Red-tailed Pencilfish

Nannostomus rubrocaudatus

FishFreshwater

Nannostomus rubrocaudatus reaches about 3 cm. Its elongated, slender body is typical of pencilfishes. The caudal fin is intense red, contrasting with the silvery body. A thin black horizontal line runs along the flank. It lives in schools and enjoys soft, acidic water. Its behavior is very peaceful, making it an excellent community fish. In the aquarium, it often stays in mid-water and is active.

Recommended parameters

ParameterRecommended range
Temperature23–28
pH5.5–7
GH1–10
KH1–5
NO₃≤ 20
PO₄≤ 0.5

Care

Difficulty2/5
Dietcarnivore
Min. tank60 L
Min. group6
Adult size3 cm
Lifespan4 ans
Temperamentpeaceful

Care notes

Keep temperature at 23-28°C, pH 5.5-7.0, GH 1-10. A minimum 60-liter tank is recommended for a group of 6. Water should be well-filtered with moderate flow. Provide a varied diet: micro-worms, brine shrimp, daphnia, and fine flakes. Floating plants and dense vegetation are appreciated. Avoid overly active or large tankmates. Compatible with other small tetras, rasboras, and corydoras.