Flame Tetra

Quick summary

The Flame Tetra (Hyphessobrycon flammeus) is one of the hardiest and most forgiving tetras available, making it an excellent choice for beginners and experienced aquarists alike. With its warm coppery orange and red colouration, peaceful temperament, and tolerance of a broad range of water conditions, it slots comfortably into almost any community aquarium of 60 litres or more.

🐠 Build a tank around this species

Last researched and fact-checked: June 2025.

• Introduction
• Quick Stats
• Appearance
• Natural habitat
• Tank size and setup
• Water parameters
• Filtration and equipment
• Diet and feeding
• Behaviour and temperament
• Tank mates
• Breeding
• Common diseases and health
• Frequently asked questions
• Related guides

Introduction

Few tropical freshwater fish have been part of the aquarium hobby for as long as the Flame Tetra. First imported into Europe in the 1920s, Hyphessobrycon flammeus was described by Myers in 1924 from specimens collected near Rio de Janeiro, Brazil. In the century since, it has earned a reputation as one of the most dependable and easy to keep small characins, rivalling even the Neon Tetra in terms of name recognition among newcomers to fishkeeping.

Also sold under the names Von Rio Tetra, Fire Tetra, and Red Tetra (among others), this species belongs to the family Characidae and the large, taxonomically complex genus Hyphessobrycon. Despite the genus still undergoing periodic revision by ichthyologists, the Flame Tetra’s own taxonomy is stable and well established. It is not easily confused with any other commonly traded species, though selectively bred colour morphs have appeared over the decades.

Part of its enduring popularity is its unfussiness. The Flame Tetra adapts well to a variety of water chemistries, eats virtually any food offered, breeds readily in captivity, and shows minimal aggression. At the same time, it is attractive enough to hold its own alongside more glamorous tankmates. A well-conditioned shoal in a planted aquarium, the males glowing a deep scarlet, is genuinely eye-catching and belies the species’ modest price tag.

Because the Flame Tetra has been so thoroughly documented over the past hundred years, this guide can draw on a wealth of reliable information covering everything from wild habitat conditions to detailed breeding protocols. If you are looking for a first tetra or simply want a robust, colourful addition to a peaceful community, the Flame Tetra deserves a place near the top of your shortlist.

Appearance

The Flame Tetra is a small, laterally compressed tetra with a classic diamond-shaped body profile. Adults typically reach 2.5 – 4 cm (1 – 1.6 in) in standard length, with females sometimes being slightly larger and deeper-bodied than males. The overall impression is of a warm, burnished fish whose colours intensify dramatically when the animal is in good health and condition.

The front half of the body is predominantly a silvery bronze or coppery colour, often with a subtle golden or olive sheen on the dorsal surface. Two dark, vertically oriented bars or blotches sit just behind the gill cover, one slightly in front of the other. These markings are a key identifying feature and are present in both sexes, although they can appear more or less prominent depending on the fish’s mood and background colour.

The rear half of the body transitions into the vivid reddish orange that gives the species its common name. In well-conditioned males, this colour deepens to a rich scarlet or blood-red, particularly on the anal fin, which is broad and edged with dark pigment. The dorsal fin carries a similar red flush tipped with black, while the caudal (tail) fin is more translucent with a reddish tint. The pectoral and pelvic fins are generally clear to lightly tinted.

Sexual dimorphism is reasonably easy to spot in mature specimens. Males are slimmer, more intensely coloured, and have a distinctly black-edged anal fin. The leading edge of the anal fin in males may also appear slightly hooked or thickened. Females are rounder in profile when viewed from above, paler overall, and lack the bold black edging on the anal fin. When gravid, females show a noticeably distended belly.

Several selectively bred variants exist in the hobby. A “gold” or “albino” form lacks much of the dark pigmentation, and a more deeply red-selected strain is sometimes marketed as the “super red” or “orange” Flame Tetra. These are the same species and require identical care. Wild-type fish, however, remain the most commonly available and arguably the most attractive form.

Natural habitat

The Flame Tetra is native to coastal river drainages in the state of Rio de Janeiro in south-eastern Brazil. Its type locality is specifically the area around the city of Rio de Janeiro itself, including tributaries of the Guanabara Bay drainage and surrounding small coastal river systems. This is a relatively restricted natural range compared to many other popular aquarium tetras.

In the wild, the species inhabits slow-moving streams, small rivers, and their associated backwaters, typically in areas with abundant aquatic and marginal vegetation. The substrate in these habitats is often sandy or muddy, with deposits of leaf litter and submerged wood. Water conditions tend towards soft and slightly acidic, though the coastal lowland drainages around Rio de Janeiro can be variable. Recorded parameters from collection sites generally indicate pH values between roughly 6.0 and 7.5, with relatively low mineral content.

