Least pencilfish

Care at a glance

Overview

The least pencilfish is a tiny, peaceful pencilfish that lives in the midwater in a loose school. Its small size and soft-water needs put it a step beyond a beginner's fish.

Caring for the least pencilfish

Keep least pencilfish in a school of ten or so, in a tank of at least 11 gal (40 L). Small numbers leave them nervous and washed out, while a proper school stays colored up and active.

A mature, densely planted tank with driftwood, leaf litter and a dark substrate suits them. Keep the filtration gentle and give them plenty of cover to dart into. Dim light brings out their best color and keeps them at ease.

Give them soft, acidic water at 75 to 82°F (24 to 28°C) and a pH of 5.0 to 6.5. They are micro-predators that take tiny invertebrates and zooplankton, and their mouths are small. Feed fine foods such as crushed flake, micro pellets, cyclops, daphnia and freshly hatched brine shrimp.

Least pencilfish are peaceful and suit a quiet community of other small, gentle fish. Avoid anything big enough to eat them or bustle them aside at feeding time. They scatter eggs among fine-leaved plants, but spawning is little documented for this species in the aquarium.

Good to know

The least pencilfish belongs to the pencilfish family Lebiasinidae and is also known as the minimus pencilfish. It is slender and marked with dark lengthwise lines.

In the wild

The least pencilfish comes from the tea-colored forest creeks of Guyana. These are soft, acidic waters, shaded by overhanging growth.

Common questions

Related species

• 

  Barred pencilfish

  Nannostomus espei

  1.2 in (3 cm) · 15 gal (55 L)

  1.2 in (3 cm)15 gal (55 L)72–82°F (22–28°C)

• 

  Coral red pencilfish

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  1.2 in (3 cm)15 gal (55 L)75–82°F (24–28°C)

• 

  Dwarf pencilfish

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• 

  Three-lined pencilfish

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  1.3 in (3.3 cm) · 15 gal (55 L)

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• 

  Hockeystick pencilfish

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• 

  Twostripe pencilfish

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  1.4 in (3.5 cm) · 12 gal (45 L)

  1.4 in (3.5 cm)12 gal (45 L)75–82°F (24–28°C)