Harrison's pencilfish
Nannostomus harrisoni
Also known as Harrison's pencil fish, Poecilobrycon harrisoni
FreshwaterFish
Care at a glance
- Temperature
- 73–82°F
- 23–28°C
- pH
- 5.5–7.0
- Adult size
- 2.2 in
- 5.5 cm
- Minimum tank
- 16 gal
- 60 L
- Temperament
- Peaceful
- Social behavior
- Shoaling
- Swim level
- Middle
- Difficulty
- Medium
- Breeding
- Hard
- Rarity
- Rare
- Family
- Lebiasinidae
- Origin
- Native to coastal river drainages of Guyana and nearby northeastern South America.
Overview
Keep a shoal of at least 8, which brings out their confidence and gentle sparring displays. They have small mouths and are slow, deliberate feeders, so avoid fast or pushy tankmates that will beat them to food. Soft, tannin stained water and a well planted tank suit them best.
In the wild
Comes from soft, acidic forest streams and blackwater creeks in the Guianas. These are shaded, slow waters full of leaf litter, roots, and overhanging plants. The fish shoal in the middle and upper water among the tangle.
Good to know
Nannostomus harrisoni is one of the larger pencilfishes at around 6 cm, with a slender body and a dark stripe running from snout to tail. Like other pencilfish it switches to a different, blotchy pattern at night. It was once placed in the genus Poecilobrycon.
Did you know
Like all pencilfish, this species swaps its bold daytime stripe for a broken nighttime pattern, so the fish you see at lights out looks like a different animal.
Weekly picks
Tank mates
Harrison's pencilfish is a peaceful, shoaling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.
Sunset dwarf cichlid
Apistogramma atahualpa
Freshwater2.2 in (5.5 cm) · 16 gal (60 L)75–82°F (24–28°C)
Spotted splash tetra
Copella nattereri
Freshwater2 in (5 cm) · 16 gal (60 L)75–82°F (24–28°C)
Gold rabbit snail
Tylomelania gemmifera
Freshwater2.8 in (7 cm) · 16 gal (60 L)75–82°F (24–28°C)
Cardinal tetra
Paracheirodon axelrodi
Freshwater1.8 in (4.5 cm) · 16 gal (60 L)73–84°F (23–29°C)
Guapore cory
Gastrodermus guapore
Freshwater2 in (5 cm) · 16 gal (60 L)72–82°F (22–28°C)
New Guinea blue-eye
Pseudomugil novaeguineae
Freshwater1.8 in (4.5 cm) · 15 gal (55 L)79–86°F (26–30°C)
Common questions
What size tank does a Harrison's pencilfish need?
A Harrison's pencilfish needs at least 16 gal (60 L). It spends most of its time in the middle.
What temperature and pH does a Harrison's pencilfish need?
A Harrison's pencilfish is comfortable at 73–82°F (23–28°C) with a pH of 5.5–7.0.
How big does a Harrison's pencilfish get?
An adult Harrison's pencilfish reaches about 2.2 in (5.5 cm).
Does a Harrison's pencilfish need a group?
Yes. A Harrison's pencilfish is a shoaling species and should be kept in a group, not singly.
Related species
2.4 in (6 cm)18 gal (70 L)70–81°F (21–27°C)Golden pencilfish
Nannostomus beckfordi
2.4 in (6 cm) · 18 gal (70 L)
2 in (5 cm)14 gal (54 L)73–81°F (23–27°C)Marilyn's pencilfish
Nannostomus marilynae
2 in (5 cm) · 14 gal (54 L)
1.6 in (4 cm)14 gal (54 L)75–82°F (24–28°C)Elegant pencilfish
Nannostomus limatus
1.6 in (4 cm) · 14 gal (54 L)
1.6 in (4 cm)17 gal (65 L)73–82°F (23–28°C)One-lined pencilfish
Nannostomus unifasciatus
1.6 in (4 cm) · 17 gal (65 L)
1.6 in (4 cm)14 gal (54 L)75–82°F (24–28°C)Shining pencilfish
Nannostomus nitidus
1.6 in (4 cm) · 14 gal (54 L)
1.4 in (3.5 cm)15 gal (55 L)72–82°F (22–28°C)Hockeystick pencilfish
Nannostomus eques
1.4 in (3.5 cm) · 15 gal (55 L)