These habitats are subtropical rather than truly tropical, meaning temperatures fluctuate seasonally more than in the Amazon basin. Water temperatures may drop below 20 °C (68 °F) during cooler months, which partly explains the Flame Tetra’s tolerance for a wider temperature range than many of its congeners. The species is found alongside other small characins, and its diet in the wild consists of small invertebrates, insect larvae, algae, and organic detritus.

Although the IUCN currently lists Hyphessobrycon flammeus as Least Concern, its restricted natural range places it in proximity to one of the most densely urbanised regions in South America. Habitat degradation from pollution, deforestation, and urban expansion is an ongoing concern. Virtually all Flame Tetras sold in the aquarium trade today are commercially bred, with significant numbers produced in farms in Eastern Europe and South-East Asia. Wild-caught specimens are uncommon in the UK hobby.

Tank size and setup

A minimum tank size of 60 litres (approximately 13 UK gallons) is appropriate for a small group of Flame Tetras. This provides enough swimming space for a shoal of six to eight fish with room for plants and decor. For larger groups of ten or more, or for a mixed community, a tank of 80 – 120 litres (18 – 26 UK gallons) or above is preferable and will allow the fish to display more natural shoaling behaviour.

The tank should ideally have a rectangular footprint rather than a tall or novelty shape, as Flame Tetras use horizontal swimming space more than vertical height. A standard 60 cm (2 ft) tank is a good starting point, with longer tanks of 80 – 90 cm (approximately 3 ft) being even better for a community setup.

Planting is highly recommended. In the wild, Flame Tetras are associated with vegetated habitats, and live plants serve multiple purposes in the aquarium: they provide cover, reduce stress, help stabilise water quality, and bring out the best colour in the fish. Good choices include Vallisneria, Cryptocoryne, Java Fern (Microsorum pteropus), Java Moss (Taxiphyllum barbieri), and various stem plants such as Hygrophila or Rotala. A mixture of background stem plants with midground rosette plants and foreground mosses or carpeting plants creates an attractive, functional layout.

Leave an open swimming area in the centre or front of the tank. Flame Tetras are active swimmers and will spend much of their time in the middle water column if given space to do so. Floating plants such as Amazon Frogbit or Salvinia can be used to diffuse overhead lighting, which tends to make tetras feel more secure and brings out more intense colouration.

Substrate choice is flexible. A fine, dark gravel or sand substrate will show off the fish’s colours best. Light-coloured substrates are not harmful, but tetras typically appear somewhat washed out against them. If keeping live plants, a nutrient-rich planted aquarium substrate or a capped soil substrate will support plant growth more effectively than inert gravel alone.

Include some pieces of bogwood or driftwood and, optionally, dried leaf litter (Indian almond leaves or oak leaves) to provide additional cover and to release tannins that gently lower pH and tint the water. This is not essential for Flame Tetras, which are adaptable, but it more closely replicates their natural environment and can contribute to a very natural-looking display.

A secure, well-fitting lid or cover glass is advisable. While Flame Tetras are not habitual jumpers, any small tetra can leap from the water if startled, and an open-top tank in a room with fluctuating temperatures also loses heat and humidity more quickly.

Water parameters

The Flame Tetra is notably tolerant of a wide range of water conditions, which is a major part of its appeal as a beginner fish. It will thrive in soft, acidic water typical of its native habitat, but also adapts well to the moderately hard, neutral to slightly alkaline tap water found in many parts of the UK. Aim for the following parameters:

Stability matters more than hitting a precise number within those ranges. Avoid sudden swings in temperature or pH, and ensure the tank is fully cycled before adding fish. While the Flame Tetra is hardier than many small tetras, it is still sensitive to ammonia and nitrite, both of which should always read zero in a properly maintained aquarium.

An ideal temperature for general keeping is around 24 – 26 °C (75 – 79 °F). The species can tolerate temperatures somewhat below 22 °C (72 °F) for short periods, reflecting its subtropical origins, but sustained exposure to very low temperatures is not recommended. Conversely, temperatures above 28 °C (82 °F) may be tolerated briefly (for example during disease treatment) but should not be maintained long-term, as warmer water holds less dissolved oxygen and can stress the fish.

For most UK tap water supplies, the Flame Tetra will do perfectly well without any modification. If your local water is very hard (above 15 – 18 dGH) and you wish to keep conditions more natural, mixing tap water with RO (reverse osmosis) water at water changes is an option, but it is not strictly necessary for general keeping. Breeding, however, is more successful in softer, more acidic water.

