Description
The golden pencilfish is the species on which the genus Nannostomus was founded and the most widely spread. It reaches 6.5 cm and carries a silvery band along the flank, with a reddish edge above and a blackish one below, and a red-tinged tail. It occurs in the Guianas, the eastern Amazon basin and the Venezuelan Orinoco, and varies so much from one population to another that several forms were taken for different species.
It is the least demanding of the genus. A good part of what is sold comes from farms.
Behavior
Relatively peaceful, although it does not compete with boisterous or much larger fish. In a group of ten or more it is calmer and the squabbles are spread among all.
It lives well with peaceful characids of its size, corydoras and small loricariids, rasboras, barbs and small anabantoids. Because it moves between the middle and upper zones it works as a dither fish for dwarf cichlids, and it rarely preys on fry.
Avoid housing it with hatchetfish in small tanks or with boisterous companions.
Habitat
Nannostomus beckfordi inhabits sluggish creeks, minor rivers and boggy ground, especially where aquatic plants grow thick and there is sunken wood and fallen leaves.
It asks for a heavily planted tank on a dark substrate, with floaters and wood and minimal current.
Pez lápiz dorado is a schooling species, which means that in the wild it lives and moves in large, coordinated groups.
Keep at least 6 individuals so they feel comfortable and their stress level stays low.
Details
🌊 Water parameters
🐠 Minimum tank size
Breeding
It is a free spawner with no parental care. In a mature tank it spawns often and fry appear without intervention; to raise more, a separate, very dark tank is set up with a mesh on the bottom, marbles or fine moss, and slightly acidic water.
Males have more intense colours and a curved rear edge to the anal fin, straight in females, which are also rounder.
Diet
A micropredator that eats tiny invertebrates and zooplankton.
- Staple: small-sized dry food.
- Supplement: brine shrimp nauplii, moina or grindal worm, live or frozen, daily.
What about your tank?
Enter your tank's values to see only the compatible species that fit them. Litres apply to fish.
Compatible fish
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 7–8 and 26–27 °C.
They share water: pH 6–7.5 and 22–27 °C.
They share water: pH 6–7.5 and 22–27 °C.
They share water: pH 6–7.5 and 22–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 5.5–7 and 24–27 °C.
They share water: pH 6–8 and 21–26 °C.
They share water: pH 5.5–8 and 21–27 °C.
They share water: pH 6–8 and 24–27 °C.
They share water: pH 6–7.5 and 25–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 6.5–8 and 24–26 °C.
They share water: pH 6–8 and 22–26 °C.
They share water: pH 6–7.5 and 21–25 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 6.5–7.5 and 21–24 °C.
They share water: pH 5–7 and 27 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 7–8 and 21–27 °C.
They share water: pH 6.5–8 and 22–27 °C.
They share water: pH 6–7.5 and 25–27 °C.
They share water: pH 6–8 and 22–27 °C.
They share water: pH 6–7.5 and 22–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 5.5–7 and 24–27 °C.
They share water: pH 7.5–8 and 24–27 °C.
They share water: pH 7.5–8 and 24–27 °C.
They share water: pH 5.5–7 and 21–26 °C.
They share water: pH 5–6.5 and 23–27 °C.
They share water: pH 6.5–7.2 and 22–26 °C.
They share water: pH 6–7.5 and 21–26 °C.
They share water: pH 6–8 and 21–22 °C.
They share water: pH 6.5–8 and 21–24 °C.
They share water: pH 5–7.5 and 22–27 °C.
They share water: pH 5–7 and 23–27 °C.
They share water: pH 5–7.5 and 22–27 °C.
They share water: pH 7–8 and 22–27 °C.
They share water: pH 5.5–7 and 26–27 °C.
They share water: pH 5.5–7 and 22–26 °C.
They share water: pH 6.5–7.5 and 22–26 °C.
They share water: pH 5–6.5 and 24–27 °C.
They share water: pH 5.5–7 and 23–27 °C.
They share water: pH 5–8 and 23–27 °C.
They share water: pH 5.5–7.5 and 23–27 °C.
They share water: pH 5.5–8 and 24–27 °C.
They share water: pH 6–7.5 and 21–26 °C.
They share water: pH 5.5–7.5 and 23–27 °C.
They share water: pH 5.5–7.5 and 22–27 °C.
They share water: pH 7–8 and 22–27 °C.
Compatible invertebrates
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.
They share water: pH 7–8 and 21–27 °C.
They share water: pH 5.5–6.5 and 21–24 °C.
They share water: pH 6.5–7.5 and 22–27 °C.
They share water: pH 7–8 and 21–25 °C.
They share water: pH 7.5–8 and 24–27 °C.
They share water: pH 7–8 and 22–27 °C.
They share water: pH 7.5–8 and 26–27 °C.
They share water: pH 7–8 and 22–27 °C.
They share water: pH 6.5–7.5 and 21–26 °C.
They share water: pH 5.8–6.8 and 21–24 °C.
They share water: pH 5.8–6.8 and 21–24 °C.
They share water: pH 6.5–7.5 and 21–27 °C.
They share water: pH 7.5–8 and 27 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 7–8 and 21–27 °C.
They share water: pH 6.5–7.5 and 21–26 °C.
They share water: pH 6.5–7.5 and 21–26 °C.
They share water: pH 6.5–7.5 and 21–26 °C.
They share water: pH 6.5–7.5 and 21–26 °C.
They share water: pH 6.5–7.5 and 21–26 °C.
They share water: pH 6.5–7.5 and 21–26 °C.
They share water: pH 7–8 and 22–27 °C.
They share water: pH 7–8 and 22–27 °C.
They share water: pH 6.5–8 and 21–27 °C.
They share water: pH 7–8 and 21–27 °C.
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They share water: pH 7–8 and 21–27 °C.
Sources
- FishBaseFroese, R. and D. Pauly. Editors. 2026. FishBase. World Wide Web electronic publication.
- Seriously FishSeriously Fish. Nannostomus beckfordi. Ficha de especie; consultada 2026-10.
Water: FishBase gives pH 6-8, 5-19 dH and 24-26 °C; Seriously Fish, pH 5-8, 1-15 dGH and 21-27 °C. The profile uses the widest range. Size: 6.5 cm SL in both sources.
Litres per fish and minimum tank height and depth: the profile's own judgement. Seriously Fish gives only the tank base and FishBase gives no tank sizes.
Plan your next aquarium
Is this fish right for you? Plan a suitable aquarium before setting it up.