Amazon Red Tail Tetra
Aphyocharax cf. dentatus
The Amazon Red Tail Tetra (Aphyocharax cf. dentatus) is a semi-aggressive fish that's a good step up once you have a little experience. Give it a tank of at least 110 litres (29 US gallons), water held at 75-82°F, and a pH of 6-7.5. Always keep a group of at least 5 - they feel safest in numbers.
Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.
Natural distribution
South America (Amazon basin, fast-flowing waters)
- South America
Regional colours match the stocking calculator's origin map.
Amazon Red Tail Tetra Tank Setup
Give them a tank of at least 110 litres (29 US gallons). As open-water swimmers they care more about swimming length than height, so a longer tank is ideal. Keep the water at 75-82°F with a pH around 6-7.5, and avoid sudden swings. Always keep a group of at least 5 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour.
What Do Amazon Red Tail Tetras Eat?
They're not fussy eaters - feed a varied diet, rotating good-quality dry, frozen, and gel foods rather than the same thing every day, and match the food size to their mouths.
Amazon Red Tail Tetra Tank Mates
A larger-growing, uncommon characin from fast-moving Amazon tributaries. Constantly active swimmer that needs open space and current. Can be aggressive and nip fins off smaller or slow-moving tankmates - avoid any long-finned species. Its size and speed make it a good dither fish for medium South American cichlids. The Amazon Red Tail Tetra is semi-aggressive, which is the first thing to weigh up when you choose tank mates. It's a known fin-nipper, so avoid bettas, guppies, and other slow, long-finned fish. It's a shoaling fish, so settle a group of 5 or more of its own kind before adding anything else - a stressed, lonely fish is far more likely to nip or hide. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.
Are Amazon Red Tail Tetras Good for Beginners?
Doable once you test water regularly and catch problems before fish look sick. If this is your first tank, pick something more forgiving and come back later.
Amazon Red Tail Tetra - frequently asked questions
What size tank do Amazon Red Tail Tetras need?
Amazon Red Tail Tetras need a tank of at least 110 litres (29 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.
How many Amazon Red Tail Tetras should I keep together?
Keep a group of at least 5. Amazon Red Tail Tetras are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.
What water parameters do Amazon Red Tail Tetras need?
Keep them at 75-82°F with a pH of 6-7.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.
What do Amazon Red Tail Tetras eat?
Amazon Red Tail Tetras are omnivores and aren't fussy eaters. Feed a varied mix of good-quality dry, frozen, and gel foods, and match the food size to their mouths. Feed small amounts once or twice a day, and remove anything they don't eat.
Are Amazon Red Tail Tetras good for beginners?
Amazon Red Tail Tetras are best for keepers with a little experience. They are manageable once you test water regularly and catch problems early; a complete beginner may prefer something more forgiving first.
Common mistakes with Amazon Red Tail Tetras
- Buying fewer than 5 - Amazon Red Tail Tetras need a proper school to feel secure; isolated individuals hide, fail to colour up, or become stressed.
- Underestimating tank size - the minimum footprint is 110 litres (29 US gallons); impulse buying into a smaller tank leads to stress and shortened lifespan.
- Mixing with long-finned fish - Amazon Red Tail Tetras will nip at bettas, angelfish, and other fish with flowing fins, causing stress and infection risk.
Building a community? Run the full list through the stocking calculator before you add anything else.
Great tank mates
Chosen from temperament, overlapping temperature/pH bands, plausible minimum tank footprints, and size versus yours in App-aquatic data. Hobby nuance always wins - verify stocking and temperament before purchasing.
Check Amazon Red Tail Tetra against any other fish → Compares water parameters, predation risk, fin nipping and tank size, and draws both at life size.
Fish to avoid mixing with Amazon Red Tail Tetras
These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.
- OscarPredator - Oscar will eat or injure smaller tank mates
- Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
- Common GoldfishGoldfish - prefer cooler, harder water that tropical fish cannot tolerate
