​

Development and Lineage:

The Midnight Frill Medaka (ミッドナイトフリルメダカ) is an exquisite ornamental fish that combines a deep black body with elegantly extended fins. Developed in 2023 by breeder Seiji Tarumi, this variety showcases a harmonious blend of traits inherited from its parent strains, Emekin and Black Diamond.​

The creation of the Midnight Frill Medaka involved meticulous crossbreeding:​

1. Parent Strains:
   • Emekin (エメキン): Known for its wide and frilled fins, as well as external light (体外光) and surrounding light (一周光) expressions.​
   • Black Diamond (ブラックダイヤ): Recognized for its non-reflective black body and shimmering lamé (iridescent) scales.​
2. Resulting Phenotypes:
   • External Light Type (体外光タイプ): Features a black body with prominent dorsal external light and well-formed wide and frilled fins.​
   • Lamé Type (ラメタイプ): Exhibits a black body adorned with sparkling lamé scales and notable fin extensions.​
   • Jet Black Type (漆黒タイプ): Presents a uniform, deep black coloration without external light or lamé, accompanied by wide fins.​

Key Features:

• Body Coloration: A rich, jet-black hue that remains consistent without fading.​
• Fin Structure: Elongated and wide fins, particularly the caudal and dorsal fins, enhancing its graceful appearance.​
• Phenotypic Variations: Depending on the specific type, individuals may display external light, lamé scales, or a pure black appearance.​

Breeding Insights:

Achieving the combination of a deep black body with pronounced fin extensions has been a challenge in medaka breeding. The Midnight Frill Medaka successfully embodies these traits, marking a significant advancement in the development of black-bodied medaka varieties.​

Care Recommendations:

• Observation Style: To fully appreciate the wide fins and surrounding light expressions, top-view observation is recommended.​
• Container Selection: The choice of container color can influence the visual prominence of the fish’s features:​
  • External Light and Lamé Types: Black containers enhance the shimmering effects.​
  • Jet Black Type: White containers accentuate the deep black coloration.​
• Feeding: Standard medaka feed is suitable; no special dietary requirements are necessary.​
• Water Temperature: Maintaining a temperature between 28–30°C during the growth phase (up to 2–3 months old) can promote optimal fin development.​
• Stocking Density: Providing approximately 2–3 liters of water per fish during the growth phase helps in achieving well-formed fins.​

Conclusion:

The Midnight Frill Medaka stands as a testament to the art of selective breeding, harmoniously blending a deep black body with elegant fin extensions and, depending on the type, shimmering external light or lamé scales. Its unique aesthetic and the dedication involved in its development make it a prized addition to any medaka enthusiast’s collection.

Image and translation courtesy of:  https://www.aqualassic.com/medaka_midnightfrill/ https://medakanoyakata.muragon.com/entry/1473.html