Widely-distributed throughout the Amazon, Orinoco, Essequibo, and Tocantins river systems in Brazil, Peru, Bolivia, Ecuador, Colombia, Venezuela, and Guyana.

Type locality is ‘Rio Cupai [= Rio Cupari], Rio Tapajós basin, Amazon River drainage, Pará State, Brazil’.

Inhabits sluggish blackwater tributaries, small rivers and swampy areas, particularly in areas with dense growth of aquatic or overhanging riparian vegetation, submerged woody structures and leaf litter. The water is typically stained darkly with humic acids and other chemicals released by decaying organic material, the dissolved mineral content is generally negligible and pH can be as low as 4.0.

N. minimus occurs sympat…

This species is sometimes traded as ‘Espei’s’, ‘four-barred’ or ‘banded’ pencilfish and is sought after in the aquarium hobby, though normally quite expensive to buy.

It’s most-easily identified by its unique colour pattern of 5 dark, vertically-orientated bar-like markings on each flank, this in direct contrast to the horizontal stripes seen in other congeners…