Three-Lined Pencilfish – A Delicate and Elegant Addition to Your Aquarium
(Nannostomus unifasciatus)

The Three-Lined Pencilfish (Nannostomus unifasciatus) is a peaceful and strikingly beautiful species that brings elegance and color to any freshwater tank. Known for its slender, pencil-like body and distinctive three black lines running across its body, this fish is a wonderful choice for aquarists who enjoy smaller, non-aggressive species. Native to South America, the Three-Lined Pencilfish is a delight to watch, especially as it swims in small schools, darting through the water with grace and precision.

Key Features:

• Elegant Appearance: Long, slender body with three black vertical stripes running along its body

• Small Size: Reaches a maximum size of about 4 cm (1.5 inches), making it an excellent choice for nano and small community tanks

• Active and Peaceful: Known for its peaceful nature and schooling behavior, best kept in groups of 6 or more

• Colorful: Features a yellow-orange hue around the belly, making it a lovely contrast to the dark stripes

• Hardy and Adaptable: Well-suited for a variety of water conditions, as long as the water parameters are stable

Tank Requirements:

• Minimum tank size: 40 liters (10 gallons) for a small group

• Temperature: 24°C–28°C (75°F–82°F)

• pH: 6.0–7.5 (slightly acidic to neutral)

• Prefers soft to medium substrate like fine gravel or sand, and a well-planted tank with some open swimming space

• Moderate filtration and gentle water flow will mimic its natural slow-moving river habitats

• Provides plenty of hiding spots through plants, driftwood, or rocks to give the fish a sense of security

Compatibility:

• Schooling Species: Best kept in groups of at least 6 individuals, as they feel safer and more comfortable in larger groups

• Ideal tankmates include small, peaceful fish like tetras, rasboras, guppies, and small Corydoras catfish

• Avoid keeping with larger or aggressive species, as the Pencilfish may be intimidated by such tankmates

• Can be kept with shrimp, but be cautious with very small or delicate shrimp species, as the Pencilfish may nip at them if not properly fed

Feeding Tips:

• Omnivorous—feeds on a variety of small foods, both live and frozen

• Enjoys a diet of brine shrimp, daphnia, and small worms like bloodworms

• Will also accept high-quality flakes and micro-pellets, especially those designed for small fish

• Feed 2–3 times a day in small portions, ensuring that the fish are not overfed and the water remains clean

• Occasionally supplement with finely chopped vegetables or blanched greens like spinach

Why Choose the Three-Lined Pencilfish?
The Three-Lined Pencilfish is a fantastic choice for aquarists seeking a small, peaceful, and elegant fish that adds a dash of color and charm to their aquarium. Its schooling behavior, peaceful nature, and attractive appearance make it a perfect addition to community tanks. Whether you're a beginner or an experienced hobbyist, this delightful fish is sure to captivate you and your visitors alike.