Seiryū Kiryū Medaka – 清流きりゅうメダカ

A flowing contrast of shadow and shine, born from the depths of refined lineage

Physical Characteristics
The Seiryū Kiryū Medaka is a striking ornamental medaka variety developed from the Miyuki Transparent Scale line. It is renowned for its exceptional contrast—deep internal black pigmentation balanced by silver-blue external iridescence, offering a dual-layered visual experience.

• Internal Pigmentation: Dense black coloration inside the body, especially visible when housed in light-colored containers
• External Iridescence: Sparkling light-blue sheen along the body sides, emerging over generations through careful selection
• Head Appearance: The head remains translucent due to a lack of internal pigmentation, adding soft contrast to the darker body
• Body Type: Standard medaka body with natural swimming posture
• Color Dynamics: Its beauty changes depending on container color and lighting—an intriguing trait appreciated by advanced breeders

Origin and Development

• Lineage: Derived from Miyuki Transparent Scale
• First Recognition: Popularized after breeders noticed the emergence of external shine on top of already present internal melanophore pigmentation
• Evolution: Through successive breeding, external iridescence widened and intensified, giving rise to the refined Seiryū Kiryū line

Breeding Notes

• Fixation & Traits: With each generation, breeders selected for deeper internal black and broader external lamé. Some individuals with the Hikari body type even display full-body iridescence
• Tips for Internal Pigmentation: Use black containers to enhance internal melanophore expression
• Tips for External Shine: External iridescence is more pronounced when housed in green or neutral backgrounds—avoid pure white or black setups for best balance
• Balance of Traits: This variety excels in top-view and side-view observation due to its dual pigmentation style

Conclusion
The Seiryū Kiryū Medaka is a living work of contrast and refinement. With a black shadow flowing beneath a silver light, it captivates breeders seeking both genetic stability and visual drama. Whether in a planted aquarium or a minimalist bowl, this variety delivers presence, character, and evolution in motion.

Sources / 出典:

• 改良メダカWEB図鑑 – 清流きりゅうメダカ No.0251
• 清流きりゅう紹介 – めだかの館オンラインショップ