Red Beckfords Pencilfish (Nannostomus beckfordi)

Scientific name: Nannostomus beckfordi
common name: Beckford’s pencilfish

Quick Overview

• Family: Lebiasinidae
• Adult size: 5–6 cm (2–2.5 in)
• Lifespan: 4–6 years
• Temperament: Peaceful, mildly territorial males
• Difficulty: Easy–moderate

Identification & Appearance

• Slender, elongated “pencil” body shape
• Gold to bronze body with distinct horizontal dark stripe running nose to tail
• Fins often show orange-red highlights, especially in males
• At night or when stressed, the stripe may fade (normal behavior)

Sexual dimorphism:

• Males are slimmer, more colorful, and may spar gently
• Females are slightly larger and rounder

Natural Origin & Habitat

• Native to Guyana, Suriname, and the Amazon basin
• Found in:
  • Slow-moving streams
  • Flooded forest margins
  • Soft, tannin-stained waters
• Often congregate under overhanging vegetation

Aquarium Care

Tank Size & Setup

• Minimum tank: 20 gallons (long tanks preferred)
• Best kept in groups of 6–10+
• Ideal setup:
  • Dense planting along sides and back
  • Open swimming space in the center
  • Driftwood and floating plants
  • Dim to moderate lighting

Water Parameters

• Temperature: 24–28 °C (75–82 °F)
• pH: 5.5–7.0
• Hardness: Soft to moderately soft (2–10 dGH)
• Appreciates slightly tinted water but adapts well to clear tanks

Behavior & Compatibility

• Generally peaceful and calm
• Males establish small territories but rarely cause harm
• Excellent community fish for peaceful South American setups

Good tankmates:

• Small tetras
• Corydoras
• Apistogramma
• Dwarf cichlids
• Otocinclus

Avoid:

• Aggressive or fin‑nipping species
• Large, fast, or boisterous fish

Diet

• Omnivorous with insectivorous preference
• Accepts:
  • Flakes and micro pellets
  • Frozen foods (bloodworms, brine shrimp)
  • Live foods enhance color and condition
• Feed small amounts 1–2× daily

Breeding (Summary)

• Egg scatterers; no parental care
• Dense plants or spawning mops required
• Adults may eat eggs
• Fry are tiny and need infusoria or powdered fry food initially