The flame tetra, commonly referred to as the von rio tetra or fire tetra, is a vibrant freshwater fish that captivates aquarists with its striking colors. Belonging to the Characidae family, these fish often appear pale in pet shops due to the stress of confinement. However, once introduced to a suitable home environment with optimal conditions, their brilliant hues return. Flame tetras thrive in well-planted aquariums with gentle currents and prefer to be kept in groups. Their peaceful nature makes them excellent companions for other small fish, such as neon tetras and rasboras, enhancing community tank dynamics.
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Habitat in the wild
The Characidae family is one of the largest fish families, boasting a rich diversity of species that thrive in freshwater habitats throughout South America. Within this family, the Hyphessobrycon genus is notable, comprising over 40 small fish species that predominantly inhabit the Amazon River basin. A unique characteristic of this genus is the absence of scales on the underside of the caudal fin. The name “Hyphessobrycon,” rooted in ancient Greek, translates to “small-sized,” while “flammeus,” the species name, means “flame color” in Latin, aptly reflecting its vibrant appearance.
Flame tetras are native to the upper Paraguay River basin, particularly in Brazil, Paraguay, and Argentina. They flourish in coastal waters with temperatures ranging from 22 to 28 °C (72–82 °F), a pH level of 5.8 to 7.8, and a water hardness of 5 to 25 °dH. Unfortunately, the rivers they inhabit flow through some of Brazil’s most populated and industrialized regions, facing significant ecological threats. These threats include habitat degradation due to dam construction, water pollution, and the introduction of non-native species. The last confirmed sightings of flame tetras in the Rio de Janeiro area were recorded in 1992, and although they have been listed as a species of concern since 2004, their exact status remains uncertain.
In their natural habitat, flame tetras prefer small, shallow tributaries with depths of less than 50 cm and slow currents, often surrounded by dense vegetation. They thrive in clean, transparent, or slightly brownish waters with sandy bottoms, which offer them hiding spots from predators. In the wild, these fish are social creatures, typically found in tight-knit schools that enhance their chances of survival. Their diet is omnivorous, consisting of worms, small insects, crustaceans, and various types of plant matter. In an aquarium setting, offering a varied diet including high-quality flakes, frozen foods, and plant-based options can help maintain their vibrant colors and overall health.
Description
Flame tetras (Hyphessobrycon flammeus) are relatively small fish, typically growing to about 1.5 inches (3.8 centimeters) in length. Both males and females are similar in size, with no significant differences in appearance or dimensions. Their compact size makes them ideal for smaller aquarium setups or community tanks where space is limited. Keeping flame tetras in groups not only creates a visually appealing display but also promotes their natural schooling behavior, enhancing their overall vitality.
Lifespan
In captivity, flame tetras generally have an average lifespan of 3 to 5 years. However, with proper care, optimal tank conditions, and a balanced diet, they can occasionally live up to 6 years or even longer. Ensuring stable water parameters and a stress-free environment is crucial for maximizing their lifespan.
Physical Characteristics
The body shape of flame tetras is characteristic of all tetra species, being tall and flattened from the sides. They feature a large anal fin that extends beyond the dorsal fin, adding to their distinctive profile. The prevailing coloration of flame tetras ranges from brown and olive-green, with a silvery front that may have a yellowish sheen. Prominent features include 2 to 3 vertical dark stripes behind the head that do not extend to the back or abdomen. The body is adorned with various shades of red, from pale pink to bright red, which covers the area from the dorsal fin to the base of the caudal fin. Most fins share this coloring, while the pectoral and fatty fins are transparent, edged with a thin dark stripe that darkens during spawning.
Environmental Influence on Coloration
The environment in which flame tetras live significantly impacts their coloration. Under optimal conditions, including proper overhead lighting, these fish exhibit vibrant and stunning colors. However, even minor stress or unsuitable tank conditions can lead to fading, diminishing their attractiveness. Therefore, maintaining a well-balanced environment is essential for preserving their vivid hues.
Line Breeding and Hormonal Enhancement
Beyond their decorative value, flame tetras are of interest for line breeding. They are one of the few species that can successfully undergo color enhancement through hormone administration. These substances can be administered through food or dissolved in tank water, resulting in brighter, more saturated colors. Interestingly, even juvenile flame tetras can achieve brightness comparable to that of mature breeding individuals.
