Choosing Tosai Koi

Selecting tosai properly is difficult because young koi are not yet fully developed, so predicting their final appearance requires many considerations. Tosai or Koi that are less than 1 year old very easy to change their color. We must be careful in selecting koi at age tosai. One has to observe the skin in the area around the neck and the shoulders of Koi. It is normal not to have Fukurin at this age, but the skin in the area around the neck and shoulders should appear white and shiny. Whiteness of the skin, however, is not the sole factor in determining skin quality.



The head of Koi has no scales and thus, it appears as the shiniest area. Next to the head is the neck area. Here, because the scales are so small, it will appear shiny. It is perfectly normal for the Koi to have a light Beni color during its Tosai period. When Koi is young, Hiban does not have to be very red. It is more important that Beni has the soft elastic quality and good thickness.

One must look for the shininess throughout the entire body. The sheen should appear as if it is painted with varnish. Full width Fukurin will gradually develop in this type of Koi; the scales will be covered with Fukurin as the fish matures. Presence of fully visible shininess in Tosai will ensure the future development of Fukurin.
Be very careful with very bright hard red Beni in young Koi.

Hard Beni tends to develop an intense redness rather quickly. Unfortunately, as the Koi develops its body this type of Beni will disappear. It is almost certain that Hiban with the hard red Beni during the Tosai period, will most likely break down and lose the Beni. It is usually possible to tell the quality of Beni or Benishitsu at an early age.

Be very careful with very bright hard red Beni in young Koi. Hard Beni tends to develop an intense redness rather quickly. Unfortunately, as the Koi develops its body this type of Beni will disappear. It is almost certain that Hiban with the hard red Beni during the Tosai period, will most likely break down and lose the Beni. It is usually possible to tell the quality of Beni or Benishitsu at an early age.

During the early stages, color can be light and Beni can appear blurry. Koi with brighter red color or pinkish red Beni turns to Rosy Red, while the red with a yellowish shade will develop into the type of red with the shades of persimmon or orange.

A best teacher is the time spent observing the high quality Koi. The small young Koi with round belly will not grow well, and must be avoided. In contrast, the young Koi with small stomachs, which are almost concave in their shape, have the potential to become a jumbo Koi.


Source:
http://matsunosuke.com/joomla/index.php?option=com_content&view=article&id=56:tosai&catid=44:appraisal&Itemid=91