Types of Tetras | 9 of Our Favorites (With Pictures)

Every aquarist has heard of popular tetra species like the neon tetra, cardinal tetra, and black skirt tetra. But did you know there’s more? There are actually hundreds of different types of tetras, many of which you can keep in your aquarium. Most are stunningly colorful and easy to care for.

Here’s FantaSEA’s ode to the tetra! Today, let’s have a look at 9 of our favorite tetra species—and discover the world beyond the neon.

What’s a tetra, anyway?

What makes a fish a tetra? Well, let us start off by noting that this is not a scientific term. The denomination of “tetra” used to apply to a specific genus of fish, Tetragonopterus, but most of the species in it were moved to a wide range of other genera. No matter, because they were still all in the family Characidae… until taxonomists began chipping away at that as well, culminating in a big shake-up in 2024.

There are now seven separate tetra families. Due to all these changes, we can’t really point at one category of fish and say “those are the tetras” anymore. Sure, all seven families belong to the order Characiformes, but so do loads of other species. That includes piranhas and the huge goliath tigerfish — not exactly comparable to a little neon ntetra.

Because it’s not a scientifically defined term, aquarists and fish stores can technically slap the denomination of “tetra” on any fish. For example, there’s a species often called the “vampire tetra” (Hydrolycus scomberoides) that can grow to over a foot in length — a true monster fish with immense teeth.

All this being said, tetras are usually small and roughly share the following characteristics:

• Belong to the scientific order Characiformes
• Possess a tiny fin between the dorsal (back) and caudal (tail) fin, called the adipose fin
• Generally no more than 3″ in length
• Schooling or shoaling fish
• Usually brightly colored and patterned

There are over 150 different genera of tetras. The ones you’ll most commonly encounter in your local aquarium store include Hyphessobrycon, Hemigrammus, Paracheirodon and Moenkhausia, though there are many more to choose from.

Below, we’ll highlight some of our favorite tetras beyond the good ol’ neon. Let us know in the comments which one you like best!

Types of Tetras: FantaSEA’s 9 Favorites

Buenos Aires Tetra
(Psalidodon anisitsi)

We’re kicking off the list with the pretty Buenos Aires tetra. Unsurprisingly, this fish is naturally found in the Buenos Aires province in Argentina. This is not the limit of its range, however: it inhabits the entire La Plata river basin, which stretches into Uruguay, Paraguay, and southern Brazil.

At a maximum size of around 3″, this one’s relatively large as far as tetras go. The species sports a shimmering silvery body and characteristic red tail fin with a black spot. Some aquarium stores also carry a selectively bred albino color morph. Due to its size, the Buenos Aires tetra is best suited for an aquarium of 30 gallons (long) or larger.

This tetra is hardy and not too difficult to keep, known for its wide pH and temperature range tolerance. In fact, although it’s often considered a tropical fish, it can handle temperatures as low as 64 °F just fine! If you keep your space relatively toasty year-round, your BA tetra tank may not even need a heater.

Buenos Aires tetras can do well in community aquariums, including those with medium-sized cichlids that would eat smaller tetras; they can hold their own against Geophagus or Acaras. Do keep in mind that this species is rather active and can even turn to fin-nipping when kept alone or in small groups — get at least eight fish for the best results.

Tip: You’re likely to find this tetra for sale under its old name, Hyphessobrycon anisitsi. It was recategorized to Psalidodon in 2020, but the hobby tends to be slow to catch up.

Opening the Trojan horse: phylogeny of Astyanax, two new genera and resurrection of Psalidodon (Teleostei: Characidae)

Rummynose Tetra
(Petitella sp.)

If you’re in search of a good addition to your South American biotope tank, stop right here. The three beautiful species in the genus Petitella (two of which were formerly part of Hemigrammus), also called the rummynose tetras, are naturally found in the dark waters of the Amazon basin and will love a similar environment in your aquarium.

