Tōtenkō Medaka – 東天光メダカ

A rising sun in your aquarium—where crimson light meets symmetry

Physical Characteristics
The Tōtenkō Medaka is a striking improved medaka variety known for its rich, deep red coloration and elegant Hikari body type. Originally derived from the famous Yōkihi (楊貴妃) line, it stands out with its refined form and luminous, sunrise-like appearance.

Key features include:

• Bright crimson body color, reminiscent of the vivid red of a morning sun
• Hikari (光) body type, characterized by symmetrical dorsal and anal fins, and a diamond-shaped caudal fin
• Top-view brilliance: The guanine layer along the dorsal side reflects light beautifully, giving the fish a glowing back that changes with the viewing angle

Name Origin
The name “Tōtenkō” (東天光) loosely translates to “Eastern Sky Light,” referencing the fish’s reddish glow that evokes the colors of the rising sun.
Originally intended to be called “Tōtenkōu (東天紅),” meaning “Eastern Sky Crimson,” the breeder chose “light (光)” instead of “crimson (紅)” to emphasize the Hikari body type.

Origin and Development

• First Appearance: Around 2004–2005
• Original Breeder: Mr. Yukio Ōba (大場 幸雄)
• Affiliation: Medaka no Yakata
• Breeding Background: During the stabilization of the Yōkihi Medaka, red-colored individuals with Hikari traits emerged. Mr. Ōba selectively bred only the Hikari-bodied offspring to create and stabilize the Tōtenkō strain.

Fixation & Breeding Tips
The Tōtenkō Medaka has a relatively high fixation rate, making it beginner-friendly.
However, because Hikari body types can be prone to spinal curvature or irregular tail fin shapes, breeders are advised to select for both color depth and form integrity when producing future generations.

Conclusion
The Tōtenkō Medaka is a beautiful embodiment of balance—offering both the intense red color associated with traditional Japanese medaka and the symmetry of the Hikari form. Its historical value, ease of breeding, and eye-catching appearance make it an excellent choice for both collectors and hobbyists alike.

Sources / 出典:

• めだかの館ブログ – 東天光とは？
• 改良メダカWEB図鑑 – 東天光メダカ
• メダカログショップ – 東天光
• Photos provided by SNR Korea