Dark Emerald Fin Medaka (ダークエメラルドフィンメダカ)

Physical Characteristics

The Dark Emerald Fin Medaka is a refined and elegant strain that features a warm amber body tone, semi-transparent scales, and a distinctive emerald-green dorsal shine. One of its key visual traits is the “rinko” (燐光) effect — a net-like, iridescent shine along the back that appears especially vibrant under sunlight.

• Body Color: Deep amber with a subtle reddish glow
• Scales: Semi-transparent, enhancing the depth of color
• Dorsal Shine: Prominent emerald-green “rinko” reflection
• Fins: Clear to slightly pigmented, maintaining a clean and balanced look

Breeding and Lineage

The Dark Emerald Fin Medaka originated as a stabilized strain derived from the Emerald Fin line, particularly from amber-colored offspring that emerged during the development of the original Emerald Fin Medaka.

Despite sharing a name, this strain is genetically distinct from the Bronze Medaka (ブロンズメダカ) and was not created through the same breeding lineage.

• Strain Name (品種名): Dark Emerald Fin
• Breeder (作出者): Ayumu Medaka (あゆむメダカ)
• Released: 2022
• Main Trait (特徴): Rinko (net-like dorsal shine)

Care and Maintenance

This strain thrives under standard medaka care conditions. To fully bring out the dorsal shine and color contrast, outdoor rearing in natural sunlight is recommended.

• Lighting: Sunlight or bright LED light enhances the rinko effect
• Tank Color: Best appreciated in dark or black tubs
• Diet: A well-balanced, nutrient-rich diet supports health and coloration
• Water Quality: Clean, stable water conditions are essential for clarity and scale expressio

Conclusion

The Dark Emerald Fin Medaka offers a rich combination of amber tones and emerald highlights, making it a sophisticated choice for medaka collectors. Its distinct genetic identity and shimmering rinko dorsal shine reflect the thoughtful breeding behind this modern and refined variety.

Image and translation courtesy of: https://medakazukan.net/0740_darkemeraldfin/ https://www.medakanoyakata.jp/?pid=185344305