Anduzei Pencilfish

Nannostomus anduzei, the Anduzei Pencilfish, is one of the smallest and most demanding pencilfish species in the hobby, barely exceeding 2cm in total length. Found in the highly acidic blackwater streams of Venezuela and the upper Amazon region, it requires extremely specific water chemistry — pH values below 5.5, near-zero hardness, and soft, tannin-stained water that mimics its natural peat swamp habitat. The classic pencilfish striped pattern is present in miniature: a bold black lateral band bordered by a narrow gold stripe that gives the fish its characteristic appearance. Despite its tiny size, this species benefits from being kept in larger groups — the security of numbers reduces stress-induced hiding behaviour. This is a species strictly for advanced aquarists who can provide and maintain the required blackwater chemistry and appropriate micro-prey feeding.

Maintain in a dedicated blackwater nano aquarium with pH 4.0–5.5, near-zero GH and KH, and dark, tannin-stained water from Indian almond leaves or peat filtration. Feed micro-sized foods: paramecia, vinegar eels, micro worms, and the finest commercial foods. Keep in groups of 10+. Avoid all hard-water fish. Extremely sensitive to water quality changes — perform careful, small water changes only.