Chocolate Gourami Breeding Guide

Breeding Sphaerichthys osphromenoides, a rare maternal mouthbrooder: sexing, upright spawning, the female's brooding, and blackwater needs.

Overview

Sphaerichthys osphromenoides is a labyrinth fish that is challenging to breed and is one of the very few anabantoids in which the female broods the eggs in her mouth; this species and its close relative S. selatanensis are the only anabantoids with maternal (rather than the usual paternal) mouthbrooding. It is restricted to soft, acidic peat habitats and is sensitive to water-quality changes, making it an advanced breeding subject. Adults reach about 6 cm.

Sexing

Males show a uniformly straight lower-jaw profile and a more pointed (acuminate) head shape; females have a slightly rounded lower jaw due to distensible skin that expands during brooding. Depending on population, males may have longer, more pointed unpaired fins and more intense colour, though this is variable.

Breeding Setup

The species can spawn in groups or in pairs. It requires very soft, acidic blackwater: wild fish need pH 4.0-6.5 and hardness from 0 up to about 54 ppm, while captive-bred stock is more adaptable. The recommended temperature is 26-31 C, with peat filtration or botanicals supplying tannins.

Spawning Behavior & Trigger

During courtship a displaying individual takes on a darker, almost greyish pattern while a receptive female intensifies to a deep chocolate brown with the pale bars appearing golden. Unlike most anabantoids, the pair remains almost upright during spawning. The process may take several hours, with eggs laid and fertilised on the substrate and the female then collecting them directly into her mouth.

Egg & Fry Care

The female retains the eggs and developing fry for 7-20 days before releasing 10-40 fully formed, free-swimming juveniles. The fry require live foods such as microworm or Artemia nauplii immediately, together with daily water changes of around 10% of the tank volume.

Common Challenges

The extreme sensitivity to water quality and the need for stable soft, acidic blackwater make this one of the harder anabantoids to breed; brooding females must be left undisturbed throughout the long incubation.