Harrisoni Pencilfish

Nannostomus harrisoni is an understated pencilfish from the rivers of Guyana, displaying a pale golden-cream body traversed by a diffuse dark stripe and a subtle red flush to the fins in well-conditioned males. It is closely related to N. beckfordi but is generally considered to be a slightly more demanding species, benefiting from softer, more acidic water conditions.

In a well-established planted aquarium with soft, slightly acidic water, this species settles quickly and forms attractive schools. It is tolerant of gentle community tankmates but should not be housed with boisterous or nippy fish. Floating plant cover and some shaded areas are appreciated.

Diet is straightforward: quality micro-pellets, crushed flake, and regular live or frozen offerings of baby brine shrimp and daphnia maintain it in excellent health. Keeping groups of eight or more ensures relaxed behaviour and regular social display.

Water: 23–27°C, pH 5.0–7.0, soft (GH 1–10, KH 0–5); blackwater conditions recommended. Tank: 60 L minimum; planted with gentle flow, floating cover, and dark substrate. Feeding: Micro-pellets, crushed flake, baby brine shrimp, daphnia, micro-worms. Breeding: Egg-scatterer; condition on live foods; uses fine-leaved plants for spawning. Compatibility: Peaceful; suitable with small tetras, nano rasboras, corydoras, and dwarf shrimp.