Chocolate Gourami Selatanensis

Sphaerichthys selatanensis is a mouthbrooding chocolate gourami endemic to South Kalimantan (southern Borneo), where it inhabits tannin-rich, blackwater peat swamps and slow-moving forest streams. It closely resembles the common chocolate gourami (S. osphromenoides) but tends to display a somewhat more uniform brown patterning with less prominent banding.

Like all chocolate gouramis, S. selatanensis is a demanding species that requires extremely soft, acidic water to remain healthy. Even brief exposure to harder or more alkaline conditions causes rapid stress and susceptibility to disease. Maintaining this species successfully is considered a benchmark achievement in Southeast Asian biotope keeping.

Mouthbrooding behaviour in this species involves the female incubating the eggs. Groups of five or more kept in a mature, well-filtered blackwater aquarium show the most natural behaviour and the best breeding success.

Water: 24–28°C, pH 4.0–6.0, very soft (GH 0–4) — strict blackwater with peat filtration is essential. Tank: 60 L minimum for a group; heavily planted, dim lighting, leaf litter substrate, minimal flow. Feeding: small live and frozen foods — daphnia, micro bloodworm, and high-quality micro granules. Breeding: female mouthbrooder; keep in groups to encourage natural pair formation. Compatibility: species-only or with equally sensitive blackwater fish such as small wild bettas.