Kikokuryu traditionally are metallic Black and White Koi Carp. When a Koi Carp is described as metallic, the easiest way of defining this by looking at the fins which will be opaque (i.e., not transparent).
The skin of a metallic fish may also look reflective under certain light – not to be confused with Gin Rin, which is a sparkle in the scales. Kikokuryu are also always scaleless. Scaleless skin (known as Doitsu) is derived from cross-breeding Koi with similarly scaleless German mirror carp. Kikokuryu were developed by crossing Kumonryu with doitsu platinum Ogon. The resulting fish while described as Black and White, can be closer to Silver and White, though this is likely to change as the fish grows. Given their links to Kumonryu the Black colouration in Kikokuryu can be fairly unstable, linked largely to water parameter factors. The Black colouration in Kikokuryu will often get much darker in winter as the weather cools.
Kikokuryu are also available as several sub-varieties. Examples of these are Beni Kikokuryu (i.e. Red Kikokuryu). This is very much a Kikouryu but with the addition of Red/Beni on the back of the Koi.
A good Kikokuryu should be beautifully metallic with good skin lustre. The White should be pure, similar to the colour of fresh snow. Likewise, the Black should be ink Black. However, as mentioned previously, this can take time to develop. Most importantly the patterning and colouration of a Kikokuryu should be pleasant to look at.
Kikokuryu, much like the beloved Kumonryu are very exciting fish to own as they change and develop over time. As a result, Kikokuryu make a fantastic addition to any Koi pond.