Flag Tetra

Hyphessobrycon heterorhabdus

Also known as False Ulrey's Tetra

Animalia›Chordata›Characiformes›Characidae

The Flag Tetra is a small, peaceful schooling fish native to South America, known for its distinctive black stripe running through its body and red coloration on its fins. These active little tetras are excellent for community aquariums and thrive best when kept in groups. They are hardy and relatively easy to care for, making them suitable for both beginner and experienced aquarists.

Where it's from

Native to the Amazon and Surinam river basins

Brazil, Colombia and Suriname

At a glance

Size: 1.5 in; 4 cm
Min tank: 10 gal; 38 L
Group: 6+
Temp: 75–82°F; 24–28°C
pH: 5.5-7.0
GH: 36–143 ppm; 2–8 dGH
Temperament: Peaceful
Swims: Middle
Lifespan: 3-5 yrs

Ammonia 0 ppm and nitrate under 20 ppm.

Care

Diet

Flag Tetras are omnivorous and should be fed a varied diet of high-quality flake food, micro pellets, and small live or frozen foods such as daphnia and brine shrimp. Feed small amounts 2-3 times daily, only what they can consume in a few minutes. Occasional vegetable matter like blanched spinach can supplement their diet.

Behavior

Flag Tetras are active, social fish that display schooling behavior and should always be kept in groups of at least 6 individuals. They are peaceful and non-aggressive, spending most of their time in the middle water column exploring and foraging. They are relatively hardy and adapt well to established community tanks with stable water conditions.

Breeding

Flag Tetras are egg scatterers and moderately difficult to breed in captivity. Breeding requires soft, acidic water (pH 5.5-6.5), slightly elevated temperatures around 26-28°C, and dense vegetation or spawning mops for egg placement. Separate breeding tanks with minimal current and low lighting increase success rates.

Tank mates

See all 6

Neon Tetra

Similar size and peaceful temperament, excellent schooling companions

excellent

Cardinal Tetra

Compatible size and peaceful nature, thrive in similar water conditions

excellent

Otocinclus

Peaceful bottom dweller that helps control algae without competing for food

excellent

Corydoras Sterbai

Peaceful bottom feeder that occupies different water zone

good

Dwarf Gourami

Peaceful mid-water dweller with compatible temperament

good

Fits a 10-gallon tank Beginner-friendly Peaceful

No state or federal restrictions on record.

Not legal advice, and possibly incomplete or out of date. Rules vary by state and change over time; check with your state wildlife or agriculture agency before buying, keeping or shipping it.

The care information here is written with AI help, so it can contain mistakes. Spot one? Tell us and we'll fix it. Native range: Catálogo Taxonômico da Fauna do Brasil (CC BY 4.0); Tedesco et al. 2017 (CC0).