Overview
The serpae tetra is a small but fiery fish with a deep blood-red body, a splash of black on its shoulder, and dark, flag-like fins. It comes from the slow-moving streams and floodplains of the Amazon basin in South America, including parts of Brazil and Paraguay. Its rich red color makes it a real eye-catcher in a planted tank, especially when the light hits a whole group at once.
Serpae tetras have a bit of a naughty side. They are known as fin nippers, meaning they sometimes chase and nibble the fins of slower tankmates or of each other. The trick is to keep them in a good-sized group of at least six, which spreads out their busy energy so they pick on each other in play rather than bullying other fish. Kept this way, they are hardy, colorful, and full of personality.
| Care level | Easy |
| Adult size | 1.75 in (4.5 cm) |
| Lifespan | 5-7 years |
| Temperament | Semi-aggressive, fin nipper |
| Min. tank | 20 gal (76 L) |
| Temperature | 72-79 F (22-26 C) |
| pH | 5.5-7.5 |
| Diet | Omnivore |
| Schooling | Yes, groups of 6 or more |
A blaze of red
The serpae tetra's body ranges from bright orange-red to deep blood-red, set off by a dark shoulder spot and black-edged fins. A whole school lit up together is a stunning splash of color.
The cheeky fin nipper
Serpae tetras like to nip fins. In a small group they may pester slow, long-finned tankmates, so it is best to keep them away from calm fish like bettas and to house them in a larger school.
Big group, better behavior
Keeping at least six, and ideally more, keeps their energy focused within the school. They tussle playfully with each other instead of bullying other kinds of fish.
A mock-fighting dance
Serpae tetras often flare their fins and spar with one another in a harmless show of who is boss. It looks dramatic, but it is mostly for display and rarely causes real harm in a proper group.
Hardy and colorful
They are tough, easy to feed, and adaptable to a range of water conditions, which makes them popular with hobbyists who want a bright, active fish that is simple to keep.
Fun facts
- Serpae tetras have a deep blood-red body with a black shoulder spot.
- They are known fin nippers, so tankmates must be chosen with care.
- They come from the slow streams of the Amazon basin.
- A bigger school keeps their nipping aimed at each other.
- They often stage harmless mock fights to show off.
Frequently asked questions
Why does my serpae tetra nip other fish?
Fin nipping is natural for them, especially in small groups. Keeping at least six together spreads out their energy so they bother each other instead of other fish.
Can serpae tetras live with bettas?
It is risky. Serpae tetras love to nip long, flowing fins, so slow, fancy-finned fish like bettas are usually a poor match.
How many serpae tetras should I keep?
Keep at least six, and more is better. A larger school keeps them calmer and better behaved toward the rest of the tank.
Are serpae tetras hard to keep?
No, they are hardy and easy to feed. The main thing to plan for is their fin-nipping habit when choosing tankmates.
