to sir loywee: your koi

'Kumonryu' is the term applied to a doitsu koi with a 'killer whale' pattern, i.e., a black body with white markings. The term 'kumonryu' translates to 'nine-crested dragon." Kumonryu koi are unique in the sense that their sumi (black color) is unstable, allowing them to change their black-and-white patterns even after they have matured. Cases such as when a totally black kumonryu has transformed into a totally white one have even been reported. As such, they are also described as koi that are 'forever tategoi.' The kumonryu is a relatively new koi variety, acquiring a category of its own in the All Japan show only in 1994.


Appreciation Criteria Color

The black and white colors of a kumonryu must be deep and solid. 'Jet-black' and 'snow-white' are common descriptions of how the black and white colors of a kumonryu must appear, respectively.
Pattern
The kumonryu is a doitsu koi, so it may or may not have mirror scales along its dorsal and lateral lines. If it does, the mirror scales must be continuous and nicely aligned. If it doesn't have mirror scales, then it must have no scales at all.
Because of the non-permanence of the sumi of a kumonryu, its pattern must not be a basis for its purchase. The depth and quality of the sumi and the body conformation of the koi must be given much more importance. Many koi hobbyists have bought kumonryu koi based on the black-and-white patterns they saw at the time of buying, only to be disappointed several weeks later to see their koi transform into a less striking specimen.



Courtesy: http://www.koiandponds.com/kumonryu.htm