Green Fire Tetra Stats InfographicThe Green Fire Tetra, also known as Aphyocharax rathbuni, is one of the best tetras you can add to a peaceful community aquarium.

Although this species is often shadowed by the more popular Neon Tetra and Cardinal Tetra, they also have amusing idiosyncrasies and a jaw-dropping metallic color combination that will bedazzle any aquarium!

The best part is that these beautiful gems aren’t high-maintenance.

Green Fire Tetra Stats

Species Aphyocharax rathbuni
Family Characidae
Genus Aphyocharax
Care Level Beginner
Temperament Peaceful, but may nip at long flowing fins
Compatibility Small tetras and other non-aggressive species of the same size
Average Size 1.4 – 2 inches
Color & Patterns
  • Translucent, metallic emerald color
  • A hint of gold or yellow
  • A splash of red toward the anal fin
  • (Females are lackluster but still features a bloody red color toward the anal fin)
Diet Omnivore
Tank Size 15 gallons
Tank Setup
  • Dense vegetation
  • Subdued lighting
  • Aquatic soil/sand/gravel
pH 6.6 – 7
Hardness 4 – 8 dH
Temperature 72° – 80 F

Aphyocharax Rathbuni Origin, Habitat, and Distribution

C. H. Eigenmann described the Green Fire Tetra in 1907. Scientifically known as Aphyocharax rathbuni, it hails from the pristine waters of Rio Paraguay in South America. This species is also endemic to the Parana and Uruguay drainages in Brazil.

You will find large schools of this species in slow streams and calm rivers covered by floating vegetation. Trees also loom over the waters, thus providing more shade. Their habitat undergoes slight changes depending on the season. As a result, the fish have grown hardy and became adaptable to ever-changing conditions.

Green Fire Tetra Physical Characteristics

– How Big Does a Green Fire Fish Get?

Green fire tetra also known as aphyocharax rathbuniThe Green Fire Tetra is neither too big nor too small. It is a medium-sized fish that can reach up to 2 inches in length at its full maturity. However, captive specimens seldom reach this length and may max out at 1.4 inches.

– What Does a Green Fire Tetra Look Like?

As with most tetra fish, the A. rathbuni has a slender body that almost resembles a spindle.
The Green Fire Tetra, however, is one of the more unique-looking species within the tetra world.

This species displays a metallic emerald color that makes it stand out from other tetras. The green hue is followed by a hint of gold and a splash of red toward the anal fin region. The fish also has a black patch on its dorsal fin.

These green tetra fish are most colorful when they are hale and hearty. Females may appear translucent and lack shine. But, their red marks are vivid enough to give your tank a pop of color.

– Gender Differences

As with other tetra species, it can be difficult to sex the fish before they hit sexual maturity. But once they do, males develop whitened tips on their anal, pelvic, and dorsal fins. Females, on the other hand, will have a bulging belly when they are in spawning condition.

The colors of an adult Green Fire Tetra might also help you differentiate males from females. Males appear shinier, and their metallic green color is more vivid than females.

Green Fire Bloodfin Behavior and Temperament

The Green Fire Tetra is a peaceful, playful shoaling species. For them to be hale and hearty, they need to be in a school of at least six. Add more if space allows. These tetras feel safer and more confident when they are in a large group.

A happy school will swim throughout the entire tank, which is quite amusing to watch. Their name suits them well as they are a ball of fire! As an added bonus, they add a burst of color to your aquarium whenever they frolic and swirl around as a group.

But although these tetras are non-aggressive, their curiosity may sometimes get the best of them. As such, they may nibble on the flowing fins of other fish that are only passing by. So it would be wise not to house them with long-finned species that swim at a rather slow pace.

Mistaken Identity: Green Fire Tetra vs. Green Neon Tetra

Green fire tetra fishMany people assume that the Green Fire and Green Neon tetras are the same. The truth of the matter is that these are two different species of the family Characidae. Sure, the fish have a similar body shape and size. After all, they are closely related. However, that seems to be the only thing they share in common.

Scientifically known as Paracheirodon simulans, the Green Neon Tetra hails from the blackwaters of upper Orinoco and Negro Rivers in South America. But contrary to its name, the latter does not have the vivid green coloration of the Green Fire Tetra. I wonder why it is even called “green” in the first place.

