AI-generated image
Sapphire Medaka
IntermediateMedaka with sapphire-like blue shimmer. Combination of lame scales and blue body is enchanting. Relatively new variety.
Difficulty
Intermediate
Temperature
5〜30℃（適温20〜28℃）
Lifespan
2-3 years
Size
3-4cm
Diet
Medaka pellets
About
Sapphire medaka is an improved variety combining lame scales with blue-tinted body color, named for the deep blue radiance reminiscent of a sapphire gemstone. Blue-white lame scattered across the body shines deep blue to indigo depending on light angle. Many strains combine Miyuki external body light with lame. Dark containers best highlight both the blue tint and lame sparkle. Hardy in 5–30°C, neutral to slightly alkaline water. Blue-spectrum LED lighting showcases its beauty particularly well. Selecting for strong blue individuals with dense lame maintains and improves quality across generations.
Basic Info
Origin
Japan (selectively bred variety)
Lifespan
2-3 years
Size
3-4cm
Temperature
5〜30℃（適温20〜28℃）
Diet
Medaka pellets
Care Guide
Container
Black containers highlight blue coloring
Temperature
5-30°C
Lighting
Side lighting shows beauty best
Breeding
Care Specifications
- pH
- 7–8
- Hardness (GH)
- 9–19 dGH
- Water Temp.
- 18–24℃
PeacefulGroupBreeding: Easy
Sources: FishBase: Oryzias latipes / Seriously Fish: Oryzias latipes
Captive Breeding
Egg-laying
- Clutch size
- 8〜48
- Incubation temp.
- 28℃
- Incubation days
- 7〜14 days
- Sexual maturity
- 2 mo
Breeding season: Mid-April to late September (wild, Japan); year-round indoors with >13 h photoperiod and water temperature of 20–28 °C
Breeding notes
Females spawn once each morning, briefly carrying the adhesive egg cluster near the vent (8–48 eggs per female per day). Photoperiods below 13 h/day markedly suppress spawning; water temperatures below approximately 15 °C also inhibit reproduction. Incubation takes roughly 7–14 days depending on water temperature; approximately 7 days near the optimum (~28 °C). Sapphire Medaka is a blue iridescent ornamental colour line of Oryzias latipes; its reproductive biology is identical to the wild type.
Breeding requires planning, proper husbandry, and responsibility. These figures are general guidelines.
Sources: Leaf et al. (2011) Life-History Characteristics of Japanese Medaka Oryzias latipes — Copeia 2011(4):559-565 / Wangsongsak et al. (2013) Effects of Rearing Density, Salt Concentration, and Incubation Temperature on Japanese Medaka Embryo Development — PMC3698680
Morphs (Varieties)
改良メダカは体型×体色×柄×光(体内/体外)×鱗(透明鱗)×ラメ×ヒレ等のトレイト合成。掲載は当該品種を構成する確証トレイトのみで遺伝形式は確証のみ付与(不確実は省略)。遺伝形式は交配の参考。
PolygenicContinuous trait from multiple genes; intensified by selective breeding.
Lame
Other
Blue body
Sources: JMA日本メダカ協会 改良メダカ品種分類マニュアル / 改良メダカWEB図鑑(medakazukan)
A curated selection of notable morphs. Inheritance modes are a breeding-planning guide; actual appearance varies with combos.
References & Sources
Edited & verified by: br-choku editorial team
The taxonomic, regulatory, and husbandry data on this page are compiled and verified against the authoritative primary sources below.
Primary sources
- FishBase: Oryzias latipes
- Seriously Fish: Oryzias latipes
- JMA日本メダカ協会 改良メダカ品種分類マニュアル
- 改良メダカWEB図鑑(medakazukan)
- Leaf et al. (2011) Life-History Characteristics of Japanese Medaka Oryzias latipes — Copeia 2011(4):559-565
- Wangsongsak et al. (2013) Effects of Rearing Density, Salt Concentration, and Incubation Temperature on Japanese Medaka Embryo Development — PMC3698680
- Koger et al. (1999) Variations of light and temperature regimes and resulting effects on reproductive parameters in medaka (Oryzias latipes) — PubMed 10529276
- Saito et al. (2025) Medaka initiate courtship and spawning late at night: Insights from field observations — PMC11819472
Taxonomy & Authority
Accepted name: (Temminck & Schlegel, 1846)
Synonyms: Aplocheilus latipes (Temminck & Schlegel, 1846), Poecilia latipes Temminck & Schlegel, 1846, Oryzias latipes latipes (Temminck & Schlegel, 1846)
Authority databases: FishBase · GBIF · 日本メダカ協会 品種分類マニュアル
Nomenclature follows global taxonomic authority databases.
Sapphire Medaka Listings
Loading latest listingsFind listings for this species
