Three Lined Pencilfish
The three lined pencil fish, or trilineatus pencil, has three horizontal lines on a copper and red body. These are small schooling fish from small rivers of the Amazon and only grow to an inch. Very gentle fish, they are also hardy and will eat flake food. However, these are wild Amazon fish and will not tolerate pH higher than about 7.6.
Quick Facts
| Scientific Name | Nannostomus trifasciatus |
|---|---|
| Origin | Amazon basin, South America |
| Care Level | Moderate |
| Temperament | Peaceful |
| Adult Size | Up to 2″ |
| Lifespan | 3–5 years |
FAQ
What is the ideal pH level for three lined pencilfish?
The three lined pencilfish will not tolerate pH higher than about 7.6.
Are these fish suitable for beginners?
Yes, they are gentle and hardy, making them a good choice for beginners with a moderate care level.
What type of food do they eat?
They will eat flake food and are known to be easy to feed.

Ella Wright –
I bought these fish for my community tank and they’ve been very active and peaceful. They school well and don’t stress other fish. I feed them flake food daily and they seem to enjoy it. The pH in my tank is 7.4, which is within their tolerance range.
Elizabeth Glover –
The fish arrived quickly and look healthy. They are small but vibrant with the copper and red coloring. I keep them in a 10-gallon tank with other peaceful species. They don’t fight or chase others, which is great for a shared environment.
Cameron Morrison –
Easy to care for and very active. I’ve had them for three months now and they still look bright and healthy. I maintain a stable pH and temperature, and they thrive in a well-planted tank.