Fish
Dwarf Pencilfish
Nannostomus marginatus
Origin: Nannostomus marginatus comes from northern South America — Guyana, Suriname, and the lower Amazon. It inhabits small shaded streams and backwaters with soft, acidic water and dense vegetation.
Also known as: Nannostomus marginatus
Fact sheet
- Size
- 4 cm
- Lifespan
- 4 years
- Minimum tank size
- 40 L
- Temperature
- 22–28 °C
- pH
- 5–7
- Hardness GH
- 1–10 °dH
- Temperament
- Peaceful
- Social behavior
- Schooling
- Group size
- 8+ individuals
- Swimming zone
- Middle
- Diet
- Omnivore
- Jumps out
- No
- Eats plants
- No
Overview
The dwarf pencilfish is the smallest and one of the most ornate pencilfish, reaching only 3.5 cm. Three dark longitudinal stripes run along the body, and the fins carry bright red areas. Despite its tiny size the colour is very contrasting. It is a peaceful schooling nano fish kept in a tight group in a planted tank with soft water. Its tiny mouth requires small food. An excellent choice for nano aquariums and biotope layouts.
Appearance
The body is stockier than in other pencilfish, up to 3.5 cm long. Three clear dark longitudinal stripes run along the golden-beige body; the fins carry bright red areas, especially in males. Males are brighter and slimmer, females fuller. It is very contrasting for its size.
Care
A tank of at least 40 L, densely planted, with calm soft water. Temperature 22–28 °C, pH 5.0–7.0, hardness GH 1–10. Clean water, gentle flow, and regular water changes are needed. Dark substrate and diffuse light bring out the colour.
Feeding
An omnivore with a very small mouth. Food must be small: micro-pellets, crushed flakes, and live or frozen cyclops, brine shrimp nauplii, and micro-worm. Feed once or twice daily in small portions.
Compatibility
A very peaceful schooling nano fish. Ideal with small rasboras, microrasboras, dwarf tetras, corydoras, and shrimp. Any large or fast fish are unsuitable. Keep in groups of 8–10 or more.
Breeding
An egg-layer. It scatters small eggs among moss and fine-leaved plants; remove the adults. The tiny fry need infusoria and 'green water' — the hardest rearing stage.
Fun facts
Marginatus is the smallest of the pencilfish. The species name marginatus ('margined') comes from the bright red edging of the fins. Despite its size its colour is one of the most contrasting in the genus.