Carry out regular partial water changes of 20 – 30% per week to keep nitrates low and water quality high. Use a dechlorinator or water conditioner whenever adding tap water to the tank.

Filtration and equipment

Flame Tetras do not have any unusual filtration requirements. A standard internal filter, hang-on-back filter, or small external canister filter rated for the tank’s volume will work well. The filter should provide gentle to moderate flow. While Flame Tetras are not weak swimmers, they naturally inhabit slow-moving waters and will be more comfortable without a strong current blasting across the tank. If your filter produces a powerful output, use a spray bar, lily pipe, or baffle to diffuse the flow.

Biological filtration is the priority. Ensure the filter has adequate capacity for biological media (ceramic rings, sintered glass, or sponge) to support the nitrogen cycle. Mechanical filtration (filter floss or fine sponge) keeps the water clear, and chemical filtration (activated carbon) is optional and only necessary if you need to remove medications or specific pollutants from the water.

A reliable aquarium heater is essential in most UK homes, as room temperatures will frequently drop below the species’ comfortable range, particularly overnight and during winter. A heater rated at approximately 1 watt per litre is a good rule of thumb. Set it to around 24 – 26 °C (75 – 79 °F) for general keeping. A separate thermometer (digital or glass) allows you to verify the heater’s accuracy independently.

Lighting should be appropriate for any live plants you are growing but does not need to be particularly intense for the fish themselves. Flame Tetras tend to show their best colour under moderate lighting, especially if floating plants are used to create some dappled shade. Standard LED aquarium lights on a timer set for 8 – 10 hours per day suit both the fish and most common aquarium plants.

An air pump is not required if your filter provides adequate surface agitation for gas exchange, but can be useful in warmer weather or if you are running a densely stocked tank where dissolved oxygen levels might drop.

Diet and feeding

The Flame Tetra is an omnivore with a broad and unfussy appetite. In the wild, it feeds on small invertebrates, insect larvae, algae, plant matter, and organic detritus. In the aquarium, it will accept virtually any food of appropriate size.

A good quality micro-pellet or small flake food should form the staple diet. Choose a product formulated for tropical community fish or specifically for small characins. Flake food is readily taken from the surface and as it sinks through the water column. Micro-granules or slow-sinking pellets are also excellent, as they keep food in the mid-water zone where the fish naturally feed.

Supplement the staple diet regularly with live or frozen foods. Daphnia, baby brine shrimp (Artemia nauplii), bloodworm (chironomid larvae), mosquito larvae, cyclops, and Moina are all eagerly consumed and provide valuable protein and fat, particularly for conditioning fish for breeding. Frozen foods are convenient and widely available from aquarium shops in the UK. Live foods, if you can source or culture them, are even better for stimulating natural feeding behaviour and conditioning.

Vegetable matter is appreciated too. Blanched spinach, spirulina-based flakes or wafers, and the occasional small piece of blanched courgette or cucumber can be offered. Many quality flake and pellet foods already include vegetable and algal ingredients, so additional supplementation is a bonus rather than a necessity.

Feed once or twice daily, offering only as much food as the fish can consume within two to three minutes. Overfeeding is one of the most common mistakes in fishkeeping and leads to poor water quality, obesity, and associated health problems. Flame Tetras have small stomachs, and several small meals are better than one large one if your schedule allows. One fast day per week (no feeding) is practised by some hobbyists and is generally considered beneficial, although it is not strictly required.

Behaviour and temperament

The Flame Tetra is a peaceful, sociable species that is well suited to community aquariums. It is a shoaling fish and should always be kept in a group. A minimum of six individuals is recommended, with eight to twelve or more being preferable. In larger groups, the fish feel more secure, display more natural behaviour, and males tend to colour up more intensely as they compete gently for the attention of females.

Within the shoal, males will engage in minor sparring and display behaviour, flaring their fins and intensifying their colour to assert dominance. This is normal and virtually never results in injury. A group with a roughly even sex ratio, or slightly more females than males, ensures that these interactions remain spread across the group rather than being focused on one or two individuals.

Flame Tetras occupy primarily the middle water column but will move throughout the tank, feeding at the surface, exploring decor, and occasionally investigating the substrate. They are active during the day and rest at night, often hovering motionless among plant stems or in sheltered spots. They are not territorial and do not defend specific areas of the aquarium.

Stress behaviours to watch for include persistent hiding, clamped fins (fins held tightly against the body), pale or washed-out colouration, and erratic swimming or flashing (rubbing against surfaces). These can indicate poor water quality, disease, or bullying from incompatible tankmates. A well-kept group in a suitably planted tank will be confident, active, and vividly coloured.

