When I heard you get koi with red eyes, I fancied the idea and imported a few Kigoi's, especially because I heard that they are fast growers, in demand and rare and because of their almost evil looks and they grow quite large.
When I received them, only three out of the six received had red eyes, and I did not fancy them very much as they are actually quite dull looking, being Albino's.
Also called Akame, they are unable to produce black pigments, and therefore you see the blood in their eyes, making the eyes appearing red.
When I read up a bit on the Albino's, I found that you can also get them in white coloured koi (very rare) and very seldom in a Kohaku, in which case it is not a good example of Kohaku due to the lack of pigments All of the varieties I saw with red eyes were part of the Kawarimono group and I have never seen a metallic red eye koi and was under the impression that you do not get them in any Hikarimono (metallic group)
However, when I emptied one of my large dams this weekend where I had a few Yamabuki Ogons, and discovered with surprise (because they are metallic) that two of them have red eyes.
These Ogons were imported from Hirasawa (well known for their very large Ogons), as Jumbo bloodline Yamabuki Ogons and not Kigoi's.
All I can think of is that the breeder introduced Kigoi's into their spawning to introduce the Jumbo bloodlike into their Yamabuki breeding program, and the red eye albino gene came through?
Herewith a few photos, the last photo showing the difference in colour between a Kigoi (bottom) and one of the Yamabuki's (top).
Maybe I should throw this red eye Yamabuki (female) and a real red eye Kigoi of which I still has a male, into the pot and see what comes out?