Drawbacks of Hormonal Enhancement
While the visible effects of hormonal enhancement can be striking, this method comes with drawbacks. Fish that undergo artificial color enhancement often exhibit decreased vital capacity, leading to higher mortality rates. Importantly, the hormones used for coloring do not affect the fish’s reproductive function; breeders remain active, and the quality of their offspring remains consistent with pre-treatment levels. This aspect is crucial for maintaining genetic integrity in breeding programs.
| Characteristic | Description |
|---|---|
| Common Name | Flame Tetra, Von Rio Tetra, Fire Tetra |
| Scientific Name | Hyphessobrycon flammeus |
| Family | Characidae |
| Origin | South America (Brazil, Paraguay, Argentina) |
| Size | Approximately 1.5 inches (3.8 centimeters) |
| Lifespan | Average 3 to 5 years (can live up to 7 years or longer) |
| Water Parameters | Temperature: 72°F – 82°F (22°C – 28°C) |
| pH: 5.0 – 7.0 | |
| Water Hardness: Soft to slightly acidic | |
| Behavior | Peaceful, shoaling fish |
| Diet | Omnivorous, feeds on small invertebrates and plant matter |
| Compatibility | Generally compatible with other peaceful fish |
| Sexual Dimorphism | Minimal, females may appear slightly larger and have a rounder belly when carrying eggs |
| Breeding Behavior | Males exhibit more vibrant coloration, become territorial, and actively court females |
| Recommended Tank Size | At least 10 gallons for a small group |
| Tank Setup | Well-planted with hiding spots and open swimming areas |
| Special Considerations | Provide a balanced diet and maintain good water quality |
Difficulties in keeping
The success of flame tetra in aquarium hobby is due to the fact how easily it adapts to various tank conditions as well as to its relative persistence to diseases. The fish is quite often recommended to beginner aquarists.
As many other fish kinds which in the wild inhabit in untouched, virgin areas, flame tetra can’t stand any accumulation of organic substances in a tank and requires clean tank water. This means that weekly water renews are part of your routine here. Another thing you have to keep in mind is, that you should put tetras only into a tank with a stable biological balance in it.
Keeping in a tank
Water parameters
The flame tetra is a relatively undemanding species, making it an excellent choice for both novice and experienced aquarists. Creating and maintaining suitable tank conditions is straightforward, as they closely resemble their natural habitat. To ensure optimal health and vibrant coloration, the water temperature should be maintained between 22 to 28 °C (72–82 °F). Additionally, the pH level should range from 5.8 to 7.8, and water hardness should fall between 5 to 25 °dH. Over time, flame tetras have adapted to various water parameters, including harder water conditions commonly found in commercial breeding setups.
Maintaining clean and fresh water is crucial for the wellbeing of flame tetras. Regular water changes—typically 10-20% weekly—help keep the water parameters stable and prevent the buildup of harmful substances. Installing a quality water filter is essential for efficient biological filtration, which removes toxic nitrogen compounds that can accumulate from decaying organic matter, uneaten food, and fish waste.
Excessive levels of nitrogen compounds can be detrimental to the health of flame tetras. Signs of stress include increased anxiety, loss of appetite, and attempts to jump out of the tank. Therefore, regular monitoring of water quality, including ammonia, nitrite, and nitrate levels, is important to ensure a healthy environment.
Tank size
Flame tetras thrive best when kept in schools of at least 7 individuals, as this mimics their natural behavior and helps reduce stress. For a small group of flame tetras, a minimum tank size of 10 gallons (38 liters) is generally recommended. However, opting for a larger tank is always advantageous. A spacious aquarium not only provides ample swimming space but also promotes stability in water conditions, which is crucial for the health of the fish.
If you intend to maintain a larger school or incorporate other compatible fish species in a community setup, consider a tank size of 20 gallons (75 liters) or more. This additional space allows for better distribution of territorial behaviors and minimizes competition for resources. The larger the school of flame tetras, the more room they require to swim freely and exhibit their natural schooling dynamics.
