Big-Eye Medaka
IntermediateOryzias latipes
Not a single variety name but an eye trait: wine-red eyes. Derived from albino lines, it differs from grape eye (change-colour) in that the eye colour does not shift with viewing angle.
Ruby eye is not a single variety but a name for an eye trait. The Kairyo Medaka Web Zukan's albino page describes ruby eye as having a trace of melanin and dark red eyes that do not change colour with viewing angle, treating it as similar to albino change-colour (also called grape eye), whose eyes shift from red to black. A medaka reference book, however, says wine-red pseudo-albino eyes are called both 'grape eye' and 'ruby eye', so the names overlap between sources. The Web Zukan's example, Ruby-eye Real Long-fin (yellow panda ruby-eye), derives from albinos and is mostly white, with cream fish too; from a distance the eyes look normal, but close up the red is distinctive. Show entries include 'white ruby-eye real long-fin hikari'. Check the full variety name when buying.
Source: Wikipedia (CC BY-SA 4.0)
The Ruby-Eye 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.
Find listings for this species
From afar the eyes look normal, so a glass tank viewed up close from the side suits it.
Derived from albino lines, colours tend to be white or cream; choose breeders with clearly red eyes.
The red eyes are hard to tell from normal eyes at a distance, so check the actual fish up close when buying.
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.
Beginner. This is a beginner-friendly species. No special equipment or experience is required, and it can be kept successfully with basic care setup.
Ruby-Eye 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.
Ruby-Eye Medaka feeds on: Omnivore (floating prepared foods, live foods such as daphnia). Aim for a balanced diet with appropriate feeding frequency.
The price of Ruby-Eye Medaka varies significantly depending on morph, size, and lineage. Check our market price page for the latest pricing information.
Last updated: September 23, 2026
