Golden pencilfish (Nannostomus beckfordi) care guide

Group
Freshwater fish
Other names
Beckford's pencilfish, Brown pencilfish
Family
Lebiasinidae (pencilfishes)
Origin
Northern South America: Guyana, Suriname, French Guiana, Venezuela and northern Brazil, in the Amazon, Negro, Orinoco and Demerara systems.
Water
freshwater
Maximum size
6.5 cm
Temperature
21–27°C
pH
5–8
Hardness
Very soft to fairly hard, 1–15 dGH
Minimum tank
41 litres
Care level
beginner
Temperament
peaceful

Care

Golden pencilfish are sociable and are best kept in a group of 10 or more; in a bigger group the males show off to each other and colour up well. A tank with a base of at least 45 × 30 cm (around 41 litres) is enough for a small group. Give them a well-planted tank with some floating plants, driftwood and a darker substrate so they feel secure. Males are mildly territorial within the group, but squabbles are harmless. This is one of the more adaptable pencilfish: it is happy at about 21–27 °C with a pH anywhere from 5 to 8 and soft to fairly hard water, although wild-caught fish do better at the soft, acidic end. Keep the water clean and stable. Identification: a slim fish with a strong dark stripe along the flank and a gold-to-red band above it; males are brighter, with red in the fins, and the rear edge of the male's anal fin is curved rather than straight. Like other pencilfish it has no adipose fin and switches to a barred camouflage pattern at night. Colour varies from place to place and several red and gold forms are sold. The name 'brown pencilfish' is also used for N. eques, so check the scientific name when buying. It has been exported for the aquarium hobby since about 1910 and is widely available, mostly as captive-bred stock. FishBase lists it as Least Concern on the IUCN Red List. Sources: Seriously Fish (seriouslyfish.com/species/nannostomus-beckfordi/); FishBase (fishbase.se/summary/Nannostomus-beckfordi.html); Wikipedia (en.wikipedia.org/wiki/Nannostomusbeckfordi). Checked October 2026.

Diet

A micropredator that picks off small invertebrates in the wild. It will take good-quality small dried foods, but offer small live or frozen foods every day too, such as Artemia nauplii, Moina and grindal worm, to keep it in good colour and condition.

Breeding

An egg-scatterer that gives no parental care. Pairs spawn side by side, laying small batches of eggs among fine-leaved plants, up to about 200 in total. Use a separate tank with fine-leaved plants or a spawning mop and soft, slightly acidic water, and remove the adults afterwards as they will eat the eggs. Eggs hatch in about 30–40 hours and the fry swim freely a few days later. Start them on very fine foods such as Paramecium or a fine powdered food, moving on to Artemia nauplii as they grow.

Compatibility and tank mates

Peaceful and a good community fish, but it will not compete with boisterous or greedy tankmates. Keep with similar-sized peaceful fish such as small tetras, rasboras, Corydoras and other small catfish. It also makes a good dither fish for dwarf cichlids such as Apistogramma.

Last updated 5 October 2026. Community-edited care guide on Aquatic-Auctions.

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