Betta miniopinna

Betta miniopinna is one of the rarest and smallest bettas in the hobby, endemic to Bintan Island, Riau Province, Indonesia. Adult males barely exceed 3 cm and display disproportionately vivid red dorsal and caudal fin tips on an otherwise subtle brownish body. The species is classified as Critically Endangered due to severe habitat loss.

In the aquarium, B. miniopinna requires ultra-soft, highly acidic blackwater conditions. The tank should be set up as a blackwater biotope with Indian almond leaves, peat, and driftwood. Water parameters must be stable — even brief exposure to hard or alkaline water causes rapid deterioration. This is strictly a species for experienced blackwater keepers.

Breeding can be achieved in carefully managed nano setups. As a bubblenester, the male builds a modest nest under floating vegetation and guards the eggs. Fry are tiny and require infusoria or commercial first foods before progressing to micro nauplii.

Water: 23–27°C, pH 4.5–6.0, very soft (GH 0–4) — strict blackwater conditions are non-negotiable. Tank: 20 L nano species tank with tannin-rich water, leaf litter, and floating plants; no strong flow. Feeding: micro live foods — vinegar eels, infusoria, small daphnia; very small micro pellets. Breeding: bubblenester; male guards eggs; fry require infusoria for first week. Compatibility: species-only; too small and fragile for any community setting.