How difficult is it to keep Tsubakuro Medaka?

Advanced. This is an advanced-level species. It requires specialized equipment and advanced husbandry skills with precise environmental control.

What is the ideal temperature for Tsubakuro Medaka?

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

What is the lifespan of Tsubakuro Medaka?

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

How large does Tsubakuro Medaka get?

Tsubakuro 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 Tsubakuro Medaka?

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

What is the typical price for Tsubakuro Medaka?

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

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Tsubakuro Medaka

Advanced

Oryzias latipes

A black, hikari-type medaka expressing both the real long fin and swallow traits. It was created in 2023 by Takashi Hakozaki and certified as Japan Medaka Association new variety No.38, with the common note that it does not respond to the background.

Difficulty

Advanced

Temperature

18〜28℃

Lifespan

2-3 years

Size

Up to about 4cm SL

Diet

Prepared medaka food, green water

About

Tsubakuro is the nickname, read tsubakuro, for an improved medaka classified as the black swallow real-long-fin hikari medaka. It was certified as new variety No.38 under the Japan Medaka Association scheme in the 2023 fiscal year. The breeder is Takashi Hakozaki, and the stated grounds for certification are that both the real long fin and the swallow traits are expressed together. Breeding began by crossing a real long fin with an orochi swallow; the F2 generation showed no fish carrying both traits, so swallow was back-crossed, and both traits were confirmed together in the F2B1 generation. Continued line breeding raised the fixation rate for swallow to around 90 per cent, while fish expressing both real long fin and swallow together run at about 50 to 60 per cent. The common note records that it does not respond to the background, so the black does not pale in a white container. Orochi, used in the cross, is the black variety regarded as the darkest of all, black down to the eyes, belly and fins.

Source: Wikipedia (CC BY-SA 4.0)

Lifespan of the Tsubakuro Medaka

The Tsubakuro Medaka lives 2-3 years.

Size of the Tsubakuro Medaka

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

Temperature & humidity for the Tsubakuro Medaka

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

Basic Info

Origin

Japan (a domestic variety created in 2023 by Takashi Hakozaki; Japan Medaka Association certified new variety No.38)

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 / Japan Medaka Association: Certified New Variety No.38, Tsubakuro

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

Black body colour (no background response)Real long finSwallowHikari body type

Sources: Japan Medaka Association: Variety Classification Manual, 5th ed. (Sep 2025) / Medaka Web Encyclopedia: Medaka Traits / Japan Medaka Association: Certified New Variety No.38, Tsubakuro / Medaka Web Encyclopedia: Swallow

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