Kōgyoku Medaka (紅玉メダカ) – A Jewel Among Japanese Rice Fish

The Kōgyoku Medaka (紅玉メダカ) is a breathtaking ornamental medaka strain celebrated for its vibrant tri-color pattern and shimmering dorsal shine. Developed by renowned breeder Manabu Tange (丹下 学) of Medaka no Beans in Ehime Prefecture, Japan, this strain has captivated medaka enthusiasts since its release in September 2018.

🎨 Key Features

• Coloration: Displays a striking blend of white, black, and vibrant orange, with a strong emphasis on the orange hue for a vivid appearance.
• Shine: Prominent external light (体外光, taigaikō) runs across the back, lending a metallic luster that enhances the visual appeal.
• Body Shape: Maintains a standard medaka body form, though a longfin version called "Kōgyoku Evolution" later emerged.

📖 Breeding Background and Development

Breeder: Manabu Tange (丹下 学)

Affiliation: Medaka no Beans (めだかのビーンズ)

Location: Ehime Prefecture, Japan

Release Date: September 2018

Mr. Tange is highly respected within the medaka breeding community for his commitment to creating vivid, high-fixation strains. The Kōgyoku Medaka stands as a testament to his skillful breeding, combining intense coloration with strong genetic stability.

🔄 Related Varieties

• Shukōgyoku (朱紅玉): A variety that further emphasizes the deep red tones.
• Ginrin Kōgyoku (銀鱗紅玉): A cross between Kikugin Kōgyoku (菊銀紅玉) and Sanshoku Emerald Fin (三色エメラルドフィン), released in 2021, featuring sparkling scale expression.
• Kōgyoku Evolution (紅玉エボリューション): A longfin variant of the original Kōgyoku Medaka, also developed by Medaka no Beans.

✨ Conclusion

The Kōgyoku Medaka dazzles with its vivid orange, white, and black coloration paired with a brilliant dorsal sheen. Beyond its immediate beauty, it represents the depth and diversity of selective medaka breeding. Its lineage, including derivatives like Shukōgyoku and Kōgyoku Evolution, continues to inspire breeders and collectors alike, maintaining its status as a crown jewel among Japanese rice fish varieties.

※ This article was based on breeder records and strain development notes from Medaka no Beans (めだかのビーンズ).