaku, a three-colored Sanke, and a metallic Ogon can all be described as Nishikigoi.
Why Koi Becomes Goi
In the compound word nishikigoi, the initial sound of koi becomes goi. This is an example of the Japanese sound change called rendaku. The changed spelling does not refer to another kind of carp.
Koi and Nishikigoi in Everyday Use
In English-language pond keeping, koi normally means ornamental colored carp. In Japanese, koi is the broader carp word, while Nishikigoi is the more specific term for ornamental colored carp. Context helps people understand which fish is being discussed; it is unnecessary to assume every conversation using the shorter word will cause confusion.
A Name, Not a Variety
Nishikigoi is an umbrella description. Variety names identify particular combinations of color, pattern, scales, and finish. Doitsu describes reduced scaling, while Ginrin describes sparkling scales; these words can be added to a variety name rather than replacing it.
Use the koi classification directory to put a name to your fish, or read what koi means for the wider language and symbolism discussion. The koi history guide covers the development of ornamental carp.