Anduzei pencilfish

Nannostomus anduzei

Also known as Dwarf ruby pencilfish, Colombian dwarf pencilfish

FreshwaterFish

Anduzei pencilfish (Nannostomus anduzei) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 75–82°F (24–28°C)
pH: 4.5–6.5
Adult size: 0.7 in (1.9 cm)
Minimum tank: 5 gal (20 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Difficult
Breeding: No record
Rarity: Rare
Origin: Upper Orinoco and Casiquiare blackwaters, Venezuela
Family: Lebiasinidae

Overview

One of the smallest fish in the hobby, this pencilfish is a delicate schooler best kept in a group of a dozen or more so it feels secure and stays in view. It swims in the midwater of a quiet, mature tank and is easily lost among anything bigger, so keep it either on its own or with only the tiniest, gentlest companions. Because its mouth is minute, feed dust-fine foods: infusoria and similar micro foods for young fish, then microworm, freshly hatched brine shrimp and finely crushed flake. It needs stable, soft, acidic blackwater and gentle sponge-filter flow, in a densely planted nano tank of around 20 liters.

In the wild

The anduzei pencilfish comes from slow, plant-filled blackwaters of the upper Orinoco and Casiquiare in Venezuela. Recreate its home with warm water, about 24 to 28 C, and soft, acidic conditions around pH 4.5 to 6.5. A mature tank with dark substrate, driftwood, leaf litter and dense planting, softly lit and gently filtered, keeps this tiny fish settled; stability matters more to it than any single number.

Good to know

Nannostomus anduzei belongs to the pencilfish family Lebiasinidae and is the smallest member of its genus, a slim gold fish with fine dark striping and a red-touched tail. It feeds on tiny invertebrates and needs correspondingly small foods in the aquarium. Spawning is barely documented for it, as with many of the rarely bred dwarf pencilfish. It is delicate and easily outcompeted, which is why it is rated a fish for experienced keepers.

Did you know

It is the smallest pencilfish known and one of the tiniest characins of all, becoming a breeding adult at little more than a centimeter long and never much exceeding a centimeter and a half.