Medaka Breed Catalog | Features and Selection Guide for Youkihi, Miyu, and Sanshoku

Medaka Breed Catalog | Features and Selection Guide for Youkihi, Miyu, and Sanshoku

Medaka were once commonly perceived as "drab fish living in rivers and rice paddies," but selective breeding in recent years has dramatically transformed their appearance. The brilliant deep scarlet Youkihi, the Miyu with its mystical sheen on its back, the Sanshoku with its one-of-a-kind pattern—the world of ornamental medaka has evolved into a profound hobby field where gem-like beautiful varieties are continually born.

In this article, we provide clear explanations of popular breed characteristics, difficulty levels, and selection tips—organized by body color, body type, and special patterns—to help both beginners starting their first medaka and experienced breeders searching for their next addition.

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Choosing Breeds by Body Color

Youkihi

Youkihi is one of the most popular medaka varieties for ornamental purposes. True to its name, it's characterized by a vibrant body color ranging from deep orange to vermillion red, and despite its classic status, it remains highly sought after even today.

• Difficulty: Low (Suitable for beginners)
• Price Range: Several hundred to several thousand yen (premium-grade individuals may cost more)
• Care Tips: Sunlight is essential for color enhancement. Raising them outdoors in a sunny location will deepen and intensify their body coloration. Using a black container (such as a black trough) makes the orange color pop and dramatically improves their visual appeal. Selecting feed with color-enhancing properties further boosts results.

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Miyu

Miyu's greatest appeal is the pale blue-white luminescence running along its back—a phenomenon known as "external light" or iridophore shine. This glow results from melanin pigment mutations, with grades finely divided based on the extent of the light pattern, such as "Super Light" or "Full Body."

• Difficulty: Moderate