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🐟 Molly Fish (Poecilia sphenops)

The Molly Fish is a versatile livebearer available in an incredible variety of colors and fin types. From the classic black molly to dramatic sailfin varieties, mollies are hardy, peaceful, and make excellent community fish. They're unique among freshwater fish in their ability to tolerate brackish and even full marine conditions.

📋 Quick Facts

Scientific NamePoecilia sphenops and related species
Adult Size3-5 inches (7.5-12.5 cm)
Minimum Tank20 gallons (75 liters)
TemperamentPeaceful
DifficultyBeginner
Lifespan3-5 years
OriginCentral America, Mexico

🌟 Popular Varieties

  • Black Molly - Solid black, most popular
  • Dalmatian Molly - White with black spots
  • Sailfin Molly - Large dramatic dorsal fin
  • Balloon Molly - Rounded body shape
  • Lyretail Molly - Forked tail fin
  • Gold/Orange Molly - Bright coloration

âš ī¸ Important Considerations

  • Prefer hard, alkaline water - May struggle in soft water
  • Prolific breeders - Livebearers that breed constantly
  • Males harass females - Keep 2-3 females per male
  • Can go brackish - Salt can help health

🏠 Tank Requirements

  • Tank Size: 20 gallons minimum (sailfins need 30+)
  • Plants: Appreciate live plants
  • Space: Active swimmers need room
  • Salt: 1 tsp/gallon can benefit health (optional)

Water Parameters

Temperature72-82°F (22-28°C)
pH7.5-8.5 (prefer alkaline)
Hardness15-30 dGH (prefer hard water)
Ammonia/Nitrite0 ppm
Nitrate<40 ppm

đŸŊī¸ Diet & Feeding

Omnivores with herbivorous tendencies.

  • Quality flakes - Staple
  • Spirulina flakes/wafers - Important for health
  • Blanched vegetables - Zucchini, peas, spinach
  • Frozen foods - Occasional protein
  • Algae - Will graze naturally

Feed 2-3 times daily. Include vegetable matter regularly.

🐟 Compatibility

Good Tankmates

  • Other livebearers (guppies, platies, swordtails)
  • Corydoras
  • Peaceful tetras
  • Rainbowfish
  • Peaceful barbs
  • Snails

Avoid

  • Fin nippers - Especially with sailfin/lyretail
  • Aggressive fish
  • Fish requiring soft acidic water

đŸ‘ļ Breeding

  • Livebearers - Give birth to live fry
  • Gestation: 60-70 days
  • Fry per batch: 20-100
  • Fry survival: Provide plants for hiding
  • Females store sperm - Multiple batches from one mating

💡 Tips for Success

  • Keep in hard, alkaline water
  • Consider adding aquarium salt
  • Maintain 2-3 females per male
  • Include vegetable matter in diet
  • Have a plan for fry

📚 Summary

Mollies are hardy, colorful livebearers that thrive in harder water conditions where many fish struggle. Their variety of colors and fin types, peaceful nature, and ease of breeding make them excellent community fish for beginners and experienced aquarists alike.