Beckford's Pencilfish

Nannostomus beckfordi

Characins

A peaceful, slender schooling fish native to the sluggish rivers and swamps of South America. They are famous for the males' harmless but spectacular lateral sparring displays. They require heavily planted aquariums with gentle flow and make excellent tank mates for other peaceful, soft-water species. A tight-fitting lid is essential as they are known to be proficient jumpers.

At a Glance

Adult Size6.5 cm
Body ShapeFusiform
Growth RateModerate
TemperamentPeaceful
Water TypeFreshwater Only
Flow PreferenceLow
Waste OutputLow
StockingSchool of 6+

Tank Requirements

Minimum Volume60 L
Minimum Length60 cm
FlowLow
Water TypeFreshwater Only
Must-Haves in the Tank
Plants - Densely coveredPlants - FloatingLeaf Litter/Blackwater

Water Parameters

Temperature2228°C
pH57.5
Hardness115 dGH

Temperament & Compatibility

Aggression LevelPeaceful
2/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least6 fish
Max per TankNo limit
Can Live Alone?No — needs a group
Behavior Traits
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Shy / Slow Moving (Easily Stressed)

Available Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Standard

The standard form available in the hobby. Best kept in groups of 6 or more (ideally 10+) with a mix of males and females to encourage natural sparring displays and vibrant coloration.

Differs in 1 trait from base species

Also known as: Golden Pencilfish, Wild Type

Behavior Traits
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Shy / Slow Moving (Easily Stressed)

Beckford's Pencilfish Care Guide Summary

The Beckford's Pencilfish, scientifically known as Nannostomus beckfordi, belongs to the Characins family group. Adults reach a maximum size of approximately 6.5 cm and have a fusiform body shape with a moderate growth rate. Classified as peaceful, this species primarily occupies the surface and mid-level zones of the aquarium and produces a low level of biological waste.

To thrive, the Beckford's Pencilfish requires a freshwater only aquarium with a minimum volume of 60 litres and a tank length of at least 60 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 57.5 and a general hardness of 115 dGH. A low water flow is preferred.

Due to its specialist needs, the Beckford's Pencilfish is best suited for fishkeepers who can provide a carefully planned setup. The Beckford's Pencilfish is typically available in one standard form.

Beckford's Pencilfish Habitat Setup

When setting up an aquarium for the Beckford's Pencilfish, a low water flow best suits their natural preferences. Because this species occupies the surface and mid-level zones, the aquarium layout should prioritise adequate surface area with floating cover to make them feel secure near the waterline and open swimming space in the centre of the tank for free movement. Useful additions include leaf litter or blackwater tannins to replicate their natural soft-water habitat, dense planting to provide cover, break sightlines, and reduce stress, and floating plants to diffuse overhead light and create shaded areas. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.

Beckford's Pencilfish Compatibility Notes

Classified as peaceful, the Beckford's Pencilfish is a schooling species that feels most secure in a sizeable group, where natural shoaling behaviour reduces stress and brings out their best colours. Selecting tankmates that favour different water layers from the surface and mid-level zones can help reduce competition and territorial overlap.

Frequently Asked Questions About Beckford's Pencilfish

How big does Beckford's Pencilfish get?+
Beckford's Pencilfish (Nannostomus beckfordi) typically reaches a maximum adult size of approximately 6.5 cm. They have a fusiform body shape and a moderate growth rate.
What tank size does Beckford's Pencilfish need?+
A minimum aquarium volume of 60 litres and a tank length of at least 60 cm are recommended for Beckford's Pencilfish. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Beckford's Pencilfish need?+
Beckford's Pencilfish thrives in freshwater only conditions with a temperature range of 22–28°C, a pH between 5 and 7.5, and a general hardness of 1–15 dGH. A low water flow is preferred.
Is Beckford's Pencilfish peaceful or aggressive?+
Beckford's Pencilfish is classified as peaceful with an aggression score of 2 out of 10. They are generally well-suited to peaceful community tanks.
How many Beckford's Pencilfish should be kept together?+
Beckford's Pencilfish is a schooling species and should be kept in groups of at least 6. Larger groups help distribute aggression and encourage natural schooling behaviour.
Does Beckford's Pencilfish have any special tank requirements?+
Yes. Beckford's Pencilfish benefits from plants - densely covered, plants - floating, and leaf litter/blackwater in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Beckford's Pencilfish need a lid on the tank?+
Yes. Beckford's Pencilfish is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.

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