Nannostomus unifasciatus

Alternative names

 * One-Lined Pencilfish,

Sexing

 * The anal fin of the male has red colouration, while a female's anal fin will only be white and black. Mature females are also plumper than males. These fish are tricky to breed in captivity.

Tank compatibility

 * A peaceful fish that must be kept in a shoal of at least 5 of its own kind. Keep with other non-predatory peaceful fish of similar size.

Diet

 * Should accept most foods including live/frozen foods such as brine shrimp and daphnia as well as small pellet and flake food.

Feeding regime

 * Feed once or twice a day.

Environment Specifics

 * These fish require a mature spacious tank without very bright lighting. They appreciate a planted tank with floating plants to diffuse the light, combine dense planting with some open swimming space. They prefer a dark substrate to a light one. These fish can be very sensitive to water chemistry, preferring acidic water.

Behaviour

 * This is a peaceful active little fish that are known to swim at an angle. When they are stressed by water conditions their colours will fade.

Identification

 * A slender elongated fish which has an olive green-brown back. A fine, iridescent gold-coloured line extends from the tip of the snout, through the eye and to the caudal fin. Right below this line is a broad, black band that also extends from the snout, through the eye, and continues to the tip of the lower lobe of the caudal fin. The belly is pale cream-white. A small, black, oval spot is located on the upper lobe of the caudal fin. The anal fin is black with a white edging, while the other fins are transparent.