Nannostomus unifasciatus is an interesting pencilfish from the Rio Negro in northern South America. They are sometimes known as Hockey-Stick pencils (a name shared with N. eques) for their dark stripe that abruptly hooks into the tail, form a hockey-stick shaped marking. Like N. eques, these fish spend almost all their time swimming at an approximately 45 degree angle, giving them a unique look compared to most other schooling fish. Like most pencilfish, One-Lined pencils make excellent dither fish for dwarf cichlids, such as Apistogramma spp.
These are adults, around 1.5-2" long.