Halfmoon Guppy

The Halfmoon Guppy is widely regarded as one of the most spectacular and artistic guppy varieties ever bred. Named for its breathtaking tail that spreads into a perfect 180-degree half-circle, this guppy is the embodiment of elegance, balance, and selective breeding mastery. When a Halfmoon Guppy swims, it doesn’t just move—it performs.

Scientific Name: Poecilia reticulata
Common Name: Halfmoon Guppy
Category: Fancy Guppy (Tail-type classification)
Difficulty Level: Easy (Care) | Moderate (Breeding quality strains)

Visual Brilliance & Physical Traits

The Iconic Halfmoon Tail

• Tail Spread: True 180° (half-circle shape)

• Edges: Smooth, symmetrical, fan-like

• Tail Size: Large and flowing, often larger than the body

• Movement: Graceful, slow, and dramatic

A true Halfmoon guppy must show full tail extension without folds or gaps, especially under relaxed swimming conditions.

Color Patterns

Halfmoon Guppies are not limited to one color—they are a canvas for endless beauty:

• Solid colors (Red, Blue, White, Black, Yellow)

• Bi-color and tri-color combinations

• Mosaic and leopard patterns

• Metallic and pastel tones

• Moscow-Halfmoon hybrids (premium category)

Lighting enhances their reflective scales, making the tail appear almost painted by light.

Body Shape & Size

• Males: 3.5–4 cm (1.4–1.6 inches)

• Females: 5–6 cm (2–2.5 inches)

• Body: Slim, elegant, well-balanced to support the large tail

Females do not show the Halfmoon tail fully but are essential for breeding quality lines.

Personality & Behavior

Despite their extravagant fins, Halfmoon Guppies are peaceful, curious, and friendly.

• Active swimmers with controlled movements

• Males frequently display tails during courtship

• Non-aggressive and community-safe

• Thrive best in calm environments

Their slow, flowing swim style makes them feel almost meditative to watch.

Ideal Aquarium Setup

Tank Size

• Minimum: 10 gallons (40 liters)

• Recommended: 20 gallons+ for showcasing tail spread

Water Parameters

• Temperature: 24–28°C (75–82°F)

• pH: 7.0–7.8

• Hardness: Moderate (8–15 dGH)

Clean, stable water is crucial—large tails are sensitive to poor conditions.

Tank Design

• Gentle filtration (avoid strong currents)

• Live plants (Java moss, floating plants)

• Open swimming areas

• Dark or neutral substrate

• Moderate to bright lighting

Sharp décor should be avoided to prevent tail damage.

Nutrition & Feeding

Halfmoon Guppies require a balanced and high-quality diet to maintain fin health and color vibrancy.

Recommended Foods

• Premium guppy flakes or micro-pellets

• Live/Frozen foods:

  • Baby brine shrimp

  • Daphnia

  • Bloodworms (occasionally)

• Plant-based supplements:

  • Spirulina

  • Algae wafers (small portions)

Feeding Schedule:
2–3 small meals per day

A healthy diet prevents fin thinning and color fading.

Compatibility & Tank Mates

Best Tank Mates

• Other fancy guppies

• Platies and mollies

• Peaceful tetras

• Corydoras

• Snails and shrimp

Avoid

• Fin-nippers (barbs, aggressive tetras)

• Fast or dominant species

Halfmoon Guppies thrive in peaceful, aesthetic community tanks.

Breeding & Genetics

Breeding Characteristics

• Livebearer

• Gestation: 25–30 days

• Fry count: 20–40 per spawn

Breeding Challenges

• Maintaining true 180° tail spread

• Preserving symmetry and fin strength

• Avoiding fin degeneration

Selective breeding is required—only the best males and females should be paired.

Health & Care

Common Issues

• Fin rot

• Tail tearing

• Stress-related color loss

Prevention

• Weekly water changes (20–30%)

• Stable temperature

• Gentle filtration

• High-quality diet

Healthy Halfmoon Guppies hold their tails wide even when resting.

Lifespan

Average lifespan: 2–3 years

With excellent care, some may live longer while maintaining show quality.