Flame Tetras are not known to nip the fins of other fish, which makes them a safer choice than some other tetra species (such as Serpae Tetras) for keeping alongside long-finned tankmates. However, very slow-moving or extremely long-finned fish such as some fancy guppy strains may still occasionally attract unwanted attention from any tetra, so observe interactions when first introducing new companions.

Tank mates

The Flame Tetra’s peaceful nature and moderate size make it compatible with a wide range of community fish. Ideal companions are similarly sized, non-aggressive species that share comparable water parameter preferences. Avoid anything large enough to eat a small tetra, or any highly territorial or aggressive species that would bully or stress them.

Good tank mates

• Neon Tetra, a classic small tetra with overlapping water requirements and a peaceful disposition
• Ember Tetra, a tiny, gentle tetra that contrasts nicely in colour and occupies a similar water column zone
• Cardinal Tetra, another peaceful characin that thrives in soft, slightly acidic conditions
• Harlequin Rasbora, a hardy, easygoing rasbora that makes a superb community companion
• Cherry Barb, a peaceful barb with a complementary warm red colour and similar care requirements
• Panda Corydoras, a small, sociable bottom-dweller that helps clean up uneaten food
• Bronze Corydoras, a robust and widely available catfish ideal for the lower levels of a community tank
• Otocinclus, a small algae-eating catfish that is peaceful and unobtrusive
• Kuhli Loach, a peaceful, nocturnal bottom-dweller that adds variety without conflict
• Amano Shrimp, a useful algae-eating invertebrate that is too large for adult Flame Tetras to bother

Fish to avoid

• Oscar, a large, predatory cichlid that will eat small tetras without hesitation
• Convict Cichlid, a territorial and aggressive cichlid that will harass and potentially kill small tankmates
• Jack Dempsey, another large, aggressive cichlid completely unsuitable for a tetra community
• Red-tail Catfish, a massive predator that will consume anything it can fit in its mouth
• Green Terror, a large, belligerent cichlid that poses a serious threat to small fish
• African Jewel Cichlid, a territorial species that becomes especially aggressive when breeding
• Serpae Tetra, a notoriously nippy tetra that may harass calmer tankmates including Flame Tetras
• Bucktooth Tetra, an aggressive, scale-eating characin that is dangerous to almost all community fish
• Common Pleco, not aggressive but grows far too large for the tank sizes suited to Flame Tetras
• Chinese Algae Eater, becomes territorial and aggressive as it matures and may harass small fish

Breeding

The Flame Tetra is one of the easier egg-scattering tetras to breed in captivity, and successful spawning has been documented by hobbyists and breeders for nearly a century. With a little preparation, breeding can be achieved even by relatively inexperienced fishkeepers.

To condition a breeding group, separate the sexes for one to two weeks beforehand if possible, and feed them a high-quality diet rich in live or frozen foods such as daphnia, baby brine shrimp, and bloodworm. This mimics the abundance of food that triggers spawning in the wild and helps females fill with eggs. Ripe females will appear noticeably plumper when viewed from above.

Set up a separate breeding tank. A small tank of 20 – 30 litres is sufficient. The water should be soft and slightly acidic, ideally around pH 6.0 – 6.5 with a general hardness of 2 – 8 dGH and a temperature of 25 – 27 °C (77 – 81 °F). Use mature, dechlorinated water, and consider adding peat extract or Indian almond leaves to soften and acidify the water naturally. Lighting should be dim.

The bottom of the breeding tank should be covered with a spawning medium that protects the eggs from being eaten by the parents. Fine-leaved plants such as Java Moss or spawning mops work well, as does a layer of glass marbles or a mesh grid positioned just above the tank floor. The goal is to allow the eggs to fall through to safety while preventing the adults from reaching them.

Introduce a conditioned pair (or a small group of two males and three to four females) to the breeding tank in the evening. Spawning typically occurs the following morning, often at first light. The male courts the female with fin displays and chases, and the pair scatters eggs among the plants or spawning medium. A single female can produce 100 – 200 eggs or more in a single spawning event. The eggs are small, semi-transparent, and slightly adhesive.

Remove the adults from the breeding tank as soon as spawning is complete, as Flame Tetras, like most egg-scattering characins, will readily eat their own eggs and fry if given the opportunity. Eggs typically hatch within 24 – 36 hours at breeding temperatures. The fry are tiny and will initially survive on their yolk sacs for a further one to two days before becoming free-swimming.

