Pygmy Spotted Rasbora (Boraras maculatus) Breeding Guide

How to breed the Pygmy Spotted Rasbora (Boraras maculatus): a continuous egg-scatterer with no parental care, laying small egg batches daily into moss in soft, acidic water.

Overview

Boraras maculatus is an egg-scattering, continuous spawner that exhibits zero parental care, laying small egg batches daily when conditions are favourable. In a well-established aquarium fry may appear without intervention, while a small spawning container is used to raise higher numbers.

Sexing

Mature females are noticeably rounder-bodied and often a little larger than males. Males display more vibrant coloration, with dominant individuals showing the most intense hues.

Conditioning

Condition adults well and introduce two to three conditioned pairs per container, transferring them slowly to minimise stress. Spawning typically begins the following morning when the fish are settled.

Breeding Setup

Use a separate 10-15 litre container with very dim lighting and a bare base or mesh that allows eggs to fall through but prevents adult access; plastic grass-type matting works well. Add a decent clump of java moss or other fine-leaved plant filling about half the space, plus an optional small air-powered sponge filter. Spawning water is pH 5.0-6.5, hardness 1-5 °H, and temperature toward the upper range (about 26-28 °C).

Spawning Behavior & Trigger

Small egg batches are laid daily among the moss and plants when conditions are favourable. The pair or pairs should be left in situ for no more than a couple of days before being removed, to limit egg predation.

Egg & Fry Care

Eggs hatch by day two, and the fry then survive on their yolk sacs for about 24 hours. Their first food must be very small, such as Paramecium or other microscopic organisms; after 7-10 days they can take Artemia (brine shrimp) nauplii and microworms. Delay water changes for the first one to two weeks to avoid shocking the young fish.

Common Challenges

Providing first foods small enough for the minute fry and avoiding early water changes are the main hurdles, as with the other Boraras species. A bare base or mesh, plus prompt removal of adults, reduces egg losses.