Tank decor
Creating a suitable environment for flame tetras involves providing not just sufficient swimming space but also incorporating plants, driftwood, and hiding spots. They appreciate a well-structured tank that offers areas for exploration, social interaction, and retreat from perceived threats. Dense plantings help mimic their natural habitat, allowing them to engage in foraging behaviors and providing security.
The flame tetra looks especially appealing in tall thickly planted tanks. When decorating a tank you should foresee some free space for the fish to swim. You can create small glades among the aquarium plants, so it will be seen how the fish school swims through the front glass of the tank.
It is desirable to put dry leaves on the tank bottom. They will make the tank water light brown and it will look like tetra natural habitat. You should replace the leaves once in two weeks, which can be done together with water renews.
Substrate
Choosing the right substrate for your flame tetra tank depends on personal preference, the specific needs of the fish, and the overall aquascape you wish to create. Fine gravel or sand is commonly recommended for flame tetra habitats. These substrates not only provide a natural appearance but also facilitate easy maintenance, as they allow for efficient waste removal and minimize debris buildup.
Fine gravel creates a gentle and inviting environment, enabling the flame tetras to exhibit natural behaviors such as foraging and exploring. Sand, on the other hand, can be particularly beneficial for these fish, as it mimics the soft, organic bottoms found in their native habitats. Both substrate types are gentle on their delicate fins, reducing the risk of injury during swimming.
Additionally, when selecting substrate, consider the potential for plants if you plan to incorporate live vegetation. A substrate that promotes healthy root growth, such as nutrient-rich soil or specific plant substrates, can enhance the overall health of your tank ecosystem.
Diet
Flame tetras are omnivorous fish with a notably varied diet, thriving on small spineless species, crustaceans, filamentous algae, and organic detritus in their natural habitat, which includes the Amazon River basin. In an aquarium setting, they adapt well to high-quality artificial foods, such as flake or pellet options specifically formulated for tropical fish. These foods should provide a balanced combination of animal protein, including fish or shrimp, along with essential plant-based ingredients to meet their nutritional needs effectively.
To promote optimal health and vibrant coloration, flame tetras benefit from a diverse diet that incorporates live and frozen foods like bloodworms, tubifex, and daphnia. These protein-rich treats not only enhance their diet but also stimulate natural foraging behaviors. It’s crucial to feed flame tetras small portions multiple times a day instead of one large feeding, as this approach helps prevent overfeeding and maintains good water quality in the tank. Additionally, monitoring their behavior, such as their eagerness to eat or any signs of leftover food, can provide valuable insights into their feeding habits, allowing you to adjust portions as necessary to ensure they receive adequate nutrition.
Tank mates
Are flame tetras aggressive or fin nippers? No. Flame tetras are generally peaceful fish that can coexist with a variety of compatible tank mates. However, it’s important to consider their relatively small size and gentle nature when selecting tank mates to ensure a harmonious community aquarium. Here are some suitable tank mates for flame tetras:
- Harlequin Rasboras (Trigonostigma heteromorpha)
- Neon Tetras (Paracheirodon innesi)
- Ember Tetras (Hyphessobrycon amandae)
- Glowlight Tetras (Hemigrammus erythrozonus)
- Black Neon Tetras (Hyphessobrycon herbertaxelrodi)
- Cardinal Tetras (Paracheirodon axelrodi)
- Rummy Nose Tetras (Hemigrammus rhodostomus)
- Dwarf Gouramis (Trichogaster lalius or Trichogaster chuna)
- Sparkling Gouramis (Trichopsis pumila)
- Celestial Pearl Danios (Danio margaritatus)
- White Cloud Mountain Minnows (Tanichthys albonubes)
- Dwarf Rasboras (Boraras spp.)
- Endler’s Livebearers (Poecilia wingei)
- Guppies (Poecilia reticulata)
- Platies (Xiphophorus spp.)
- Corydoras Catfish (Corydoras spp. – pygmy cory, panda cory, adolfoi catfish)
- Otocinclus Catfish (Otocinclus spp.)
- Bristlenose Plecos (Ancistrus spp.)
Never keep tetra with large sized fishes (oscar fish, jaguar cichlid, green terror, convict cichlid, Jack Dempsey fish).