Will they shoal together? No. Aside from the colors, these two tetra species differ in behavior. The Green Neon Tetra is calm, while the Green Fire Tetra is fidgety and always seems on the go.

Is the Green Fire Tetra Synonymous to Redflank Bloodfin?

The “Redflank Bloodfin” and “Rathbun’s Bloodfin tetra” both refer to the Green Fire tetra. Due to the pronounced red patches on the anal region, it is easy to see why many tropical fish enthusiasts like to call this species such names. However, some online sources would post pictures of females instead of males, which often leads to misconceptions.

Green Fire Tetra Breeding

The Green Fire Tetra is one of the easiest species to breed in captivity. These fish are group-spawning egg scatterers that breed during daylight hours.

To ensure successful breeding, experts suggest you follow these checkpoints:

– Prepare a breeding tank

The breeding tank should measure 24 x 12 x 12 inches. Fill it with soft water with a pH of 6.5. Raise the temperature by 2 or 4 F higher.

Subdue the lighting by adding dense vegetation. The fish will spawn a lot sooner in a dim environment similar to their natural habitat. Thin-leaved and floating plants, such as java moss and Cabomba, are excellent choices. These plants will also provide refuge to the fertilized eggs.

An air-driven sponge filter is also important.

– Condition your fish

Experts suggest conditioning the males and females in separate tanks to prevent accidental breeding in the main tank.

Do that and offer your fish a plethora of live foods in addition to high-quality flakes or pellets. An abundant supply of bloodworm, brine shrimp, daphnia, and tubifex will plump them up in no time.

Females will become significantly rounder when they are in their best spawning condition.

– Let the spawning commence

Spawning will start within 24 hours as soon as the adults are placed in the breeding tank. One female can produce as many as 100 eggs. You’ll need to remove the adults as soon as the spawning process ends. Otherwise, they might end up eating their offspring.

– Nurture the fry

The eggs will hatch in two to three days, and the fry will enter the free-swimming stage four to five days later. Feed the fry with infusoria or newly hatched baby brine shrimp until their diet can be supplemented with commercial fry food. The growth rate is rapid, as long as you provide them the right foods and clean water with a constant parameter.

Green Fire Tetra Tank Mates

Choosing the right tank mates for the green tetra fish is not a difficult task. Small species of tetras are most welcome.

Here’s a rundown of other species that make the best tank mates:

Due to their peaceful nature, they can cohabitate with virtually any small to medium-sized fish with the same temperament and water requirements. Of course, you don’t want to include fish that are four times larger than your tetras, lest they become dinner.

But remember this; these unassuming critters are also notorious for nipping fins, although they do not tend to get aggressive. Goldfish and other long-finned slow swimmers might be in trouble.

Green Fire Tetra Care

– Green Fire Tetra Diet

Fussy eaters are a handful. When your fish is malnourished, it won’t take long for them to succumb to illness. Searching high and low for foods your picky fish might eat could also dry out your pockets.

Fortunately, the Green Fire tetra will accept commercially prepared fish feed. These include flakes, granules, and pellets. As long as it’s edible and small enough to fit their mouths, the fish will eat it with gusto.

In the wild, the green tetra fish also obtains nourishment from insect larvae and small crustaceans. Therefore, you will also need to incorporate meat to stimulate their appetite. Regular feedings of live or frozen bloodworms, brine shrimp, daphnia, and tubifex worms will do.

– Water Parameters

After bringing your pet fish home, you’ll need to keep tabs on the temperature, hardness, and acidity of their new habitat.

The following parameters work best for these little guys:

  • pH 6.6 – 7
  • Hardness 4 – 8 dH
  • Temperature 72 – 80 F

Always have a water testing kit on hand and check the parameters at least once a week.

– Maintenance and Equipment

These green tetra fish might be robust, but that doesn’t warrant you disregarding the water quality and having them go through a hardy endurance. Being exposed to poor water conditions will always result in unpleasant outcomes.

So here’s what you should do:

  • Employ a sponge filter to help get rid of impurities

A filter is a critical component even for a small aquarium. So you should install a filter that has four to five times the water flow compared to the water capacity of your tank. For example, a 15-gallon tank would need a filter with a flow rate of at least 60 gallons per hour.

