Amapa tetra
Hyphessobrycon amapaensis
Also known as: Red line tetra, Scarlet tetra
This is a tiny, super sleek little tetra with a clean red stripe down the side that really pops once its settled in. It does best in a planted, slightly tinted "creek-style" setup and looks way cooler when you keep a proper group so they school and flash that line together. If you can give it soft, slightly acidic water and a calm community, its an easy fish to fall for.
Amapa tetras exhibit a sleek body with vibrant yellow to orange coloration and distinctive black markings on their fins.
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Quick Facts
Size
3.0 cm SL (about 1.2 inches)
Temperament
Peaceful
Difficulty
Intermediate
Min Tank Size
15 gallons
Lifespan
2.5-4 years
Origin
South America
Diet
Omnivore - small flakes/micropellets plus frozen/live foods like daphnia, artemia, and small worms
Care Notes
- Keep them in a real group (8-12+). With only a few they get shy, wash out in color, and bicker more.
- They look and act best in a planted tank with dim lighting, dark substrate, and some floating plants or leaf litter to break up the light.
- Aim for soft to moderately soft water and slightly acidic to neutral pH (around 6.0-7.2), and keep the temp in the mid-70s F (about 24-26 C). They do not love hard, high-pH tap water long term.
- Feed small foods they can actually swallow: micro pellets, crushed flakes, and frozen/live stuff like daphnia, cyclops, baby brine, and bloodworms as a treat. A couple small feedings beats one big dump that wrecks water quality.
- Tankmates: other calm small fish like Corydoras, small rasboras, pencilfish, and peaceful dwarf cichlids work well. Skip fin-nippers (some barbs) and big fast feeders that will outcompete them.
- Use a sponge prefilter or sponge filter if you have fry or tiny tankmates - these tetras will explore every intake. They appreciate gentle flow rather than a blasting river pump.
- Breeding is doable if you give them a separate tank with very dim light and fine plants or a spawning mop; adults will eat eggs. Soft, slightly acidic water helps, and the eggs and fry hate bright light so keep it shady.
Compatibility
Good Tankmates
- Other small, chill tetras in a proper group (ember tetra, glowlight tetra, black neon). Amapas are peaceful and look way more confident when everyone is schooling and nobody is trying to be the boss.
- Corydoras catfish (pandas, sterbai, peppers). Classic combo - cories do their own bottom thing, Amapas hang midwater, and nobody bothers anyone.
- Small, calm dwarf cichlids like Apistogramma (especially if the tank has plants and caves). They usually ignore the tetras, just give the apistos territory so they do not get cranky in breeding mode.
- Otocinclus in a planted tank. They are mellow algae grazers and the Amapas will just treat them like moving decor.
- Peaceful rasboras (harlequin, chili) and similar small schooling fish. Same vibe, same pace, no fin drama.
- Dwarf pencilfish (Nannostomus). They stick higher in the tank and are super non-confrontational, so it makes a really relaxed community mix.
Avoid
- Anything nippy like tiger barbs or serpae-type fin nippers. Amapas are peaceful and can get stressed out when they are being chased or their fins get sampled.
- Big or pushy fish that see small tetras as snacks (most larger cichlids, larger gouramis, bigger barbs). If it can fit a tetra in its mouth, it will eventually try.
- Fast, aggressive livebearers in overcrowded setups (some mollies, bigger platies) that are always in everybody's face. Not always a disaster, but they can outcompete the tetras at feeding time and keep them on edge.
Where they come from
Amapa tetras (Hyphessobrycon amapaensis) come from northern Brazil, around the Amapa region. Think small forest streams and side channels where the water is usually tea-colored from leaves and wood, with a gentle flow and lots of cover. If you have kept other small Hyphessobrycon, the vibe is familiar: soft-ish water, dim light, and a lot of structure.
They look toughest and color up best (in my tanks, anyway) when you copy that shady, leaf-litter stream feel rather than running a bright, bare setup.
Setting up their tank
Give them space to school and a bunch of places to dip into when they feel jumpy. A 20-long footprint works nicely for a group, but bigger is always easier if you want them calmer and more visible. They are not high-flow fish, so skip the river-tank blast.
