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
Harrison's pencilfish is a peaceful shoaling fish that suits a soft-water, well planted tank. It is a step up from the easiest fish, best kept by someone with a little experience.
Did you know
Harrison's pencilfish, like all pencilfish, swaps its bold daytime stripe for a broken pattern at night. The fish you see at lights out looks like a different animal.
Caring for the Harrison's pencilfish
Keep Harrison's pencilfish in a shoal of at least eight, in a well planted tank of 16 gal (60 L) or more. A shoal brings out their confidence and their gentle sparring displays.
Give them soft, tannin-stained water at 73 to 82°F (23 to 28°C) and a pH of 5.5 to 7.0. They have small mouths and are slow, deliberate feeders.
Harrison's pencilfish are peaceful and safe with other community fish. Avoid fast or pushy tank mates, which will beat them to food. Breeding them is hard.
Good to know
Harrison's pencilfish is one of the larger pencilfishes, with a slender body and a dark stripe running from snout to tail. It belongs to the family Lebiasinidae and was once placed in the genus Poecilobrycon.
In the wild
Harrison's pencilfish 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.
Weekly picks
Tank mates
The 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.
Neocaridina shrimp
Neocaridina davidi
Freshwater1.6 in (4 cm) · 5 gal (19 L)59–84°F (15–29°C)
Guppy
Poecilia reticulata
FreshwaterBrackish2.4 in (6 cm) · 10 gal (38 L)64–82°F (18–28°C)
Neon tetra
Paracheirodon innesi
Freshwater1.5 in (3.8 cm) · 11 gal (40 L)70–77°F (21–25°C)
Golden dwarf cichlid
Nannacara anomala
Freshwater3.1 in (8 cm) · 16 gal (60 L)72–82°F (22–28°C)
Fanning characin
Pyrrhulina rachoviana
Freshwater2 in (5 cm) · 16 gal (60 L)68–79°F (20–26°C)
Gold rabbit snail
Tylomelania gemmifera
Freshwater2.8 in (7 cm) · 16 gal (60 L)75–82°F (24–28°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)