Nitidus Pencilfish (Nannostomus nitidus) Breeding Guide

Breeding Nannostomus nitidus: an egg-scattering free spawner from Pará, Brazil, that spawns in dim light over mesh or fine plants, with fry raised on infusoria and brine shrimp.

Overview

Nannostomus nitidus is a small pencilfish recorded from the Igarapé Candiru-Mirim, Rio Capim, in Pará, Brazil, reaching about 30-35 mm standard length (Seriously Fish). Seriously Fish describes it as an egg-scattering free spawner exhibiting no parental care.

Sexing

According to Seriously Fish, adult males are usually slimmer and more intensely patterned than females, and the male's anal fin is slightly modified with thicker rays.

Conditioning

Seriously Fish recommends conditioning the adults together in a separate, smaller aquarium. Slightly acidic to neutral water is advised for spawning, with temperature toward the upper end of the 23-28 degrees C range; the spawning tank should be very dimly lit.

Breeding Setup

Seriously Fish suggests a base that allows eggs through but blocks the adults, such as a mesh, plastic grass-type matting or glass marbles; alternatively a fine-leaved plant such as Taxiphyllum or spawning mops work well. An air-powered sponge filter or air stone provides gentle oxygenation. Introduce a single pair, or a group of one or two males with several females.

Spawning Behavior & Trigger

As a free spawner, the species scatters eggs without guarding them (Seriously Fish). Very dim lighting and warmer water toward the top of the range are the conditions Seriously Fish associates with spawning.

Egg & Fry Care

Seriously Fish notes the adults can be removed after 2-3 days, with the first fry visible around three days later. Initial food is Paramecium or a proprietary dry food of 5-50 micron grade, progressing to Artemia nauplii and microworm.

Common Challenges

The eggs are light-sensitive, so Seriously Fish advises a very dimly lit spawning tank; the unguarded eggs also need a base or fine plants to fall into, and the small fry require correspondingly small first foods.