Three Lined Pencilfish

Nannostomus trifasciatus

Three Lined Pencilfish is a peaceful middle-to-top swimmer. Keep in a school of 8+.

PeacefulMiddle to top swimmerKeep in a school of 8+Beginner – Intermediate

Save this fish or add it directly to one of your aquariums.

Quick facts

Adult size
≤ 1.6" (≤ 4 cm)
Aquarium size
16 US gal (60 L) or larger / ≥ 29.5" (≥ 75 cm) minimum length
Care level
Beginner – Intermediate
Temperament
Peaceful
Swimming zone
Middle to top swimmer
Temperature
73–81°F (23–27°C)
pH
5.5–7
GH
2–8 dGH
Diet
Omnivore
Lifespan
up to 5 years
Group behavior
Keep in a school of 8+

Care requirements

Care level: Beginner – Intermediate.

Lifespan: up to 5 years.

Aquarium size and space needs

Minimum aquarium size: 16 US gal (60 L) or larger / ≥ 29.5" (≥ 75 cm) minimum length. Plan the layout and stocking within that limit.

Water parameters

Suitable water: temperature 23–27 °C, pH 5.5–7, GH 2–8 dGH.

Temperament and compatibility

Three Lined Pencilfish is peaceful and suits calm community fish.

Keep in a school of 8+.

Swimming zone and behavior

This fish uses the middle to upper part of the aquarium, so leave enough open swimming space for movement and feeding. Keep in a school of 8+.

Feeding

As an omnivore, Three Lined Pencilfish should receive a varied diet rather than one repeated food type.

Before adding this fish

  • Plan for an aquarium of 16 US gal (60 L) or larger / ≥ 29.5" (≥ 75 cm) minimum length.
  • Make room for its social group.
  • Avoid aggressive or highly competitive fish.
  • Keep in a school of 8+.
  • Offer a varied diet that matches this species.

Natural habitat and origin

Origin: Brazil, Peru, Colombia, Guyana, Bolivia.

Similar fish profiles

Use these profiles to compare fish with similar care level, size, temperature range, or swimming behavior.

Barred Pencilfish Nannostomus espei Same genus Same family Similar care level Beginner – Intermediate ≤ 1.2" (≤ 3 cm) 70–81°F (21–27°C) Black Neon Tetra Hyphessobrycon herbertaxelrodi Similar care level Same temperament Same swimming zone Beginner – Intermediate ≤ 1.6" (≤ 4 cm) 68–79°F (20–26°C) Blue Purple Emperor Tetra Inpaichthys kerri Similar care level Same temperament Same swimming zone Beginner ≤ 1.6" (≤ 4 cm) 72–79°F (22–26°C) Adonis Tetra Lepidarchus adonis Similar care level Same temperament Same swimming zone Intermediate ≤ 0.8" (≤ 2 cm) 70–79°F (21–26°C) African Copper Ribbon Tetra Rhabdalestes septentrionalis Similar care level Same temperament Same swimming zone Beginner – Intermediate ≤ 2.8" (≤ 7 cm) 72–82°F (22–28°C) African Red Eyed Tetra Arnoldichthys spilopterus Similar care level Same temperament Same swimming zone Beginner – Intermediate ≤ 3.1" (≤ 8 cm) 72–81°F (22–27°C)

FAQ

How large does Three Lined Pencilfish get?

Three Lined Pencilfish reaches ≤ 1.6" (≤ 4 cm).

What aquarium size does Three Lined Pencilfish need?

Use an aquarium of at least 16 US gal (60 L) or larger / ≥ 29.5" (≥ 75 cm) minimum length.

Is Three Lined Pencilfish peaceful?

Yes. Three Lined Pencilfish is recorded as peaceful and is best planned with calm community fish that do not harass it or dominate the feeding area.

What temperature is suitable for Three Lined Pencilfish?

Keep it between 23 to 27 °C.

Should Three Lined Pencilfish be kept alone or in a group?

Three Lined Pencilfish: Keep in a school of 8+.

Scroll to Top