Medaka, also known as Japanese Rice Fish, are one of the oldest ornamental fish kept in Japan and have become increasingly popular around the world. Their hardy nature, peaceful temperament and incredible range of colours make them an excellent choice for nano aquariums, planted aquascapes and outdoor ponds. Whether you're just starting or building a premium breeding collection, Medaka are both beautiful and rewarding to keep.

Why You'll Love Medaka

• Hardy and easy to care for
• Available in stunning colour varieties and premium bloodlines
• Perfect for nano aquariums and outdoor tubs
• Peaceful community fish with gentle personalities
• Easy to breed in healthy, well-maintained aquariums

Creating the Ideal Home

Tank Size

Medaka can comfortably be kept in aquariums from 20 litres, although larger aquariums provide greater stability and allow for larger schools. They are equally at home in planted aquariums, patio ponds and outdoor breeding tubs.

Temperature

Medaka are highly adaptable and thrive between 18–28°C. Unlike many tropical fish, they tolerate cooler temperatures exceptionally well, making them ideal for unheated aquariums and outdoor ponds in many parts of Australia.

Water Quality

• Ammonia: 0 ppm
• Nitrite: 0 ppm
• Nitrate: ideally below 20 ppm
• pH: 6.8–8.0

While Medaka are forgiving fish, they still thrive best in fully cycled aquariums with clean, stable water and regular maintenance.

Filtration

Gentle filtration is ideal. Sponge filters are popular for breeding aquariums, while outdoor tubs often rely on plants and biological filtration to maintain excellent water quality.

Aquascaping

Medaka appreciate planted aquariums with floating plants, open swimming areas and gentle water movement. Floating plants also provide shade and make excellent spawning sites for egg-laying females.

Feeding

Medaka are omnivores and eagerly accept a wide variety of quality foods.

• Premium micro pellets
• High-quality flakes
• Baby brine shrimp
• Daphnia
• Frozen foods
• Live foods for conditioning and breeding

A varied diet promotes excellent colour, healthy growth and regular spawning.

Suitable Tank Mates

Medaka are peaceful fish and mix well with other small community species that enjoy similar water conditions.

• Celestial Pearl Danios
• Small Rasboras
• Pygmy Corydoras
• Otocinclus
• Hillstream Loaches
• Freshwater Shrimp
• Peaceful Snails

Avoid housing Medaka with aggressive fish or large predatory species that may outcompete or prey upon them.

Popular Medaka Varieties

• Miyuki Medaka
• Youkihi Medaka
• Lame Medaka
• Blue Miyuki Medaka
• Black Medaka
• White Medaka
• Gold Medaka
• Mixed Colour Medaka

Medaka FAQs

What are Medaka?

Medaka, or Japanese Rice Fish (Oryzias latipes), are small freshwater fish native to East Asia. They have been selectively bred in Japan for centuries, producing hundreds of beautiful colour varieties.

Can Medaka live outdoors?

Yes. Medaka are one of the best fish for outdoor ponds and tubs, provided they are protected from predators and extreme weather conditions.

Do Medaka breed easily?

Yes. Healthy adults spawn regularly during the warmer months. Females carry their eggs briefly before depositing them onto fine plants or spawning mops.

Can Medaka live with shrimp?

Yes. Medaka are generally considered shrimp-friendly and usually ignore adult dwarf shrimp. Very small shrimplets may occasionally be eaten, but dense mosses and plants provide excellent protection.

How many Medaka should I keep?

Medaka are social fish and are happiest in groups of at least six. Keeping them in schools encourages natural behaviour and creates a far more attractive display.