Golden Pencilfish
Nannostomus beckfordi
Also sold as Beckford's pencilfish · Red beckfordi pencilfish · Beckfordi
Synonyms Beckfordi pencilfish · Red pencilfish
Golden Pencilfish (Nannostomus beckfordi) is a peaceful freshwater fish that reaches about 6.5 cm (2.6 in) and swims near the surface in a shoal. It wants 70–81°F (21–27°C) and pH 5–8, is kept in groups of 10 or more, and needs a tank of at least 41 L (11 gal).
At a glance
| Type | Fish |
|---|---|
| Adult size | 6.5 cm (2.6 in) |
| Minimum tank | 41 L (11 gal) |
| Group size | 10 or more |
| Temperature | 70–81°F (21–27°C) |
| pH | 5–8 |
| Temperament | Peaceful |
| Lifespan | 3–5 years |
| Eats shrimp | Shrimplets only |
Before it goes in
- Golden Pencilfish needs at least 41 L (11 gal). The smallest size in this library that clears that is the 15 Gallon.
- Keep 10 or more. Below that it hides, colours down and is far more likely to be picked on.
- Adult shrimp are safe; shrimplets will be eaten, so a shrimp colony will not grow in the same tank.
- It is the wrong size to share a tank with Goldfish, Axolotl and Oscar: it ends up as food.
- It holds at 70–81°F (21–27°C). That shares a window with Betta and Cherry Shrimp, but not with Discus.
- A group of 10 takes up roughly 177% of what a 15 Gallon will comfortably hold, so plan the rest of the stock around it.
What tank size does it need?
At least 41 L (11 gal). The smallest size here that clears it is the 15 Gallon.
How many should I keep?
10 or more. Fewer than that and it spends its time hiding instead of out in the open.
Will it eat shrimp?
Adults are safe, shrimplets are not. You can keep shrimp with it; you just will not get a growing colony.
What water does it want?
70–81°F (21–27°C), pH 5–8.
How long does it live?
3–5 years in a tank that suits it. That is how long you are signing up for.
Good tank mates
- Tank mates from this library that share its temperature window, are peaceful and eat neither it nor its young: Cherry Shrimp, Bristlenose Pleco, Celestial Pearl Danio, Molly and Otocinclus.
- Plants that hold up with it: Hygrophila corymbosa 'Siamensis', Water Sprite, Anubias nana 'Petite' and Cryptocoryne wendtii.
Often compared with
| Golden Pencilfish | Golden Dwarf Acara | Golden Wonder Killifish | |
|---|---|---|---|
| Adult size | 6.5 cm | 7.6 cm | 10 cm |
| Min tank | 41 L | 52 L | 90 L |
| Group | 10+ | 1+ | 1+ |
| Temperature | 70–81°F (21–27°C) | 72–81°F (22–27°C) | 72–77°F (22–25°C) |
| Eats shrimp | Shrimplets only | Yes | Yes |
More livestock
Sources (5) · checked Sep 2026
- What it eats, Mature tankaquariumcoop.com
- What it eatsaquariumstoredepot.com
- What it eatsseriouslyfish.com
- riverparkaquatics.co.uk
- tropicalfishandaquariums.com