Breeding Guide for Jikin and Toskin | How to Beautifully Raise Japan's Traditional Goldfish Varieties

Jikin and toskin are traditional Japanese goldfish varieties that the nation takes pride in. Both are prized for their distinctive tail shapes and body coloration, and breeding them requires higher technique and knowledge than keeping common goldfish. This article explains the characteristics and breeding points of these two major traditional varieties. If you'd like to revisit the basics of breed selection, see the goldfish breed comparison guide as well.

History and Characteristics of Jikin

Jikin is a variety that has been kept primarily in Aichi Prefecture and has approximately 200 years of history. Its most distinctive feature is the color pattern called "rokurin" (six-scale). The body is white as a base, and individuals with red coloring in only six places—the mouth (lip rouge), both pectoral fins, both ventral fins, and the tail fin—are considered the finest specimens. This rokurin pattern rarely occurs naturally; it is achieved through "choshoku," an artificial color-removal process. The body shape is slender, similar to wa-kin (common goldfish), and the tail is an open shape called the peacock tail. Jikin are active swimmers and require sufficient swimming space. Maintain water temperature at 20–28°C; they are sensitive to sudden water quality changes, so the trick is to perform frequent small water changes rather than large ones.

History and Characteristics of Toskin

Toskin is a variety that originated in Kochi Prefecture, with a round body type and a reflected tail (hantenbi) as its defining features. The reflected tail is a distinctive shape where the tail fin curves forward, and when viewed from above, it has the beautiful appearance of an opening flower. Toskin is also called the "queen of goldfish," and at competitions, the degree of tail reflection, left-right symmetry, and body balance are judged strictly. Traditional toskin breeding is done in a "marubachi," a shallow ceramic container. Breeding in shallow water and a round container allows the tail reflection to develop beautifully. Water depth should be 15–20 cm; if too deep, the tail tends to droop and reflection becomes weak. The ideal water temperature is around 25°C; above 30°C, the fish are prone to health issues.

Practical Techniques for Round-Bowl Breeding

Round-bowl breeding is a traditional method for developing beautiful tails in toskin and jikin. Round bowls can be plastic tubs or ceramic pots, with standard dimensions of 45–60 cm diameter and 15–25 cm depth. With only 20–30 L of water, water-quality management becomes the biggest challenge. No filter is used; instead, water quality is maintained through daily or every-other-day complete water changes, the traditional method. The water for changing should be drawn the day before to allow chlorine to dissipate and to match the temperature. During summer, place the bowl in a sunny location, and expose the goldfish to direct sunlight in the morning to enhance their color. However, direct sunlight in peak summer can cause water temperature to spike, so use screens or shade cloth to block afternoon sun. In winter, bring the bowl indoors or cover the pot with insulating material to retain warmth.

Fundamentals of Tail Finishing and Color Adjustment

Jikin's choshoku involves removing red pigment from fry using chemicals or by hand to achieve the rokurin pattern. Typically, a potassium permanganate solution is used, with the desired red areas protected while the rest of the body is decolorized. This work is extremely delicate; wrong timing, concentration, or duration can injure the fish, so it is safest to perform it under the guidance of an experienced breeder. Toskin tail finishing is, in itself, the result of round-bowl breeding management. Swimming in still, shallow water naturally causes the tail fin to curve and reflect. Young fish may show weak reflection, but it develops with age, so there is no need to rush. However, genetic quality is most important, and selecting fry from good bloodlines is the first step to achieving a beautiful tail.

Disease Prevention and Daily Care

Jikin and toskin are more delicate than common varieties and tend to be prone to disease. Especially in round-bowl breeding without a filter, water quality deteriorates quickly, raising the risk of white spot disease and tail rot. The basic principle of prevention is daily water changes and careful feeding management. Feed 1–2 times per day, giving only amounts the fish can finish within 5 minutes, and remove any uneaten food immediately. Feeding too much high-protein food can cause digestive problems and flipover disease, so choose easily digestible feed. The rainy season and seasonal transitions are times when disease is especially likely to occur. Performing a preventive salt bath at 0.3–0.5% concentration suppresses the activity of disease-causing bacteria. If you notice anything unusual, early isolation and treatment are the key to recovery.

How to Obtain Traditional Varieties

Jikin and toskin are rarely seen in ordinary pet shops or home centers. The following methods are typical for obtaining them:

• Direct purchase from a breeder: Quality is most stable, and you can receive breeding advice
• Through hobby clubs: Regional goldfish hobby clubs sometimes facilitate transfers among members
• Purchase at competitions: These fish are sometimes sold at competition venues, offering a chance to obtain high-quality individuals
• Online shops: Choose from trustworthy specialty shops or breeders

Prices are higher than common goldfish, and well-conditioned individuals can cost several thousand to tens of thousands of yen. However, considering their unique beauty and historical value, such an investment is well worthwhile. BreederDirect also makes it possible to purchase directly from breeders specializing in traditional varieties. Methods for identifying good individuals are explained in detail in the goldfish buying guide.

Jikin and toskin have limited circulation and are difficult to find in ordinary pet shops. BreederDirect allows you to purchase directly from breeders specializing in traditional varieties, and you can also obtain information about bloodlines and breeding advice. Learn breeding techniques from breeders and experience the profound depth of Japanese goldfish culture.