Guppies vs. Medaka — Which Is Easier to Keep?

Guppies and medaka are the top two choices for aquarium beginners. Both are beautiful and fun to breed, but their care environments and enjoyment styles differ.

Basic Specs

• Guppy: Body length 3–5cm / Lifespan 1–2 years / Tropical fish (heater required)
• Medaka: Body length 3–4cm / Lifespan 2–3 years / Temperate fish (no heater needed)

Equipment

• Guppy: Tank + filter + heater + lighting. Minimum 30cm tank
• Medaka: Tank or outdoor tub/water lily pot. Filter-free outdoor keeping is possible

Medaka is overwhelmingly easier in terms of equipment. Outdoor keeping means zero electricity costs.

Water Temperature

• Guppy: Maintain 22–26°C. Heater required
• Medaka: Can survive from 5–35°C. Adapted to Japan's four seasons

Medaka is resilient in Japan's climate. Guppies require a heater in winter.

Breeding

• Guppy: Livebearing (fry hatch inside the mother). High fry survival rate. Gives birth approximately once per month
• Medaka: Egg-laying. Lays eggs daily, but parents eat eggs, so collection is necessary

For easy breeding, guppies win. For the challenge of variety fixation, medaka is the choice.

Variety Diversity

• Guppy: Tail shapes (delta, ribbon, etc.) × colors = hundreds of varieties
• Medaka: Youkihi, lame, tricolor, long-fin—variety count has exploded in recent years

Medaka variety development has been growing rapidly in recent years. The high-end variety market is also very active.

Running Costs

• Guppy: 500–1,500 yen/month (electricity + food)
• Medaka: 200–500 yen/month (food only for outdoor keeping)

Medaka has the cost advantage.

Outdoor Keeping

• Guppy: Not possible (will die in winter)
• Medaka: Possible. Can be enjoyed as a biotope

For outdoor enjoyment, medaka is the only option.

Who Should Choose Which

Guppy is recommended if you: - Want to enjoy a beautiful planted aquarium indoors - Want easy breeding (fry management is simpler) - Want to admire gorgeous tail fins

Medaka is recommended if you: - Want to enjoy an outdoor biotope - Want to minimize running costs - Want to challenge variety improvement and fixation - Want to keep fish without worrying about electricity costs

Benefits of Buying on Buri-Choku

On Buri-Choku, you can purchase pedigreed individuals from specialist breeders of both guppies and medaka. Advice on variety fixation rates and breeding tips is available directly from breeders, making it great for beginners too.