Keep the red-faced rummynose tetra in a tank of at least 20 gallons (long). At least eight fish works well as a minimum, though they really look their best in larger systems with 20+ rummies. Any tankmates should be calm and not bother these tranquil little tetras. Other small schooling species, as well as dwarf cichlids that hail from similar waters, make good choices.

Keep in mind that rummynose tetras are considered less hardy than some of the other species on this list. They’re sensitive to low water quality — sometimes considered “canaries” that give you an early warning when something is off — so be sure to only introduce them into a fully cycled and mature aquarium.

Ember tetra (Hyphessobrycon amandae)

Rummynose tetras still a little too big for your tank? No problem, we can still go smaller! Meet the ember tetra, which at no more than an inch or so in length might as well be a rasbora: tiny, polite, and perfect for smaller peaceful community aquariums of 15 gallons (long) and up.

Remember that a mini tetra will need tankmates that won’t stress it out or try to eat it. Small to medium-sized bottom-dwelling catfish, from the almost microscopic Asian Hara jerdoni to the chunkier South American bristlenose pleco, are almost never a bad idea. Neither are other small tetras, rasboras, and gourami or hatchetfish for the upper water layer. Dwarf cichlids also work, but avoid anything larger than an Apistogramma!

Make sure everyone thrives in the same water parameters: ember tetras hail from soft and acidic waters. Although they’ll do alright at a pH of up to 7.5, below neutral is preferred. Plenty of plants and leaf litter will help your tetras to feel at home.

Bleeding Heart Tetra
(Megalamphodus erythrostigma)

The impressive bleeding heart tetra (Megalamphodus erythostigma) was named for the striking red dot on the side of its rosy-silver body. It’s naturally found in the upper Amazon Basin, where it inhabits a typical habitat of slow-moving tributaries plenty of aquatic and riparian plants, vegetation, leaf litter, and fallen branches.

This species makes a great choice for peaceful Amazon-style community aquariums. It likes soft and acidic water* and doesn’t usually bother its tankmates, although it can show territorial aggression towards species that look too similar for its liking. We’d avoid keeping the bleeding heart with other tetras.

Because bleeding heart tetras can reach up to 2.5” in length and should be kept — like most tetras — in groups of eight or more, it’s a good idea to go for an aquarium of 30 gallons (long) or larger. This gives these active fish plenty of space to move around and show their natural territorial displays.

Did you know? If you’re squinting at “Megalamphodus“, you haven’t gone crazy. The bleeding heart tetra, as well as many other popular aquarium tetras that were formerly placed in the genus Hyphessobrycon, were moved to Megalamphodus in 2024 based on new research. It feels like some tetras, including this one, are stuck on a sort of endless taxonomical merry-go-round — it was originally described as Hemigrammus and researchers haven’t stopped fighting about its classification since.

Emperor Tetra
(Nematobrycon palmeri)

Probably the most spectacular species on this list is the appropriately named emperor tetra (Nematobrycon palmeri). Its colors —rosy-silver body, yellow-black fins, jet-black horizontal stripe and bright blue eyes — as well as the males’ impressive fins make this a gorgeous addition to your South American or general community tank.

Luckily, the emperor tetra is not just nice to look at. It’s also flexible and pretty hardy, making it easy to keep and suitable for beginning aquarists. It withstands a wide range of water conditions as long as the aquarium is fully cycled and kept clean, and will play nice with pretty much any peaceful tankmate you can think of.

Although emperors are relatively small, we’d still recommend an aquarium of at least 30 gallons (long). These regal tetras really look and act their best when kept in groups of ten or more, and they’re active swimmers that need space to move around.

You can find everything you need to know about caring for this fish in our full emperor tetra care guide.

Congo Tetra (Phenacogrammus interruptus)

Hope you brought your sunglasses! If you’re looking for an extremely flashy tetra species to add to a larger aquarium, the Congo tetra may be just the thing. The males of this species sport a veritable rainbow of hues, from silvery to blue and even orange, that shift beautifully as they move. The females aren’t quite as colorful, but still very nice to look at.

