How difficult is it to keep Raikou Medaka?

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

What is the ideal temperature for Raikou Medaka?

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

What is the lifespan of Raikou Medaka?

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

How large does Raikou Medaka get?

Raikou 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 Raikou Medaka?

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

What is the typical price for Raikou Medaka?

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

AI-generated image

Raikou Medaka

Intermediate

Oryzias latipes

An improved medaka combining vermilion body colour with transparent scales and a black rim. Black appears evenly along the edges of the scales, together with the red cheeks and coloured fins that come from the transparent-scale trait. It is one line name created in 2018 by Yoshimasa Fukagawa.

Difficulty

Intermediate

Temperature

18〜28℃

Lifespan

2-3 years

Size

Up to about 4cm SL

Diet

Prepared medaka food, green water

About

Raikou is one nickname for the vermilion transparent-scale black-rim medaka, registered in the Medaka Web Encyclopedia as type No.0220 and variety No.0205 and created in 2018 by Yoshimasa Fukagawa; coloured fins are recorded as its common note. Black rim is the trait in which black appears so as to emphasise the scales, distributed evenly by the melanophores and never breaking up. On the head the black tends to sit along the edges of the scales, while toward the tail it gathers at their centres. Unlike mottling, where black patches appear here and there, black never jumps to separate parts of the body. The trait was originally seen mostly in semi-transparent-scaled lines, but crossing with transparent-scaled fish brought it into those lines too. Transparent scale is the trait in which the gill covers lack iridophores so the red of the blood shows through and the cheeks appear red, and colour in the fins is another of its features. Raikou expresses this combination on a vermilion body; the same transparent-scale black-rim make-up on a white body is hakuhime, created in 2019 by Kazuaki Senoo.

Source: Wikipedia (CC BY-SA 4.0)

Lifespan of the Raikou Medaka

The Raikou Medaka lives 2-3 years.

Size of the Raikou Medaka

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

Temperature & humidity for the Raikou Medaka

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

Basic Info

Origin

Japan (a domestic variety created in 2018 by Yoshimasa Fukagawa)

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 No.0220 (Raikou)

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

Vermilion body colourTransparent scaleBlack rimColoured fins

Sources: Japan Medaka Association: Variety Classification Manual, 5th ed. (Sep 2025) / Medaka Web Encyclopedia: Medaka Traits / Medaka Web Encyclopedia No.0220 (Raikou) / Medaka Web Encyclopedia: Black rim

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