Harrison's Pencilfish

About

Harrison's pencilfish (Nannostomus harrisoni) is a slender, small characid from the Demerara River basin in Guyana, and it doesn't turn up in the hobby often. When it does appear, it's frequently mixed in as incidental bycatch alongside shipments of the more common tube-mouth pencilfish. Like other Nannostomus, it carries two lateral stripes along its body and switches to a cryptic, vertically-barred night pattern after dark. A color shift that happens automatically, even in fish without functional vision, so don't be alarmed if your lights-on morning reveal very different-looking fish than you had the evening before. Harrison's pencilfish is genuinely peaceful, though its small adult size and shy temperament mean a standard bustling community tank isn't the best fit. It works far better alongside similarly scaled, calm characids or smaller catfish, and it makes a surprisingly useful dither fish for Apistogramma and other dwarf cichlids, patrolling the mid-to-upper water column without bothering fry. This is a gregarious species. A group of ten or more will show noticeably bolder, more natural behavior than a handful will, and males rarely do each other any real harm. Breeding in captivity is possible but uncommon, and the fry are tiny, so successfully raising them takes some deliberate preparation and the right first foods.