Two Stripe Pencilfish (Nannostomus digrammus) are native to the Branco, Madeira, Trombetas, and Tapajós river drainage in the central Amazon basin in Brazil, and the Rupununi basin in Guyana. In recent years, similar specimens with an additional thin dark stripe on the lower part of the body were exported from Columbia to Peru which were also believed to be Nannostomus digrammus.
Like most pencilfish species, the Two Stripe Pencilfish typically frequents small rivers, sluggish tributaries, slow moving streams, and swampy areas that have an abundance of aquatic vegetation, submerged bogwood, and usually lots of leaf litter.
The Two Stripe Pencilfish is a small, elongated species that has two prominent dark (usually maroon colored) horizontal stripes along the body. One along the lateral line from the base of the tail through the lower portion of the eye, and the other above along the upper portion of the body.
Nannostomus digrammus is very similar to and often confused with Nannostomus bifasciatus, however, Nannostomus digrammus has an adipose fin which Nannonostomus bifasciatus lacks.
Adult males are always more intensely colored, smaller than females, and have an extended anal fin which is used in courtship.
The Two Stripe Pencilfish is a shoaling species that is best kept with at least 8 to 10 of their own kind in a species tank or in a community tank with like sized loricariid catfishes, peaceful characids, dwarf cichlids, and the smaller callichthyids.
They do well in a densely planted tank of at least 15 gallon capacity with a dark sand or fine gravel substrate, some floating plants to diffuse overhead lighting, some driftwood or bogwood for the fish to hide, and some dried Indian Almond Leaves or other leaf litter that promotes the growth of microbe colonies during their decomposition. The dried Indian Almond leaves produce tannins and other beneficial chemicals, and establish a secondary food source as the leaves slowly decay.
Because Nannostomus digrammus prefer slow moving water in their aquarium, an air powered corner sponge filter is all the filtration that is needed.
As of this date, the Two Stripe Pencilfish has not reportedly been bred in an aquarium environment.
In their natural environment, the Two Stripe Pencilfish is a micro predator that feeds on zooplankton, small worms, and tiny invertebrates. In an aquarium environment, it will eat dried foods but they should also be provided with daily meals of small live, frozen, or freeze dried Moina, bloodworms, Daphnia, grindal worms, tubifex, brine shrimp, etc.
Although the Two Stripe Pencilfish is uncommon, it is usually available to tropical fish keeping enthusiasts through specialty fish keeping shops or online at reasonable prices when they are 3/4″ to 1″ in length.
Minimum Tank Size: 15 gallons
Care Level: Moderate
Hardiness: Moderately Hardy
Water Conditions: 72-82° F, 18 – 178 ppm, pH 5.0-7.0
Max. Size: 1.25″
Color Form: Silver, Black
Compatibility: Single species tank
Origin: Brazil, Guyana
Lifespan: 5 years
Aquarist Experience Level: Beginner