Keeping Your Pencilfish: Tank-Bred Red Beckford's Pencilfish

Species Snapshot

  •     Species Name: Nannostomus beckfordi
  •     Common Names: Beckford’s Pencilfish, Coral Red Pencilfish
  •     Size: 1.2 - 1.4 inches (3 - 3.5 cm)
  •     Lifespan: ~5 years
  •     Native Distribution: South America: native in the rivers of Guyana south to the Amazon basin and up the Amazon River to the Negro River

Pencilfish (nannostomus) as a genus are famous for their unique swimming positions, some swim at a 45-degree angle, and others hover around like hummingbirds in their tanks. It is this behavior that draws the attention of fishkeepers, along with their outgoing and active personalities. The Red Beckford pencilfish, with its streamlined body and graceful, gliding schooling patterns is an attractive addition to any aquarium set-up.

Anatomy and Appearance

These slim, torpedo-shaped beauties have a single, thick black lateral stripe that extends from the tail to the face. They are also characterized by their red anal fins and red splotches on their caudal fins. Differentiating the two genders comes down to the coloration. Males are generally a darker shade of brown on the top, with a thicker lateral black stripe. The red anal fins are also typically larger (and longer) than that of their female counterparts. Females are rounder as a whole and have smaller, more rounded anal fins.

Ideal Tank Setup

Temperature: 64° - 82° F (18° - 27.7° C)

pH: 5.0 - 8.0

KH:  4 - 8 dKH

Ideal tank size: 10 gallons and larger

While the Beckford pencilfish can certainly live in a 10-gallon aquarium, they will thrive and look their best in a larger, taller tank as they like to “hover” between the upper and middle levels of the water column. The natural habitats of pencilfish include lots of plants, rockwork, and driftwood with shaded areas. Adding some floating plants can help provide shade from bright aquarium lighting. Slower water flow is preferable, as such avoid using powerful filtration and opt for sponge filters or a gentle hang-on-back filter. 

They do enjoy the water on the slightly more acidic side, adding some Indian almond leaves can help achieve this gently and naturally. That being said, they are relatively hardy fish (particularly the Beckfords), and as such can be kept in a community aquarium setting. As a schooling fish, providing some open areas for them to cruise around in is always much appreciated. Being great jumpers when startled, ensuring that there is a tight-fitting lid will help prevent any potential disasters from occurring!

Keeping your pencilfish.

Diet and Feeding

As with most tropical fish, the Beckford pencilfish will enjoy a varied diet consisting of live, frozen, and dried prepared foods. Given their small mouths, prepared foods such as granules or flakes should be crushed up into smaller sizes to help facilitate feeding. 

Of course, if one wishes to breed these fish, feeding bloodworms, tubifex worms, etc. will encourage breeding behaviors more so than a diet primarily consisting of dried foods. One important note is that they are rather aggressive feeders, so be sure to allow opportunities for the other tank inhabitants to eat their fill!

Temperament and Tank Mates

Being a very peaceful fish, the Beckford pencilfish can be kept with essentially any fish that won’t look at them as a tasty snack! That being said, as mentioned above they can be voracious eaters, so slower swimmers/feeders should be avoided when considering tankmates. 

Their tiny mouths are still capable of eating a shrimplet or two if hungry, so be sure to provide plenty of hiding places for any small invertebrates. These fish are great dither fish and can help coax out the shyer members of the aquarium community as they swim between the upper and middle levels of the tank.


Live foods go a long way when encouraging breeding habits in fish, and the Beckford pencilfish is no exception. Recreating their natural environment ensures the best chances for spawning to occur, and this primarily consists of dimmer lighting and slightly more acidic water levels. A darker substrate has been reported to result in more successful spawns. 

Having plants that provide leafy coverage will be hiding eggs and fry, as the parents exhibit no parental care whatsoever. More surface area also means more chances for developing microfauna and biofilm for fry to feed on in their initial few days of life. Of course, powdered foods can be introduced over time as the babies grow larger in size. 

If you want to start building your perfect aquarium and need help, contact us today!

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