Strawberry Rasbora (Boraras naevus) Breeding Guide

Boraras naevus is an egg-scattering continuous spawner with no parental care, breedable in dimly lit nano tanks with fine-leaved cover and soft acidic water.

Overview

Boraras naevus, the strawberry rasbora, is a tiny Southeast Asian cyprinid reaching only about 15-20 mm. According to Seriously Fish it is an egg-scattering, continuous spawner that exhibits zero parental care, laying relatively small numbers of eggs daily when conditions are favourable.

Sexing

Seriously Fish reports that females are noticeably rounder-bellied, often a little larger, and less intensely coloured than males. Males display a distinctively larger anterior dark blotch on each flank, a feature unique to this species within the genus.

Conditioning

The species does best on live and frozen foods such as Daphnia and Artemia alongside quality flakes, and should not be fed dried foods exclusively. Well-conditioned adults spawn readily.

Breeding Setup

Seriously Fish recommends dimly lit containers of about 10-15 litres with a bare base or a mesh that lets eggs fall through while excluding adults; plastic grass matting works well. Java moss or fine-leaved plants should fill around half the space, and a small air-powered sponge filter is optional. Suggested values are pH 5.0-6.5, hardness 1-5 dH and the upper temperature range.

Spawning Behavior & Trigger

As a continuous spawner the species scatters small numbers of eggs daily among fine vegetation under favourable conditions. Seriously Fish notes that while it will eat its eggs, it appears not to actively hunt for them, so dense cover helps protect the clutch.

Egg & Fry Care

Eggs hatch by the second day after spawning. The fry live on their yolk sacs for around 24 hours, then need microscopic foods such as Paramecium; after 7-10 days they accept Artemia nauplii and microworm.

Common Challenges

The very small size of fish and fry means tiny first foods and stable, soft, acidic water are essential. Because adults may eat eggs, abundant fine-leaved cover or a mesh base improves survival.