科: Lebiasinidae
Dwarf Pencilfish（Nannostomus marginatus）は鳉脂鲤科に分類される淡水魚で、南米に分布する。成魚は約 2.6–3.9 cm、適水温 24–26 °C。
A Lebiasinidae species native to South America: Nannostomus marginatus lives bottom-dwelling over warm freshwater streams and lakes. Peaceful mid-water shoaler; confidence comes in numbers. Adults reach 2.6–3.9 cm. It is one of the aquarium-kept Nannostomus species we profile, alongside Nannostomus beckfordi, Nannostomus eques, Nannostomus harrisoni.
難易度：中級。Peaceful mid-water shoaler; confidence comes in numbers。
24–26 °C が目安。急変を避け、Stable temperature matching the species origin。
成魚 2.6–3.9 cm 前後。Bottom-dwellingのため 25 L 以上の水槽を推奨。
Small omnivore; quality flakes and small frozen foods。人工飼料に冷凍餌を組み合わせて。
可能。Peaceful mid-water shoaler; confidence comes in numbers。おすすめ：Other small peaceful tetras and rasboras — Form a mixed, calm mid-water mass。Single-species isolation — A lone tetra is a stressed tetraとの混泳は避ける。
南米のWarm freshwater streams and lakesが生息地。
換水・メンテ時はふたを推奨。
繁殖：Typical egg-scattering characin; adults eat the eggs。Subtle external differences。