Japanese Koi Fish

Means 'black' in Japanese. Sumi is one of the primary colours and hence most important colours of a Koi. Good sumi is like an ink painted onto the body of the Koi, thick and lustrous. It also needs to be uniform in terms of it's consistency on the body of the Koi - you don't ideally want a Koi with sumi that has colour variations - note that this is not the same thing as sumi that has not yet come through on the body of the Koi. Quite often you will see a light sumi just 'underneath the surface' of a young Koi - this is sumi that will make it's appearance in time.

Sumi is in fact the oldest original colour of Nishikigoi. This is because Koi were developed from black carp originally. It is in fact also the protective colouring of carp - they change their colour to suit their environment and hopefully avoid ending up down the throat of a hungry heron.

Sumi, like all colours on a Koi, are also a direct reflection of the health of the Koi. Good lustrous dark sumi that increases with age is an indication that the Koi is in good health. Sometimes, sumi can overwhelm the pattern of a Koi (in effect ruining the fish - at least for showing potential). This is not an indictment on the Koi keeper, rather a reflection on good Koi keeping combined with a lesser quality bloodline - but it can happen to even the best breeders and the best tategoi from the best bloodlines... Isn't that just what you wanted to know??

Fortunately with experience, a knowledge of the lines and a good eye, you can minimise the chances of this happening. Also buying an older fish gives you far more foresight into how the fish will develop in the future.