Dwarf Pencil Fish Nannostomus Marginatus 3cm

Overview

The Dwarf Pencilfish (Nannostomus marginatus) is a tiny, slender fish with three crisp black stripes over a golden body and red-tinted fins. It comes from sluggish blackwater tributaries and swamps across Guyana, Suriname and the Amazon basin. Suited to nano tanks, planted aquascapes and peaceful communities of small fish.

• Adult Size: Around 2.5–3 cm (1–1.2 in); females stockier
• Lifespan: 3–5 years

Origin

• Native to: Guyana, Suriname, Amazon basin of Peru, Colombia, Brazil
• Habitat: Sluggish blackwater streams with dense plants and leaf litter

Feeding

• Diet: Omnivorous micropredator
• Preferred Foods: Artemia nauplii, Moina, Daphnia, grindal worm, micro pellets, crushed flake
• Feeding Habits: Small feeds twice daily; foods must be tiny

Tank Mates

• Best with: Small tetras, rasboras, Corydoras, Apistogramma, dwarf shrimp
• Avoid: Large, boisterous or greedy fish, fin nippers

Aggression & Behaviour

• Temperament: Very peaceful, timid
• Territoriality: None; keep in groups of ten or more

Experience Level

• Difficulty: Intermediate
• Challenges: Needs tiny foods, soft water and quiet company

Water Parameters

• Water Type: Freshwater, soft and acidic, blackwater
• Temperature: 22–28°C (72–82°F)
• pH: 4.0–7.0
• Hardness: 1–10 dGH
• Flow: Slow
• Tank Size: Minimum 40 litres for a group of ten

Final Notes

Its small size and shy nature mean it is easily outcompeted, so keep it in a heavily planted tank with dark substrate, leaf litter and gentle filtration. Several geographic colour forms exist and all switch to a cryptic barred pattern at night, which is normal. It can be bred in a mature planted tank, scattering eggs among fine-leaved plants. A group of ten or more makes a charming, ever-active shoal.