Flame tetras thrive in groups of seven or more, as this schooling behavior provides them with a sense of safety and reduces stress. When kept in a larger school, they exhibit more natural behaviors, including social interactions and the establishment of a hierarchy within the group, which can be fascinating to observe.
In community aquariums, maintaining a ratio of multiple females to each male can help minimize aggression and create a more balanced environment. However, sexing individual flame tetras is not always necessary for a typical community setup. Their peaceful nature allows them to coexist harmoniously, regardless of gender, making them an excellent choice for mixed-species tanks. This compatibility contributes to a lively and dynamic aquarium, where the flame tetras add both color and activity.
Gender differences: male vs female
Distinguishing between male and female flame tetras can be quite challenging due to their minimal sexual dimorphism, but several subtle characteristics can assist in differentiating between the sexes.
Size is one aspect, as adult males typically have a less pronounced body height compared to females. Males generally measure slightly smaller, reaching about 1.5 inches in length, while females can be a bit more robust. In terms of coloration, males showcase vibrant red fins that transition smoothly into a ruddy hue, often appearing more striking in well-lit tanks. A distinctive black stripe runs along the lower edge of the anal fin in males, which is completely absent in females. Additionally, males possess black tips on their abdominal fins and transparent caudal fins, whereas females have these areas colored in a soft pink, which may not be as visually distinct.
Behavior can also provide clues, especially during breeding periods. Males often display more vibrant colors when courting, becoming more territorial as they chase females and engage in elaborate displays. These displays can include fin flaring and swimming in circles around potential mates, although such behaviors can be subtle and may not always be easily observed in a busy community setting.
Breeding
Provided with proper feeding and care females become reproductive at the age of 6-8 months and the males – at the age of 8-12 month, correspondingly.
Females and males should be kept separately for a week before spawning. It can be done by separating the tank into two sections with a net or other kind of separator or you can put the breeders into different tanks. During this period of time you should feed the flame tetra high with live food.
The main condition of successful spawning is to prepare the tank water properly. This is what should be done in advance, at least one week before the spawning starts.
You should mix tap water and distilled or osmotic water in equal proportion; then add peat extract into the mixture (in an amount of 20 drops for each 10 liters of water).
Hardness of spawning water has should be about 4—4,5 dGH and it should be slightly acidic pH 6,0—6,5.
Use glass tanks of at least of 5 liters (1 US gal) capacity as spawning tanks.
Spawning tank should be illuminated with a lamp with energy equivalent to 25 W installed at the distance of 20—30 cm from the tank. Tank water temperature should be maintained at about 25—26 °C. To protect eggs put a separation net or a bush of a small leaved tank plant on the spawning tank bottom.
Instead of live tank plants you can use bathing sponge mesh puff. In 6-12 hours after you put flame tetra into the spawning tank, the female fish lays up to 500 small sticky eggs.
Once the spawning is over, you should remove the flame tetra from the spawning tank and decrease the water level up to 10 cm; add several drops of methylene blue solution and turn on slight water aeration.
At water temperature about 26 °C, in about a day larvae start to hatch from the eggs. The larvae are tiny, but rather active. At first, they lie on the tank bottom, on the second day they stick to the spawning tank walls; quite often close to the water surface. On the 4-5th day the larvae turn into juveniles and start to swim. Since then you can start to feed them.
Starter feed can be the following: cyclops nauplii, infusorian, egg yolk. If there is not enough food, the fish juveniles die quickly.
Juveniles are demanding in terms of oxygen content. Therefore, additional water aeration is required in case of a tank with small surface area.
Only in a week you can start feeding the flame tetra juveniles with brine shrimp nauplii, cyclops and powdered dry food. Further juveniles feeding is of no trouble.
Juveniles grow very quickly: they become 1 cm long just in 3 weeks. At this age the juveniles go through full metamorphosis and become small copies of the adult fish species.
As the flame tetra juveniles grow you should put them into larger tanks with filtration and aeration. To avoid cannibalism among the juveniles you should sort them according to their size.
Every day you should remove food leftovers and other organic waste from the tank as well as add some fresh water, but not more than 5% of the total water amount.
When the juveniles are 1 month old you can add plant components into their diet. Considering the fact, that tetras are prone to overeating you should limit feeding them with water-swellable food for aquarium fish.