Ikarashi Koi Farm（Niigata)

A New Yellow Variant Kawarigoi is Born

Expanding the Possibilities of Goshiki: The Yellow Goshiki “Tamausagi” (Part 1)

In recent years, the Niigata Prefectural Inland Water Fisheries Experiment Station has announced the “Yellow Gosanke,” an increasing number of breeders specializing in unique koi varieties have been working on developing yellow-coloured Nishikigoi.

Igarashi Koi Farm in Nagaoka City, Niigata Prefecture, is undeniably at the forefront of this innovation. Toshinobu Ikarashi, who describes his work as a “niche industry” that creates koi no one else does, shared the story behind the birth of the new yellow variant koi, “Tamausagi”.

Konishi-line Karashi × Uedera-line Ginrin Kohaku

While trying to breed parent Goshiki, a new variety was created.

— You have produced many yellow variant koi, such as Yellow Kin Showa and Kouryu. This time, you have created a yellow Goshiki called “Tamausagi.” What is the process behind its development? 

Toshinobu: I operate as a ‘niche industry,’ so I aim to create koi that other breeders don’t have, like koi that don’t grow large in this variety or with unique colours. I am focused on creating something different that others don’t have (laughs).

Recently, the level of Goshiki has dramatically improved, with many Goshiki surpassing the Gosanke and even winning the Kokugyo Award. However, especially Goshiki over 80 cm with good body structure and beautiful appearance are still very rare. Because of that, I’ve always wanted to create koi that will become the parents of such Goshiki.

— Indeed, it’s rare to see a large Goshiki with a well-developed body shape.

Toshinobu: At one point, I acquired a 103 cm female Doitsu Karashi koi from Konishi (Konishi Koi Farm, Hiroshima) through a connection. Usually, when I see koi over 1 meter, I think, ‘It’s big.’ But this Doitsu Karashi koi was so well-built and had such a beautiful shape. It looked incredibly impressive. The scales along the lateral line were so big they could have been the size of a CD (laughs). Doitsu koi usually have a well-built body but often have small heads, but this one had a beautiful face, and its pectoral and caudal fins didn’t look like they were forced to grow big. It really had a natural, well-balanced body structure.

— What did you cross with that Doitsu Karashi koi?

Toshinobu: At first, I crossed a Wagoi Karashi koi with a Doitsu Karashi koi. Later, when I decided to create a koi that could be used for various breeding purposes in the future, I had an old-line Ginnote Kohaku and the Ginrin Kohaku from Uedera (Uedera Nishikigoi, Hiroshima), which we had bred initially. So, I introduced a male Shusui from Maruhiro, crossing each.

— So, through that process, did you end up with the koi that became the foundation of Tamausagi?

Toshinobu: The ones I crossed with regular Kohaku didn’t produce many good ones, but the ones I bred using Ginrin Kohaku tended to have better body shapes.

— When it comes to Uedera’s ginrin, it’s diamond ginrin, right?

Toshinobu: That’s right. The F1 or F2 from the early days, when I created the diamond ginrin and raised them under controlled conditions, were kept. I was given a male Ginrin Kohaku and crossed it with a Kohaku from Murata in Chiba. We only managed to breed one generation, but the male Ginrin Kohaku that resulted from that was crossed with Konishi’s Doitsu Karashi.

— What kind of koi did you get from the initial cross?

Toshinobu: From the initial cross, we got one yellowish Doitsu-style Kohaku, two Ginrin koi that looked like yellow Kohaku, one Aigoromo, and about three with poor quality koromo. 

Whenever you cross Karashi koi with Kohaku, the body tends to Kokomo with a soot-like appearance. However, the base body was a bit firm, not completely white, but with a yellowish tone and beautiful Koromo. So, while looking for a Goshiki to cross with, I came across the Ginrin Goshiki from Hiroi (Hiroi Koi Farm, Ojiya), and I decided to try it.

— Was ginrin type the better one?

Toshinobu: Ginrin type would be more useful in the future, and for growing them bigger, I figured I could cross them with other koi later. The male Ginrin Goshiki wasn’t particularly shiny, but its silver scaling was beautifully arranged. On the other hand, the female was a yellow-patterned koi with Ginrin originating from a Ginrin Kohaku. Since both had ginrin, I thought they would be a good match, so I first crossed them two years ago. The Kuro Goshiki I bred last year are now in their second generation, and the two-year-olds are beginning to develop their patterns.