Harrison's Pencilfish Breeding Guide

Nannostomus harrisoni has been bred in aquaria, albeit rarely. Use densely planted containers with fine spawning mops; fry appear a day or two after spawning.

Overview

Nannostomus harrisoni is a slim pencilfish endemic to the Demerara River basin in eastern Guyana, including tributaries such as the Haiama and Kuruabaru rivers. Seriously Fish records a size of 40-45 mm SL. It is a peaceful, gregarious, top-dwelling species best suited to soft acidic water.

Sexing

Males display red pigmentation in the pelvic, anal and caudal fins, whereas females have hyaline (clear) pelvic and anal fins with paler caudal colouration. Males are slimmer than females, especially gravid females (Seriously Fish).

Conditioning

As a micropredator it should receive daily meals of small live and frozen fare such as Artemia nauplii, Moina and grindal worm. Soft, acidic water suits it: Seriously Fish gives 22-28 C, pH 5.0-7.0 and hardness 18-179 ppm. Keep groups of ten or more, as males rarely engage in aggression.

Breeding Setup

Seriously Fish notes that controlled breeding requires densely planted containers with fine wool mops or plants, which provide both spawning sites and refuge for the scattered eggs in the absence of parental care.

Egg & Fry Care

Reproduction has been achieved in aquaria, albeit rarely. Adults spawn after 2-3 days together and can then be removed; fry appear a day or two later (Seriously Fish). As with other Nannostomus, the smallest live and prepared foods are required for the first-feeding fry.