How difficult is it to keep Wazumi Medaka?

Intermediate. This is an intermediate-level species. Some prior experience and knowledge of environmental management are recommended.

What is the ideal temperature for Wazumi Medaka?

The ideal temperature for Wazumi Medaka is 18〜28℃. Avoid sudden temperature changes and maintain a stable environment.

What is the lifespan of Wazumi Medaka?

The average lifespan of Wazumi Medaka is 2-3 years. With proper care and nutrition, they can live a long and healthy life.

How large does Wazumi Medaka get?

Wazumi Medaka typically reaches Up to about 4cm SL as an adult. Size may vary depending on care conditions and individual genetics.

What should I feed Wazumi Medaka?

Wazumi Medaka feeds on: Prepared medaka food, green water. Aim for a balanced diet with appropriate feeding frequency.

What is the typical price for Wazumi Medaka?

The price of Wazumi Medaka varies significantly depending on morph, size, and lineage. Check our market price page for the latest pricing information.

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Wazumi Medaka

Intermediate

Oryzias latipes

An improved medaka patterned in white and black. Its black markings are deep and do not fade, which sets it apart from ordinary mottling, whose colour washes out with the background response. It was created in 2019. The lineage chart places it after the black varieties that do not respond to the background.

Difficulty

Intermediate

Temperature

18〜28℃

Lifespan

2-3 years

Size

Up to about 4cm SL

Diet

Prepared medaka food, green water

About

Wazumi is an improved medaka patterned in white and black, listed among the body-colour developments in the Medaka Web Encyclopedia's Lineage Chart of Improved Medaka Ver.7 with a creation date of 2019. Its defining feature is that the black markings are deep and do not fade. Ordinary mottling on improved medaka washes out through the background response, so the pattern looks faint once the fish is moved to a white container; wazumi's black does not fade, and it is therefore classed separately from similar-looking mottling. The background response is the phenomenon by which a medaka looks darker in a black container and paler in a white one: the difference is hard to see in a black container but obvious in a white one. The same chart lists, among the body-colour developments, pure black, which holds its colour through the small-eye trait, black (2006), the first to hold a black body with normal eyes, and orochi (2016), black down to the eyes, belly and fins, with wazumi following them.

Source: Wikipedia (CC BY-SA 4.0)

Lifespan of the Wazumi Medaka

The Wazumi Medaka lives 2-3 years.

Size of the Wazumi Medaka

The Wazumi Medaka grows to Up to about 4cm SL.

Temperature & humidity for the Wazumi Medaka

The ideal temperature for the Wazumi Medaka is 18〜28℃.

Basic Info

Origin

Japan (created in 2019; listed among the body-colour developments in the Medaka Web Encyclopedia's Lineage Chart Ver.7)

Care Specifications

pH: 7–8
Hardness (GH): 9–19 dGH
Water Temp.: 18–28℃

PeacefulGroupBreeding: Moderate

Sources: Medaka Web Encyclopedia: Complete Medaka Care Guide / FishBase Oryzias latipes / Medaka Web Encyclopedia: Lineage Chart of Improved Medaka Ver.7

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

Non-fading black markingsWhite and black two-tone

Sources: Japan Medaka Association: Variety Classification Manual, 5th ed. (Sep 2025) / Medaka Web Encyclopedia: Medaka Traits / Medaka Web Encyclopedia: Lineage Chart of Improved Medaka Ver.7 / Medaka Web Encyclopedia: Black body colour

A curated selection of notable morphs. Inheritance modes are a breeding-planning guide; actual appearance varies with combos.