- Group size: 10+ if you can. They act way more natural and the little pecking order stuff stays harmless.
- Filtration: gentle, steady. A sponge filter or a canister turned down with a spray bar is perfect.
- Hardscape: driftwood, branches, and a scatter of dried leaves (catappa/oak/beech) for cover and that tannin tint.
- Plants: works great. Stems and floating plants (frogbit/salvinia) help keep the light low.
- Substrate: anything, but darker sand makes them look better and they seem less skittish.
For water, aim for the usual Amazon-ish range: mid-70s F for temp, slightly acidic to neutral, and not super hard. They will live in more average community water if it is stable, but they get touchier during shipping and settling in, so consistency matters more than chasing exact numbers.
Acclimate them patiently. New imports can be a little fragile the first week or two. Low light, lots of cover, and small daily feedings beats tossing them into a bright tank and feeding heavy.
What to feed them
They are classic small tetra eaters: they will take most prepared foods, but they really pop and fill out better with some small frozen/live mixed in. If you only feed flakes, they will survive, but you will wonder why they look a bit washed out.
- Staples: a good micro pellet and/or quality flake, crushed small enough for their mouths
- Frozen: baby brine shrimp, daphnia, cyclops, and fine bloodworms (sparingly)
- Live (if you do it): baby brine shrimp, grindal worms, microworms
Go easy on rich foods (like lots of bloodworms) in a warm, small tank. It is an easy way to foul water fast, and these little tetras show stress quickly when water quality slips.
How they behave and who they get along with
Amapa tetras are peaceful schooling fish with that typical Hyphessobrycon attitude: a bit of posturing, tiny chases, and occasional fin-nips if they are kept in too small a group or in a cramped tank. In a proper-sized school they settle into a nice, tight group and spend a lot of time midwater.
- Good tankmates: other small, calm tetras, pencilfish, hatchetfish, corydoras, small loricariids, peaceful dwarf cichlids
- Use caution with: long-finned fish (slow guppies, fancy bettas) if your group is small or under-stimulated
- Avoid: big, pushy fish that make them hide all day, and anything that views them as snacks
If you want to see them out more, add dither fish that are calm and confident (other small tetras work), and keep the lighting broken up with floaters. A bright spotlight tank makes them act like they are being hunted.
Breeding tips
They are egg scatterers. Breeding is doable, but it is not a set-and-forget community tank thing because the adults will eat eggs and fry. If you have bred other small tetras, the general playbook applies.
- Breeding tank: 5-10 gallons, bare bottom, dim light, sponge filter
- Spawning media: a big clump of java moss, spawning mop, or a mesh grate so eggs fall out of reach
- Water: softer and slightly acidic helps, and a couple leaves can calm them and darken the tank
- Conditioning: feed frozen/live foods for a week or two, then try a pair or a small group
- After spawn: remove adults, keep it dark for the first day if you can
Fry are tiny, so you will need tiny foods at first. Infusoria or a commercial liquid fry food can bridge the first few days, then move to microworms and baby brine shrimp once they can take it.
If you do not see eggs, do not assume it failed. Often they spawn at first light, and the eggs can be hard to spot unless you use a bare bottom or a grid.
Common problems to watch for
Most issues I have seen with these come down to shipping stress, a too-bright tank, or water that swings around. They are not impossible, just less forgiving than the hardiest beginner tetras.
- Shyness and hiding: usually bright light or no cover, sometimes bullying from larger fish
- Fin-nipping: almost always a too-small group or not enough swimming space
- Ich after purchase: common with stressed tetras; quarantine helps a lot
- Wasting/skinny fish: watch for internal parasites on new fish, especially wild-caught shipments
- Sudden losses: often linked to ammonia/nitrite spikes or big parameter swings after a water change
Do not skip quarantine if you can help it. A small group of tetras can bring in ich or parasites and it spreads fast in a warm community tank.
My general routine is simple: stable temp, weekly water changes, feed a mix of dry and frozen, and keep them in a real school. Do that and they are a really satisfying little tetra to keep.
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