Medaka

The Medaka is the Japanese name for the Japanese Ricefish (Oryzias latipes), one of the most important model organisms in scientific research. These small, peaceful fish have been kept in Japan for over 1,000 years and are often featured in Japanese art and culture. They are extremely hardy, can survive in outdoor ponds through freezing winters, and are perfect for nano tanks. Medaka are livebearers that carry their eggs attached to their bodies before releasing them. They come in various colors including wild-type, orange, and white variations.

Care Requirements

Tank Setup

Medaka are perfect for small tanks or outdoor water gardens.

Essential Setup:

• 10+ gallons minimum
• Plants essential for spawning
• Gentle filtration
• Outdoor pond possible
• Temperature 64-75°F

Water Quality

• Temperature: 64-75°F (18-24°C)
• pH: 7.0-8.0
• Water Hardness: Soft to moderate (3-15 dGH)
• Ammonia/Nitrite: 0 ppm
• Nitrate: <20 ppm

Feeding

Omnivores with small mouths:

• Micro pellets or crushed flakes
• Frozen cyclops
• Small live foods
• Natural insects in ponds

Historical Significance

• 1,000+ years: Kept in Japan
• Scientific model: Used in research
• Cultural significance: Featured in art
• Space research: Sent to space station

Behavior & Compatibility

Peaceful and adaptable:

• Schooling: Keep 6+
• Peaceful: Perfect nano fish
• Outdoor hardy: Survive freezing
• Active: Swimming at all levels

Good Tank Mates:

• Other small peaceful fish
• Small shrimp
• Chili rasboras

Breeding

Unique egg-carrying:

• Eggs carried: On female’s body
• Dropped later: Eggs released
• Fertilized: While attached to female
• Easy breeding: In well-planted tanks

Color Variations

• Wild-type: Brownish with stripes
• Orange: Bright orange
• White: Pale/white
• Youkihi: Specific Japanese varieties

Tips for Success

• Hardy and adaptable
• Can live in outdoor ponds
• Perfect for nano tanks
• Keep in schools
• Historic and cultural significance
• Scientific importance