As its name suggests, this tetra doesn’t hail from South America like the species we’ve discussed so far. It’s naturally found in the Congo River, which runs from West to Central Africa. One of the larger types of tetras at 3″, it should be kept in groups of at least eight. Due to these factors, plus the Congo tetra’s active nature, we would recommend keeping these in a tank of 55+ gallons.

Congo tetras are shy and vulnerable to fin nipping, but they’re also known to be somewhat nippy themselves. For the best results, keep them with species that don’t bother them. Fish that inhabit different water layers, like catfish, should work well.

You can find out everything you need to know about this stunning tetra in our full Congo tetra care guide.

Black Neon Tetra (Hyphessobrycon herbertaxelrodi)

Like neon tetras, but want something a tiny bit more original? Consider the neon’s goth cousin: Hyphessobrycon herbertaxelrodi, better known as the black neon tetra. Although this species lacks its cousin’s bright reds and blues, it does sport a its own iridescent line. The scales inside this line, which is white in black neons (the irony!), contain guanine crystals that make them reflect much more light than normal tetra scales.

The black neon tetra is naturally found in Brazil, where it inhabits small tropical streams and tributaries. These waters are characterized by their heavy vegetation, medium flow, and usually light brown color. The species isn’t considered a blackwater specialist like neon and cardinal tetras, though, which means it’ll do well in a wider range of water parameters.

You can keep a group of 8+ black neons in an aquarium with a water volume of 20 gallons or up. They like a heavily planted tank, though be sure to leave some swimming space in the middle. Thanks to their peaceful nature, you can combine these tetras with most small fish that appreciate similar water parameters.

Did you know? Ironically given the species’ common name, an albino (and thus, white) version of the black neon tetra exists.

Diamond tetra (Moenkhausia pittieri)

Although like many aquarium fish, the diamond tetra can look a little drab in the less-than-ideal environment of an aquarium store, you’d do well not to overlook it. This is in fact an absolute stunner, named for the beautiful shimmering scales and colors it displays once it’s had some time to settle into a suitable environment.

Naturally found in Lake Valencia in the South American country of Venezuela (where it’s unfortunately considered threatened), the diamond tetra grows to a maximum length of around 2.5″. You can keep a group in an aquarium of 20 gallons (long) and up.

Diamond tetras will display the best colors in a heavily planted tank with a dark substrate and relatively dim lighting. Their shimmers look gorgeous against lush green and red vegetation! They do well in a wide range of water parameters — not just soft and acidic, but also more alkaline — and are considered peaceful. Don’t keep them with long-finned species that make attractive targets for nipping, though.

You can find everything you know about caring for your these living gems in our full diamond tetra care guide.

Rosy tetra (Megalamphodus rosaceus)

Let’s wrap up our list with another classic tetra that can be found at almost every aquarium store. This one’s a real beauty: male rosy tetras sport silver-pinkish bodies and fins splashed with reds, oranges, stark whites and deep blacks. Female rosy tetras are more silvery, but they still have some colorful markings that make them stand out from other fish.

Formerly considered part of the genus Hyphessobrycon but

The rosy tetra is naturally found in South America, specifically in the tropical countries of Guyana and Suriname. Here, it inhabits slow-flowing streams and tributaries that are usually stained very dark by tannins from wood and leaf litter.

You can keep a group of these beautiful tetras in an aquarium of 20 gallons (long) or up. The ideal would be a blackwater biotope with plenty of leaf litter and other décor; in a bare set-up, the species’ colors become washed out.

Rosy tetras aren’t known for being nippy. In fact, they’re somewhat timid, so you should avoid combining them with overly boisterous tankmates. Instead, if you want to keep rosies in a community aquarium, be sure to choose small, peaceful companions for them.

Need help?

Looking to set up your own aquarium but lack the time or knowledge to get things right? Our job is to get our hands wet so you don’t have to. FantaSEA Aquariums can set up and maintain your tank so all you have to do is enjoy it.

Ready to get started? Contact us and we can begin planning your brand new fish tank for you!