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Hishio (Diamond-Tail) Medaka
AdvancedOryzias latipes
An improved medaka with a diamond-shaped tail on a standard or daruma body. A diamond tail normally belongs to the hikari body type, so fish showing it on a standard body are classed as hishio. Even hishio-to-hishio pairings fix poorly.
Difficulty
Advanced
Temperature
18〜28℃
Lifespan
2-3 years
Size
Up to about 4cm SL
Diet
Prepared medaka food, green water
About
Hishio is the trait in which a fish of the standard or daruma body type has a diamond-shaped tail fin. The Medaka Web Encyclopedia groups it with the fin traits, explained in line with the Japan Medaka Association classification manual. A diamond tail is normally a feature of the hikari body type and does not otherwise occur on a standard body, which is why such fish are classed separately as hishio. Even pairings between hishio fish fix poorly. The commonest confusion is with a hikari-type fish that has a small dorsal fin, which can look like a standard body while still carrying hikari characteristics. The encyclopedia gives three points for telling them apart. First, whether there is light on the back: a standard body never transfers iridophores from the belly to the back, so light on the back means a small-dorsal hikari. Second, the gradation of colour from back to belly, which a standard body shows and a hikari body does not. Third, the colour from head to tail: a hikari fish has a darker head and tends to lose colour beyond the pectoral fins.
Source: Wikipedia (CC BY-SA 4.0)
Lifespan of the Hishio (Diamond-Tail) Medaka
The Hishio (Diamond-Tail) Medaka lives 2-3 years.
Size of the Hishio (Diamond-Tail) Medaka
The Hishio (Diamond-Tail) Medaka grows to Up to about 4cm SL.
Temperature & humidity for the Hishio (Diamond-Tail) Medaka
The ideal temperature for the Hishio (Diamond-Tail) Medaka is 18〜28℃.
Basic Info
Origin
Japan (a fin trait defined in the Japan Medaka Association classification manual)
Care Specifications
- pH
- 7–8
- Hardness (GH)
- 9–19 dGH
- Water Temp.
- 18–28℃
PeacefulGroupBreeding: Hard
Sources: Medaka Web Encyclopedia: Complete Medaka Care Guide / FishBase Oryzias latipes / Medaka Web Encyclopedia: Hishio (diamond tail)
Morphs (Varieties)
The Japan Medaka Association's classification manual sorts varieties by traits that can be seen rather than by genotype, and does not set out how individual traits are inherited. Traits the manual explicitly says can be passed on and produced by selective, multi-generation breeding are listed as line-bred; the rest are grouped under Other.
Other
Diamond tail (hishio)Transparent scale with hishioAlbino small-eye with hishio
Sources: Japan Medaka Association: Variety Classification Manual, 5th ed. (Sep 2025) / Medaka Web Encyclopedia: Medaka Traits / Medaka Web Encyclopedia: Hishio (diamond tail) / Japan Medaka Association: Variety Classification Manual
A curated selection of notable morphs. Inheritance modes are a breeding-planning guide; actual appearance varies with combos.
References & Sources
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.
Primary sources
- Wikipedia
- CITES Appendices (species not listed)
- FishBase (IUCN Red List: Least Concern, assessed 2018)
- Medaka Web Encyclopedia: Complete Medaka Care Guide
- Medaka Web Encyclopedia: Hishio (diamond tail)
- Japan Medaka Association: Variety Classification Manual, 5th ed. (Sep 2025)
- Medaka Web Encyclopedia: Medaka Traits
- FishBase
- GBIF
Taxonomy & Authority
Accepted name: Oryzias latipes (Temminck & Schlegel, 1846)
Authority databases: FishBase · GBIF · Medaka Web Encyclopedia: Hishio (diamond tail) · Japan Medaka Association: Variety Classification Manual
Nomenclature follows global taxonomic authority databases.
Regulations & Conservation Status
Not CITES-listedIUCN LC · Least Concern
Sources: CITES Appendices (species not listed) / FishBase (IUCN Red List: Least Concern, assessed 2018)
Regulations may change. Always verify the latest information with the relevant authorities.
Hishio (Diamond-Tail) Medaka Listings
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