Description
The emperor tetra is the tetra with the most presence for its size: about 4 cm, a dark central band that turns violet-blue in the light, extended fins in the male and a blue iris that sets it apart from its relative Nematobrycon lacortei.
It is endemic to Colombia and almost everything on sale is captive-bred. It is confused with the royal tetra, which is a different species: the emperor has no adipose fin and the royal does.
Behavior
Lively and peaceful, one of the best tetras for a general community tank. Males display to each other with fins spread without hurting one another; a group with more females than males works best.
It lives well with livebearers, danios, rasboras, corydoras and small bottom feeders.
Avoid housing it with much larger or very energetic fish that take its food.
Habitat
Nematobrycon palmeri is endemic to the San Juan and Atrato river basins in Colombia. It is common in slow stretches of rivers, small tributaries and backwaters, where it shares the water with other characins, gymnotids and loricariids.
A long tank with plants and cover at the sides and open space in the middle reproduces that setting well.
Tetra emperador is a schooling species, which means that in the wild it lives and moves in large, coordinated groups.
Keep at least 6 individuals so they feel comfortable and their stress level stays low.
Details
🌊 Water parameters
🐠 Minimum tank size
Breeding
An egg depositor that lays among fine plants or moss. Adults eat the eggs if they find them, so breeding is best done in a separate tank, removing the pair after spawning.
Daily live or frozen food is advised to bring it into breeding condition and show better colour.
Diet
A micropredator: in the wild it hunts insects, worms and small crustaceans.
- Staple: small-sized flake or micropellets.
- Supplement: daphnia, brine shrimp or mosquito larvae, live or frozen, daily for good colour.
On dry food alone it survives, but looks less impressive.
What about your tank?
Enter your tank's values to see only the compatible species that fit them. Litres apply to fish.
Compatible fish
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 7–8 and 26–27 °C.
They share water: pH 6–7.5 and 23–27 °C.
They share water: pH 6–7.5 and 23–27 °C.
They share water: pH 6–7.5 and 23–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 5.5–7 and 24–27 °C.
They share water: pH 6–8 and 23–26 °C.
They share water: pH 5.5–8 and 23–27 °C.
They share water: pH 6–7.5 and 25–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 6.5–8 and 24–26 °C.
They share water: pH 6–8 and 23–26 °C.
They share water: pH 6–7.5 and 23–25 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 6.5–7.5 and 23–24 °C.
They share water: pH 5–7 and 27 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 7–8 and 23–27 °C.
They share water: pH 6.5–8 and 23–27 °C.
They share water: pH 6–7.5 and 25–27 °C.
They share water: pH 6–8 and 23–27 °C.
They share water: pH 6–7.5 and 23–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 6–7.5 and 24–27 °C.
They share water: pH 5.5–7 and 24–27 °C.
They share water: pH 7.5–8 and 24–27 °C.
They share water: pH 7.5–8 and 24–27 °C.
They share water: pH 5.5–7 and 23–26 °C.
They share water: pH 5–6.5 and 23–27 °C.
They share water: pH 6.5–7.2 and 23–26 °C.
They share water: pH 6–7.5 and 23–26 °C.
They share water: pH 6.5–8 and 23–24 °C.
They share water: pH 5–7.5 and 23–27 °C.
They share water: pH 5–7 and 23–27 °C.
They share water: pH 5–8 and 23–27 °C.
They share water: pH 5–7.5 and 23–27 °C.
They share water: pH 7–8 and 23–27 °C.
They share water: pH 5.5–7 and 26–27 °C.
They share water: pH 5.5–7 and 23–26 °C.
They share water: pH 6.5–7.5 and 23–26 °C.
They share water: pH 5–6.5 and 24–27 °C.
They share water: pH 5.5–7 and 23–27 °C.
They share water: pH 5.5–7.5 and 23–27 °C.
They share water: pH 5.5–8 and 24–27 °C.
They share water: pH 6–7.5 and 23–26 °C.
They share water: pH 5.5–7.5 and 23–27 °C.
They share water: pH 5.5–7.5 and 23–27 °C.
They share water: pH 7–8 and 23–27 °C.
Compatible invertebrates
General guidance based on water parameters, behaviour and known exceptions; always review the individual animals' and aquarium's specific needs.
They share water: pH 7–8 and 23–27 °C.
They share water: pH 5.5–6.5 and 23–24 °C.
They share water: pH 6.5–7.5 and 23–27 °C.
They share water: pH 7–8 and 23–25 °C.
They share water: pH 7.5–8 and 24–27 °C.
They share water: pH 7–8 and 23–27 °C.
They share water: pH 7.5–8 and 26–27 °C.
They share water: pH 7–8 and 23–27 °C.
They share water: pH 6.5–7.5 and 23–26 °C.
They share water: pH 5.8–6.8 and 23–24 °C.
They share water: pH 5.8–6.8 and 23–24 °C.
They share water: pH 6.5–7.5 and 23–27 °C.
They share water: pH 7.5–8 and 27 °C. They only meet at the very edge, so the tank has to hold that value.
They share water: pH 7–8 and 23–27 °C.
They share water: pH 6.5–7.5 and 23–26 °C.
They share water: pH 6.5–7.5 and 23–26 °C.
They share water: pH 6.5–7.5 and 23–26 °C.
They share water: pH 6.5–7.5 and 23–26 °C.
They share water: pH 6.5–7.5 and 23–26 °C.
They share water: pH 6.5–7.5 and 23–26 °C.
They share water: pH 7–8 and 23–27 °C.
They share water: pH 7–8 and 23–27 °C.
They share water: pH 6.5–8 and 23–27 °C.
They share water: pH 7–8 and 23–27 °C.
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They share water: pH 7–8 and 23–27 °C.
Sources
- FishBaseFroese, R. and D. Pauly. Editors. 2026. FishBase. World Wide Web electronic publication.
- Seriously FishSeriously Fish. Nematobrycon palmeri. Ficha de especie; consultada 2026-10.
Water: FishBase gives pH 5-8 and 5-19 dH; Seriously Fish, pH 5-7.5 and 1-12 dGH. The profile uses the widest range: pH 5-8 and dGH 1-19.
Litres per fish and minimum tank height and depth: the profile's own judgement. Seriously Fish gives only the tank base and FishBase gives no tank sizes.
Plan your next aquarium
Is this fish right for you? Plan a suitable aquarium before setting it up.