Aocho Medaka
IntermediateOryzias latipes
A blue miyuki-type medaka whose fins all grow large through fin-shine-based long-fin and morpho expression, especially the tail, whose rays lengthen. 'Rêve' is French for dream.
Rêve is the nickname of a blue body-shine fin-line long-fin morpho fusahire medaka with all-round shine; the Kairyo Medaka Web Zukan credits it to Takuya Tanaka, 2022. It came from a line crossing Grand Bleu (scale-shine long-fin x morpho) with the blue type of Black Morpho. Its fins are enlarged not by real long-fin or hire-naga traits but by fin-shine-based long-fin and morpho expression, most strongly in the tail, whose rays also lengthen ('tail long-fin'), sometimes splitting into tassels ('tail fusahire'). It also shows blue colour, body shine and fin lines. Tail extension distinguishes it from other morpho varieties, and it is a parent of Aquamarine.
Source: Wikipedia (CC BY-SA 4.0)
The Reve Medaka grows to About 3-4 cm (wild medaka reach up to 4 cm SL: FishBase).
Origin
Japan (ornamental cultivar)
Lifespan
Few reliable data
Size
About 3-4 cm (wild medaka reach up to 4 cm SL: FishBase)
Temperature
5〜30℃
Omnivore (floating prepared foods, live foods such as daphnia)
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 (Temminck & Schlegel, 1846)
Synonyms: Aplocheilus latipes (Temminck & Schlegel, 1846), Poecilia latipes Temminck & Schlegel, 1846
Authority databases: GBIF · GBIF · 日本メダカ協会 品種分類マニュアル
Nomenclature follows global taxonomic authority databases.
Ornamental medaka are cultivars of Oryzias latipes. Not listed in the CITES Appendices (checked on Species+) and not regulated under Japan's Invasive Alien Species Act. Japan's wild medaka (Oryzias latipes and O. sakaizumii) are listed as Vulnerable on the Ministry of the Environment Red List and differ genetically by region. Releasing ornamental medaka into rivers, ponds or rice paddies causes genetic pollution through hybridisation with wild fish, so never release them.
Sources: Species+ (CITES) / Ministry of the Environment: list of invasive alien species / Wikipedia (Japanese): Medaka – conservation and genetic pollution
Regulations may change. Always verify the latest information with the relevant authorities.
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The large fins look best from the side in a glass tank; avoid sharp décor and strong currents that could damage them.
Fin extension and tasselling vary; choose breeders whose tails are well extended.
Peaceful and fine with other medaka of similar size. To keep the variety's traits, do not let it breed with other varieties in the same container.
Give floating food that is eaten within 3-5 minutes: at least twice a day in summer, once a day in spring and autumn, and little or none outdoors in winter.
Never release ornamental medaka into rivers, ponds or paddies; hybridisation causes genetic pollution of wild medaka.
Intermediate. This is an intermediate-level species. Some prior experience and knowledge of environmental management are recommended.
Reve Medaka typically reaches About 3-4 cm (wild medaka reach up to 4 cm SL: FishBase) as an adult. Size may vary depending on care conditions and individual genetics.
Reve Medaka feeds on: Omnivore (floating prepared foods, live foods such as daphnia). Aim for a balanced diet with appropriate feeding frequency.
The price of Reve Medaka varies significantly depending on morph, size, and lineage. Check our market price page for the latest pricing information.
Last updated: September 23, 2026
