Moscow Blue Guppy

The Moscow Blue Guppy is one of the most elegant and highly prized guppy strains in the ornamental fish hobby. Known for its deep metallic blue coloration, this variety belongs to the famous Moscow line of guppies, which are characterized by solid, intense body colors that extend from the head to the tail without patterns or spots. Due to selective breeding, Moscow Blue Guppies display a rich sapphire to royal-blue sheen that appears almost velvety under proper lighting.

Scientific Name: Poecilia reticulata
Common Name: Moscow Blue Guppy
Origin: Selective breeding (derived from wild guppies in South America)
Difficulty Level: Easy to Moderate

Appearance & Coloration

The defining feature of the Moscow Blue Guppy is its uniform blue coloration covering the entire body and fins.

• Color: Deep metallic blue, ranging from navy to electric sapphire depending on lighting and genetics

• Finish: Smooth, glossy, and iridescent with a reflective sheen

• Body Shape: Streamlined and slightly elongated

• Fins:

  • Males usually have large, flowing dorsal and caudal fins

  • Females are bulkier with shorter fins and a duller blue or grayish tone

Size:

• Males: 3.5–4.5 cm (1.5–2 inches)

• Females: 5–6 cm (2–2.5 inches)

Under strong aquarium lighting, Moscow Blue Guppies often appear to glow, making them a centerpiece fish in planted aquariums.

Behavior & Temperament

Moscow Blue Guppies are peaceful, social, and highly active fish.

• Non-aggressive and community-friendly

• Enjoy swimming in groups

• Constantly active and curious

• Males may chase females during breeding but without serious harm

They are ideal for calm community tanks and are excellent for beginners who want visually striking fish without aggressive behavior.

Tank Requirements

Tank Size

• Minimum: 10 gallons (40 liters)

• Ideal: 15–20 gallons for a small group

Water Parameters

• Temperature: 22–28°C (72–82°F)

• pH: 6.8–7.8

• Water Hardness: Moderate (8–15 dGH)

• Filtration: Gentle filtration preferred (sponge filters work very well)

Tank Setup

• Live plants such as Java moss, guppy grass, hornwort, and Anubias

• Open swimming space with planted corners

• Dark substrate enhances blue coloration

• Moderate to bright lighting to bring out metallic shine

Regular weekly water changes (20–30%) are essential to maintain color and health.

Diet & Feeding

Moscow Blue Guppies are omnivores and thrive on a varied diet.

Recommended Foods

• High-quality guppy flakes or micro-pellets

• Live or frozen foods:

  • Brine shrimp

  • Daphnia

  • Bloodworms (occasionally)

• Plant-based foods:

  • Spirulina flakes

  • Blanched spinach or zucchini (small amounts)

Feeding Frequency:
2–3 small feedings per day
Avoid overfeeding to prevent bloating and water pollution.

A protein-rich and varied diet greatly enhances their blue coloration.

Tank Mates

Moscow Blue Guppies coexist well with other peaceful fish.

Suitable Tank Mates

• Tetras (neon, ember, cardinal)

• Rasboras

• Corydoras catfish

• Mollies and platies

• Small peaceful shrimp (cherry shrimp)

Avoid

• Aggressive fish (cichlids, tiger barbs)

• Fin-nipping species

• Large predatory fish

Breeding Behavior

Like all guppies, Moscow Blue Guppies are livebearers.

• Gestation period: 25–30 days

• Female gives birth to 20–50 fry per cycle

• Fry are independent at birth

Breeding Tips

• Ideal male-to-female ratio: 1 male : 2–3 females

• Dense plants help protect fry from adults

• Fry food:

  • Crushed flakes

  • Baby brine shrimp

  • Micro-worms

Selective breeding is important to maintain the pure blue Moscow strain, as crossbreeding can dilute the color.

Health & Common Issues

Common Problems

• Ich (white spot disease)

• Fin rot (from poor water quality)

• Stress-related color fading

Prevention

• Stable water parameters

• Regular water changes

• Quarantine new fish

• Avoid overcrowding

Moscow Blue Guppies are generally hardy when kept in clean, stable environments.

Lifespan

Average lifespan: 2–3 years
With excellent care, some individuals may live slightly longer.