  • Perform partial water changes every week

Change 30 percent of the water each week to retain the recommended water parameters. Never skip a week. Filters are helpful, but partial water changes are a surefire way to keep ammonia and nitrate levels to a minimum. Equally important, scrape off any algae build-up in the glass.

  • Use an aquarium vacuum to eliminate large debris

Uneaten food, rotting plants, and wastes pollute the water all the same and cause ammonia to shoot up. The best way to eliminate these contaminants is to use a good-quality aquarium vacuum. You can pick up detritus from every nook and cranny with this tool, including caves, rock formations, and other hard-to-reach areas.

– Disease

As with any fish, neglected water parameters and degraded water quality are a problem. They stress out tetras and, as a result, weakens their immune system. When the immune system is compromised, the fish could get infected with Ich or fin rot.

On the positive side, there are several over-the-counter remedies you can buy to cure your fish. A large water change and a raised temperature also help stabilize the water parameters and kill the parasites that caused the disease.

– Lifespan

The Green Fire Tetra has an estimated 6-year lifespan in the wild. Captive specimens, on the other hand, usually live for about four years. As to be expected, the life span differs due to the variation of their diet, water conditions, and swimming space.

Green Fire Tank Setup

– Tank Size

Quarantine has made us so bored that we sometimes feel like banging our heads against the wall. The same goes for our pet fish if we don’t consider getting the right tank size. While it is no secret that tetras will do fine in a small tank, how small is small?

A 15-gallon tank should provide enough space for Green Fire tetras to swim, play, jump and swirl at their pleasure. But if possible, opt for a larger tank.

Besides, a bigger-sized tank allows you to accommodate more fish in the future should you change your mind. You also have more variety of plants to choose from. Above all, it takes some time for water parameters to change in a large volume of water and thus, reduces adverse outcomes brought by ammonia spikes.

– Substrate

Any substrate will do for this species since they neither burrow themselves nor forage the bottom for the food. But since they thrive best in a well-planted tank, see to it that the plants will stay in tiptop shape. A dark aquatic soil or sand would be ideal. Not only do they nourish the plants, but they also replicate the natural habitat of the fish.

– Plants and Decorations

As mentioned above, the Green Fire Tetra feels at home in a densely planted aquarium. The fish can rest among the leaves whenever they want to, so they can always feel comfortable and secure.

– Lighting

The fish do best in low-light conditions, so LED lighting is optional. But for a community aquarium, you may need one. Just make sure there are floating plants and tall background plants to obscure direct light. Don’t worry; their metallic colors will still shimmer.

– Availability and Price

Since they are easy to breed and care for, Green Fire tetras are up for grabs from almost any fish store. A pair of these beauties cost you anywhere from $5 to $7. Oftentimes, you can get a discounted price if you buy them in a large group.


Green fire tetra fish tank matesThe Aphyocharax Rathbuni or Green Fire Tetra is a perfect addition to a South American biotope. It is native to the clear, vegetated waters of the Paraguay River basin.

These green tetra fish prefer slow-moving streams and rivers shaded by floating vegetation and tree canopies in their natural habitat.

  • The Green Fire Tetra is a hardy species with strong immunity against common diseases. However, prolonged exposure to degrading water conditions and unstabilized parameters can compromise their immune system.
  • Soft water (4 – 8 dH), a constant temperature (72 – 80 F), a slightly acidic pH (6.6 – 7), and low lighting will make them feel at home right off the bat.
  • In captivity, this schooling fish should be in a group of at least six.
  • Choosing tank mates is not that big of a job since these green tetra fish are peaceful, but beware of their urge to nip. They can’t resist long, flowing fins!
  • Take into account the nutritional value of the commercial fish feed. Although these green tetra fish will eat anything, see to it that they are nourished well. Live or frozen brine shrimp, daphnia, and tubifex worms are welcome additions.
  • The Green Fire Tetra is not that difficult to breed. To increase the number of surviving fry, you’ll need to prepare a breeding tank packed with floating and fine-leaved background plants.
  • Redflank Bloodfin and Rathbun’s Bloodfin tetra are alternative names for this species. Don’t be confused.

So if you are looking for a unique group of tetras to stock your tank, you can’t do better than the Green Fire Tetra. These fish are gorgeous and easy to care for.

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