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Oryzias latipes var.
Characteristic improved medaka with arc-shaped (bow-shaped) external body light on the back. Beautiful arc of light reminiscent of a crescent moon runs along the back. High ornamental value, advanced-level variety.
Tsukiyumi (Crescent Moon Bow) medaka is a distinctive improved variety with arc-shaped external body light on the back resembling a crescent moon bow. While typical Miyuki-lineage medaka have external light running the full length of the dorsal surface, Tsukiyumi's unique arc-shaped light pattern gives it unparalleled individuality. Fixing the arc shape is extremely difficult — individuals with ideal arc-shaped external light appear at very low frequencies. As a result, it is very rare, with high-quality individuals traded at premium prices among collectors. Dark top-viewing containers best reveal the arc-shaped external light. Breeding is possible but producing offspring that maintain the arc shape requires extremely patient selection — a true advanced hobbyist variety.
The Tsukiyumi Medaka lives 2-3 years.
The Tsukiyumi Medaka grows to 3-4cm.
The ideal temperature for the Tsukiyumi Medaka is 20〜28℃.
Hardy in 5–30°C, neutral to slightly alkaline water.
Origin
Japan (selectively bred variety)
Lifespan
2-3 years
Size
3-4cm
Sources: FishBase: Oryzias latipes / Seriously Fish: Oryzias latipes
Selectively bred killifish are trait combinations of body form × body color × pattern × luminescence (internal/external) × scale types (transparent scales) × sparkle × fin morphology and so forth. Published entries include only confirmed traits constituting the given variety, with genetic inheritance patterns provided only for confirmed traits (uncertain cases omitted). Genetic patterns are provided as reference for breeding.
Sources: JMA Japan Medaka Association — Improved Medaka Variety Classification Manual (JA) / Improved Medaka Web Encyclopedia (medakazukan, JA)
A curated selection of notable morphs. Inheritance modes are a breeding-planning guide; actual appearance varies with combos.
Edited & verified by: BreederDirect editorial team
The taxonomic, regulatory, and husbandry data on this page are compiled and verified against the authoritative primary sources below.
Accepted name: Oryzias latipes var. (Temminck & Schlegel, 1846)
Synonyms: Aplocheilus latipes (Temminck & Schlegel, 1846), Poecilia latipes Temminck & Schlegel, 1846, Oryzias latipes latipes (Temminck & Schlegel, 1846)
Authority databases: FishBase · GBIF · Japan Medaka Association — Variety Classification Manual (JA)
Nomenclature follows global taxonomic authority databases.
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Temperature
5〜30℃
Medaka pellets, daphnia
Arc light best visible when viewed from above in black container
Selection of individuals with beautiful arc shape is important
5-30°C (optimal 20-28°C)
Low fixation rate requires careful selective breeding
Highly rare with higher price point
Advanced. This is an advanced-level species. It requires specialized equipment and advanced husbandry skills with precise environmental control.
The ideal temperature for Tsukiyumi Medaka is 20〜28℃. Avoid sudden temperature changes and maintain a stable environment.
The average lifespan of Tsukiyumi Medaka is 2-3 years. With proper care and nutrition, they can live a long and healthy life.
Tsukiyumi Medaka typically reaches 3-4cm as an adult. Size may vary depending on care conditions and individual genetics.
Tsukiyumi Medaka feeds on: Medaka pellets, daphnia. Aim for a balanced diet with appropriate feeding frequency.
The price of Tsukiyumi Medaka varies significantly depending on morph, size, and lineage. Check our market price page for the latest pricing information.
Last updated: August 31, 2026