Dwarf Pencilfish (Nannostomus marginatus)

Family: Lebiasinidae

Dwarf Pencilfish — a Lebiasinidae from 南美洲, peaceful mid-water shoaler; confidence comes in numbers. Reaches 2.6–3.9 cm; groups of 8 minimum; more is visibly better. 24–26 °C.

Care parameters

Water temperature
24–26 °C
pH
5.8–7.5
GH hardness
5–19 dGH
Adult length
2.6–3.9 cm
Minimum tank
25 L
Water layer
Bottom-dwelling
Difficulty
Moderate
Temperament
Peaceful mid-water shoaler; confidence comes in numbers
Origin
南美洲

Species overview

Lebiasinidae species Nannostomus marginatus comes from 南美洲. A mid-water shoaler whose colour and courage arrive together, with the group. It lives on the bottom. Adults reach 2.6–3.9 cm. Groups of 8 minimum; more is visibly better. Dark substrate, gentle light, big school — the three levers for this fish. Maintain 24–26 °C at pH 5.8–7.5. Undemanding once its core needs are met.

Native biotope

Habitat
Warm freshwater streams and lakes
Flow
Still to gentle current
Dissolved O₂
Moderate oxygen levels

Aquascape & hardware

Substrate
Fine sand and gravel
Hardscape
Driftwood and smooth stones
Plants
Hardy common aquarium plants

Temperament, diet & tankmates

Schooling
Groups of 8 minimum; more is visibly better
Diet
Small omnivore; quality flakes and small frozen foods
Recommended tankmates
  • Other small peaceful tetras and rasboras — Form a mixed, calm mid-water mass
Avoid keeping with
  • Single-species isolation — A lone tetra is a stressed tetra

Breeding & notes

Sexual dimorphism
Subtle external differences
Breeding method
Typical egg-scattering characin; adults eat the eggs