Vaillant's Chocolate Gourami

Sphaerichthys vaillanti is a rarely seen chocolate gourami from Sarawak and Kalimantan on the island of Borneo. Males of this species are more richly patterned than the common S. osphromenoides, with deeper brown banding and a somewhat greener iridescent sheen on the scales. It is a female mouthbrooder.

Like all Sphaerichthys species, S. vaillanti demands extreme water quality: very soft, acidic blackwater is non-negotiable. The species is notoriously difficult to import in good condition and requires a long quarantine period with careful acclimatisation. A species-only biotope is by far the most successful approach.

Successful maintenance requires a mature, heavily planted, peat-filtered blackwater aquarium with stable parameters. Groups of five or more individuals kept together show reduced stress and more natural behaviour. Breeding has been achieved in captivity but remains a significant accomplishment.

Water: 24–28°C, pH 4.0–6.0, extremely soft (GH 0–3) — use RO or rainwater with peat conditioning. Tank: 60 L species tank; dense vegetation, leaf litter, no strong current, dim lighting. Feeding: small live foods (daphnia, cyclops) and quality micro granules; avoid dry food exclusively. Breeding: female mouthbroods; stable environment and conditioning on live food promotes spawning. Compatibility: species-only setup strongly recommended; extremely sensitive to stress.