Once free-swimming, the fry should be fed infusoria or commercially available liquid fry food for the first few days. After about a week, they can usually take newly hatched brine shrimp (Artemia nauplii) and finely powdered dry food. Growth is steady, and the fry begin to show colour at a few weeks of age, becoming recognisable as Flame Tetras by about six to eight weeks. Maintain excellent water quality in the fry tank with gentle sponge filtration and frequent, small water changes using water matched to the tank’s temperature and chemistry.

Common diseases and health

The Flame Tetra is a robust species that is not especially prone to any particular disease beyond those that affect freshwater tropical fish in general. The most commonly encountered problems are ich (white spot disease), caused by the parasite Ichthyophthirius multifiliis, and various bacterial or fungal infections that typically arise as secondary problems when fish are stressed or kept in poor water conditions. Ich presents as small white cysts on the body and fins, and is readily treated with proprietary white spot remedies available from UK aquarium shops, usually combined with a gradual temperature increase to 28 – 30 °C (82 – 86 °F) to accelerate the parasite’s life cycle.

Fin rot, characterised by frayed, disintegrating fin edges that may appear reddened or whitish, is almost always linked to poor water quality or physical damage from nipping tankmates. Improving water quality through more frequent water changes and removing the source of stress is the first line of treatment. Antibacterial medications may be needed in more advanced cases. Fungal infections, visible as cotton-wool-like growths on the body or fins, are similarly treated with appropriate antifungal remedies after addressing the underlying cause.

Neon Tetra Disease (caused by Pleistophora hyphessobryconis, a microsporidian parasite) can potentially affect Flame Tetras, though it is less commonly reported in this species than in Neon Tetras themselves. Symptoms include loss of colour, cysts or pale patches on the body, erratic swimming, and emaciation. There is no reliable cure, and affected fish should be isolated to prevent spread. The best defence against all of these conditions is prevention: maintain excellent water quality, avoid overstocking, quarantine new arrivals for two to four weeks before adding them to an established tank, and source fish from reputable suppliers. A healthy Flame Tetra kept in appropriate conditions can be expected to live for three to five years, with some individuals exceeding this.

Frequently asked questions

How many Flame Tetras should I keep together?

A minimum group of six is recommended, but eight to twelve or more is better. Larger groups are more confident, display more natural behaviour, and allow males to colour up as they engage in harmless competition. Keeping fewer than six often results in shy, pale fish that spend most of their time hiding.

Can I keep Flame Tetras in an unheated tank?

In a consistently warm room that does not drop below about 20 °C (68 °F), it is theoretically possible, as the species originates from subtropical Brazil and tolerates cooler temperatures better than many tropical fish. However, in most UK homes, temperatures fluctuate enough (especially overnight and in winter) that a heater is strongly recommended to maintain stability and keep conditions within the ideal range.

Are Flame Tetras fin nippers?

Flame Tetras are generally not considered fin nippers. They are markedly less nippy than related species such as the Serpae Tetra. Keeping them in a proper shoal further reduces any tendency towards nipping, as their social interactions are directed within the group. They are a good choice for community tanks that include long-finned species, though caution is always advisable when mixing any tetra with very slow-moving, elaborate-finned fish.

Will Flame Tetras eat shrimp?

Adult Flame Tetras may prey on very small shrimp, particularly newborn cherry shrimp or other dwarf shrimp fry. Adult Amano Shrimp and larger cherry shrimp are generally safe, but if you are breeding shrimp in the same tank, expect some predation on the smallest juveniles. Providing dense plant cover such as Java Moss gives shrimp fry places to hide and improves survival rates.

What is the difference between a Flame Tetra and a Serpae Tetra?

Although both are red-hued Hyphessobrycon species, they are distinct. The Serpae Tetra (Hyphessobrycon eques) is deeper-bodied, more intensely red across the entire body, typically has a single prominent dark shoulder spot (rather than two vertical bars), and is noticeably more aggressive and nippy. The Flame Tetra is more coppery-orange grading to red at the rear, has the characteristic two dark vertical bars behind the gill cover, and is considerably more peaceful.

Do Flame Tetras need a planted tank?

Plants are not strictly essential, but they are highly beneficial. Live plants provide shelter, reduce stress, improve water quality by absorbing nitrates, and bring out the best colour in the fish. A densely planted tank with open swimming space in the centre will showcase a shoal of Flame Tetras at their finest. If live plants are not practical, silk or realistic artificial plants can provide some of the same cover benefits.

How can I tell males from females?

Males are slimmer, more intensely coloured (

Related guides

• Serpae Tetra
• Ember Tetra
• Black Phantom Tetra
• Lemon Tetra
• Head and Tail Light Tetra
• Bleeding Heart Tetra