Three-lined pencilfish

Geographic Origin and Biotope: Immense Amazonian range: from Peru, to Colombia, Brazil and Guyana (Rio Negro, Rio Ucayali). Lives in "Igapó", turbid but slow flood lakes.

Taxonomy and Morphology: Three-Lined Pencilfish (Nannostomus trifasciatus). Among the largest pencilfish (5-6 cm / 2-2.4 inches). Cylindrical torpedo profile. The "three-band" livery is the trait from which it takes its scientific name.

Social Behavior: Show-off. Males spend the day facing off shoulder to shoulder, vibrating vigorously to establish the school's hierarchy. Despite being combative, the brawls do not lead to injuries or deaths.

Coloration and Sexual Dimorphism: Three decisive horizontal black bands interspersed with vibrant gold stripes. The unique trait (which distinguishes it from the marginatus) are the incredible intense Blood Red spots splashed transversely between the gold and black bands. Males have a thicker red base on the dorsal, caudal, and anal. At night the three lines disappear in favor of 3 large oblique gray "stamps".

Aquarium Setup: Long tank (at least 80-100 cm / 32-40 inches for male duels). Needs ample horizontal space in mid-water combined with dense peripheral plant bushes. The shadows generated by tall stem plants (Cabomba) will calm them down.

Diet and Feeding: Lively micropredators. Will greedily eat small insects fallen in the water, daphnia, brine shrimp and will gladly accept flakes and excellent quality micro-granules scattered on the surface.

Water Quality: Very robust for a Nannostomus. Although they like acidic pH and amber water (ideal for red colors), they will thrive and live 5+ years even in normal soft conditioned tap water (Ph 7.0, GH 8).

Compatibility and Tankmates: The emblem of the South American Community Aquarium. Robust and immovable, they coexist well with Dwarf Cichlids (Ramirezi, Apistogramma), Angelfish (provided the tetras are adults), Tetras (Cardinals, Rummy-nose) and Loricariids.

Aquarium Reproduction: Males chase females up to the floating vegetation, scattering tiny sticky eggs. The brood will be relentlessly consumed by themselves if not placed in a sterile tank with an egg-saver net on the bottom.

Risks and Diseases: Misunderstood nocturnal fading. A fright or the nocturnal phase triggers camouflage (Fright pattern): the fish becomes pale white, the lines disappear and spots appear. The aquarist often believes it is dying or sick, but they recolor as soon as there is light.