Purachina (Platinum Ogon)

Purachina is an all-white, metallic koi. It is, in fact, the metallic variant of Shiro Muji (literally translated: solid white). Shiro Muji is an unpopular white wagoi (a non-metallic, scaled fish). They are not specifically bred for this species because it is a rather dull fish that almost no one wants in their pond. Most Shiro Muji are therefore Kohaku that have lost their red color and are thus virtually worthless. Purachina, whose only difference from Shiro Muji is its metallic skin, is, however, very popular. Along with Yamabuki Ogon (a completely yellow, metallic koi), they are perhaps the most popular solid-colored metallic fish.

To arise

Metallic koi (Hikari) originated in the 1920s. Sawata Aoki learned that a Magoi (primeval koi) had been caught in the river, with "gold" stripes in its dorsal fin. He purchased this fish and began breeding it, always keeping the offspring with the most metallic color for further breeding. Through a series of intermediate steps (Kabuto and Kinbo), this led to the first Ogon (a single-colored metallic fish) around the time of World War II. Finally, Aoki Koifarm was founded in the 1970s and remains one of the leading producers of metallic koi to this day. Nowadays, there is a metallic version of virtually every wagoi and doitsu variety on the market. The first true Purachina was bred in 1963 by Todao Yoshioko by crossing a Kigoi (a yellow, non-metallic wagoi) with a Nezu Ogon (a metallic, gray koi). For several decades, the best Purachina have come from the breeder Yamacho Yoryo, better known as Choguro, who has mainly focused on breeding snow-white Purachina.

Fukurin

Hikari is the Japanese term for metallic. In metallic fish, the sheen comes from the skin between the scales. This skin between the scales is called fukurin. Not all koi have fukurin; often, the scales overlap like roof tiles. Therefore, fukurin is a prerequisite for metallic fish. The scales are, as it were, embedded in the skin. Fukurin can also occur in non-metallic fish, where the skin between the scales doesn't have a metallic sheen. Fukurin is different from ginrin. In ginrin, the scales reflect light; in fukurin, it's the skin.

To demand

With solid-colored fish, it's crucial that everything is correct in terms of body structure. After all, there's no pattern that can deduce imperfections. Any deviation is mercilessly punished during judging and often even irritates the owner. For example, the fins must be symmetrical and of the correct size and shape, the scales must be perfectly aligned, and the body must have the correct shape and proportions for an impressive appearance. The whiter and glossier the skin, the better. A Purachina swimming in the sun must be a real eye-sore. The appearance of pristine snow, in other words.

Variants

Of course, there's also a doitsu (low-scaling) variety of Purachina, and one with ginrin. These are not often seen and are considerably less popular than Purachina.

So if we list the all-white koi, we get the following six varieties:
Wagoi, non-metallic: Shiro Muji
Wagoi, metallic: Purachina
Doitsu, not metallic: Doitsu Shiro Muji
Doitsu, metallic: Doitsu Purachina
Wagoi, non-metallic with ginrin: GinRin Shiro Muji
Wagoi, metallic, with ginrin: GinRin Purachina