Tiny Killifish

Aphyosemion exiguum is one of the smallest members of the Aphyosemion genus, native to shaded forest streams in Cameroon. Despite its modest size, males display attractive greenish body colouration with scattered red spots and some fin colouration, making them genuinely appealing for the nano and species tank keeper. Females are typically plain brown but are necessary for breeding.

Given its small size, a 30 L species tank is sufficient and preferred — this allows better monitoring of the fish and more controlled water parameters. Very soft, slightly acidic water is essential. Eggs are deposited on fine-leaved plants or a yarn mop and hatch after two to three weeks of incubation in damp peat. Fry are small and require micro-foods such as infusoria or vinegar eels as first food.

A. exiguum is a charming species for keepers interested in nano fish and biotope aquaria. Its small size, modest food requirements, and peaceful temperament make it an ideal subject for a dedicated West African forest stream nano tank.

Water: 20–24 °C, pH 5.5–7.0, very soft water (GH 1–6) essential. Tank: 30 L species tank; fine-leaved plants and leaf litter for comfort and spawning. Feeding: Very small live foods — micro worms, infusoria, Artemia nauplii, Daphnia; feed daily. Breeding: Tiny eggs deposited on mop; hatch after 2–3 weeks; fry need micro-foods. Compatibility: Species tank only; too small for most community tanks.