Purple pencilfish

The purple pencilfish is a small, slender characoid from soft, blackwater tributaries of the upper Amazon in Peru. Males show intense purple-red flanks and a bright red caudal base, colours that peak in mature schools kept over dark substrate among fine-leaved plants and leaf litter. It is a peaceful, shoaling species best kept in groups of eight or more, ideally in a well-planted, dimly lit tank with tannin-stained water and gentle flow. Water should be warm, soft and acidic, with low carbonate hardness. Feed small live and frozen foods such as microworms, Artemia nauplii, cyclops and finely crushed flake; the small upturned mouth prefers tiny items. Good tankmates include other small tetras, dwarf cichlids and pencilfish. Stable, clean water and subdued lighting bring out the best colour and behaviour.