• Species: Nannostomus anduzei

  • Species: Nannostomus beckfordi

  • Species: Nannostomus beckfordi

  • Species: Nannostomus eques

  • Species: Nannostomus harrisoni

  • Species: Nannostomus marginatus

  • Species: Nannostomus marginatus

  • Species: Nannostomus nitidus

  • Species: Nannostomus unifasciatus

  • Species: Nannostomus espei


06 January 2017

Taxonomy and Distribution

Pencilfish belong to the genus Nannostomus of the Lebiasinidae family of Characins. The 17 species (15 of which are available in the aquarium industry) of Nannostomus are widespread throughout South America. Species can be found in Colombia, Venezuela, Peru, the southern Amazon Basin and Brazil to name a few. Most species found in the aquarium industry are wild caught with just Nannostomus harrisoni and Nannostomus beckfordi being commercially produced for the hobby.

General Care

Nannostomus thrive in soft, acidic waters. Provide a pH between 5.5 and 6.8 and a temperature between 25 and 28C. The tank should be well planted with dim lighting. The substrate should preferably be dark but can otherwise be course or fine. Filtration should be efficient, as these fish will do best in water with low nitrate levels. Nannostomus species are generally peaceful and will do well with a variety of other peaceful fish of a similar size such as other Nannostomus, Rasbora, Tetra and Corydoras. They should be kept in groups no smaller than six. These fish prove to be an ideal choice as dither fish for some of more nervous species such as Apistogramma spp. Bare in mind, however, that they will also be considered food by larger fish such as predatory catfishes as they remain relatively small. Nannostomus spp. will survive on a diet of dried flake food, but in order to see them at their best and to encourage spawning, they must be fed a varied diet. Provide flakes along with frozen and live foods such as bloodworm and tubifex. They can also be fed soft-bodied insects such as crickets. Nannostomus spp. are enthusiastic eaters and may outcompete more timid tankmates.

Nannostomus marginatus Dwarf Pencilfish

The Dwarf Pencilfish, Nannostomus marginatus is one of the smallest members of the Nannostomus genus reaching just 35mm when fully grown. It is widespread throughout South America; being recorded in Brazil, Guyana, Colombia and Peru. The body has dark horizontal lines and all the fins save the caudal and pectoral fins are bright red in colouration. This species is somewhat shy and will only thrive in optimum conditions.

Nannostomus beckfordi Golden Pencilfish

The Golden Pencilfish, Nannostomus beckfordi is endemic to the swamps and slow-moving waters of Brazil, French Guiana, Guyana and Suriname. At 6cm it is an attractive species with a golden-red body marked with a single horizontal stripe. It is one of the only two species to be commercially produced for the aquarium industry.

Nannostomus harrisoni Harrison’s Pencilfish

Nannostomus harrisoni is one of the largest species of Pencilfish, with an adult length of approximately 6.5cm and can be found throughout the Guyanas in South America. It has an elongated body with a single dark horizontal stripe running from nose tail with a dorsal and caudal fin edged in red. It is one of the only two species of Pencilfish bred on a commercial scale for the aquarium industry.

Nannostomus mortenthaleri Coral Red Pencilfish

The Coral Red Pencilfish Nannostomus mortenthaleri is a relatively recent discovery having been described by Weitzman and Weitzman in 2002 following its discovery in the Rio Nanay in Peru. One of the more colourful species of Nannostomus at 4cm it sports brilliant red banding from the snout to the caudal peduncle, although females tend to be less brilliantly coloured.

Nannostommus eques Hockeystick Pencilfish

The Hockeystick Pencilfish Nannostomus eques is an attractive species indigenous to Guyana, Colombia, the Rio Negro and Amazon River Basin. It typically reaches an adult length of approximately 5cm and has a body marked with two horizontal stripes; a darker one that runs from the snout along the length of the body before running down the bottom half of the caudal fin along with a lighter stripe edging it. This species can be a timid feeder and may be outcompeted by more active species.

Nannostomus espei Barred Pencilfish

The Barred Pencilfish, Nannostomus espei, is a species endemic to the Mazaruni River system in Guyana capable of reaching an adult length of approximately 3.5cm. It is one the lesser-seen species of Nannostomus in the aquarium industry due to its limited distribution in comparison to other species and its proven difficulty to catch. It has a golden body with a line of diagonal black markings running along its length. Unlike other species of Nannostomus it retains these markings day and night.

Nannostomus anduzei

Nannostumus anduzei is a relatively new species seen in the aquatic hobby, having only been previously available through accidental by-catches. Originating from the waters of Venezuela, it reaches an average length of around 2cm. Its body is a golden-brown whilst the anal and caudal fins are marked with brilliant red.

Nannostomus digrammus Twin-Stripe Pencilfish

The Twin-Stripe Pencilfish Nannostomus digrammus is one of the more regularly seen species in the aquarium industry and is widespread throughout Brazil and Guyana. It reaches approximately 3cm when fully grown, and, as its name suggests, it sports a silvery body marked with two dark horizontal stripes running from the snout to the caudal peduncle.

Nannostomus britskii Spotstripe Pencilfish

The Spotstripe Pencilfish, Nannostomus britskii, originates from the states of Para and Amazonas in Brazil. It is very rarely seen in the aquarium trade. At 3cm in length, it has a light body with a dark horizontal band running from behind the operculum to the caudal peduncle whilst the top of the body is also dark.

Nannostomus unifasciatus One-Striped Pencilfish

The One-Striped Pencilfish Nannostomus unifasciatus can be found in the shallows of streams and small rivers in the Rio Negro, Guyana, The Amazon Basin, Brazil and Colombia. This species typically reaches around 6.5cm in length and has an elongated body brown-black in colour. The body is also marked with a horizontal golden stripe extending from the snout through to the caudal fin, which is edged with a darker stripe.

Nannostomus bifasciatus Two-Lined Pencilfish

The Two-lined Pencilfish is indigenous to the swamps and slow-moving rivers of French Guiana, Brazil and Suriname. It is one of the only two species that adopts an upward-angled swimming position. Reaching an adult length of around 3.5cm it has a grey-black body sporting two white lines. One of these extends from the eye to the caudal peduncle whilst the bottom line extends to the anal fin.

Nannostomus nitidus Shining Pencilfish

The Shining Pencilfish Nannostomus nitidus is indigenous to the Capim Rover Basin in Brazil. It reaches a maximum length of 3.5cm and has a body silverish in colour. The body is marked with two horizontal bands running from the snout to the caudal peduncle; the top stripe an iridescent white and the bottom black in colour.

Nannostomus marylinae Greenstripe Pencilfish

The Greenstripe Pencilfish Nannostomus marylinae originates from the Negro and Vichada river basins in South America. Attaining a maximum length of around 5cm it has a brownish-silver body; it has a singular black band running from the snout to the caudal peduncle. N. marylinae is a relatively recent discovery having only been described in 2003 by Weitzman and Weitzman.

Nannostomus rubrocaudatus Purple Pencilfish

The Purple Pencilfish Nannostous rubrocaudatus is arguably one of the most attractive species of Nannostomus. Originating from the Rio Marano in Peru, its body is bright red in colouration with a silver head. Several black bands run from the snout of the fish along the length of its body. It typically reaches around 3cm in length when fully grown.