Oryzias latipes var.
Rare medaka with greenish external light. Unlike the usual silver-white, the green external light creates a unique atmosphere. Rare and popular with collectors.
Ryokukou (Green Light) medaka is a rare improved variety with a distinctive greenish external body light, unlike the usual silver-white of Miyuki-lineage medaka. The green light emanating from the back, as the name suggests, creates an atmosphere found in no other variety. The special direction of iridophore light reflection is thought to produce this green external light. Highly rare and particularly popular among collectors. Dark top-viewing containers best showcase and reveal the green external light. Hardy in 5–30°C, neutral to slightly alkaline water. Selecting individuals with strongly greenish external light maintains the Ryokukou characteristic, though fixation is difficult and requires patient selection work. Easy to breed with spawning mats.
Origin
Japan (selectively bred variety)
Lifespan
1-3 years
Size
3-4cm
Temperature
5〜30℃
Medaka pellets, daphnia
Black top-viewing container shows green external light best
5-30°C (optimal 20-28°C)
Natural light makes green shimmer more vivid
Ryokukou trait has slightly lower inheritance — selection important
Rare variety — may be difficult to obtain
Intermediate. This is an intermediate-level species. Some prior experience and knowledge of environmental management are recommended.
The ideal temperature for Ryokukou Medaka is 5〜30℃. Avoid sudden temperature changes and maintain a stable environment.
The average lifespan of Ryokukou Medaka is 1-3 years. With proper care and nutrition, they can live a long and healthy life.
Ryokukou Medaka typically reaches 3-4cm as an adult. Size may vary depending on care conditions and individual genetics.
Ryokukou Medaka feeds on: Medaka pellets, daphnia. Aim for a balanced diet with appropriate feeding frequency.
The price of Ryokukou Medaka varies significantly depending on morph, size, and lineage. Check our market price page for the latest pricing information.
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