Bloodfin Tetra Care Guide

Bloodfin Tetra


The Bloodfin Tetra (Aphyocharax anisitsi) is a small freshwater fish species native to South America. It is a popular choice among aquarium enthusiasts due to its striking appearance and peaceful nature. The Bloodfin Tetra is known for its unique characteristic of having blood-red fins contrasting against its silver body, creating a visually captivating display in aquariums.

Unique Characteristics or Features

The most notable feature of the Bloodfin Tetra is its vibrant blood-red fins. These fins stand out against the shimmering silver body of the fish, creating a visually stunning display when kept in groups or schools. The contrasting colors make the Bloodfin Tetra an attractive addition to any aquarium setup.

In addition to its striking appearance, the Bloodfin Tetra exhibits schooling behavior. They feel most secure and comfortable when kept in groups of six or more individuals. When swimming together in a school, their synchronized movements create a mesmerizing sight.

The Bloodfin Tetra is also known for its peaceful temperament, making it suitable for community aquariums. It generally gets along well with other peaceful fish species, such as other tetras, rasboras, and small catfish. Their peaceful nature makes them a great choice for beginner aquarists or those looking to maintain a harmonious aquarium environment.

Overall, the Bloodfin Tetra’s unique feature of blood-red fins, combined with its peaceful nature and schooling behavior, makes it an attractive and engaging species to keep in home aquariums.

Summary Table

Common NameBloodfin Tetra
Scientific NameAphyocharax anisitsi
Origin / DistributionSouth America
SizeUp to 2 inches (5 cm)
Aquarium Size10 gallons (38 liters) or larger
Water ParametersTemperature: 72-82°F (22-28°C) pH: 6.0-7.5 Hardness: 5-12 dGH
Feeding FrequencyOnce or twice a day
TemperamentPeaceful, schooling
TankmatesPeaceful community fish, such as other tetras, rasboras, and small catfish
BreedingEgg scatterers, requiring soft, acidic water and fine-leaved plants for spawning
Lifespan3-5 years
Care LevelBeginner
Unique Features / AppearanceBlood-red fins and a silver body
Conservation StatusNot evaluated (NE)
Additional NotesBloodfin Tetras are active swimmers that appreciate a well-planted aquarium with open swimming spaces. They are a popular choice for community tanks due to their peaceful nature. The blood-red fins make them visually striking, especially when kept in a school. Providing them with a varied diet consisting of quality flakes, live or frozen foods will help maintain their vibrant coloration. It’s important to maintain good water quality and perform regular water changes to ensure their well-being.


  • Common Name: Bloodfin Tetra
  • Scientific Name: Aphyocharax anisitsi
  • Family: Characidae
  • Order: Characiformes

The Bloodfin Tetra belongs to the family Characidae, which is a diverse family of freshwater fish commonly found in South America. It falls under the order Characiformes, which encompasses various species of characins and other related fish.

The scientific name of the Bloodfin Tetra is Aphyocharax anisitsi. The genus name, Aphyocharax, refers to its affiliation with the broader group of tetras known for their similar body shapes and behaviors. The species name, anisitsi, is a specific epithet given in honor of the Hungarian fish collector Dr. Lajos Anisits, who contributed significantly to the knowledge of South American fish species.

Natural Habitat & Distribution

The Bloodfin Tetra (Aphyocharax anisitsi) is native to the freshwater habitats of South America. It is primarily found in the countries of Argentina, Brazil, Paraguay, and Uruguay. Within these regions, the Bloodfin Tetra can be found in various river systems and tributaries.

In the wild, the Bloodfin Tetra inhabits densely vegetated areas, including slow-moving rivers, streams, and flooded forest areas. These habitats are typically characterized by shaded areas with overhanging vegetation, submerged plants, and fallen branches. The presence of vegetation provides the fish with ample hiding places and areas for foraging.

The fish is well adapted to living in clear or slightly acidic water with moderate to low current. It is often found in areas with soft substrates, such as sandy or muddy bottoms. These natural habitats provide the Bloodfin Tetra with an environment that closely resembles its preferred conditions in captivity.

Overall, the Bloodfin Tetra thrives in freshwater environments that offer ample vegetation, moderate water flow, and suitable hiding spots. Understanding its natural habitat and distribution helps aquarists recreate a similar environment in captivity, promoting the fish’s well-being and natural behaviors.

Physical Appearance


The Bloodfin Tetra (Aphyocharax anisitsi) reaches an adult size of approximately 2 inches (5 cm) in length. They are relatively small fish, making them well-suited for community aquariums and smaller setups.

Coloration and Patterns

One of the most striking features of the Bloodfin Tetra is its vibrant coloration. The body of the fish has a silver hue, which provides an excellent contrast to its distinct blood-red fins. The fins are translucent and possess a striking crimson coloration that extends along the edges. This unique coloration is where the species derives its common name.

Body Shape and Fin Structures

The Bloodfin Tetra has a streamlined body shape, typical of most tetra species. Its body is laterally compressed, allowing for easy maneuverability and swift swimming. The dorsal fin, located on the back of the fish, is relatively short and extends from the midsection towards the caudal fin. The anal fin, located on the ventral side near the anus, is also relatively short. The caudal fin, or tail fin, is forked and helps the fish with precise movements and quick turns.

Sexual Dimorphism

There are subtle differences between males and females of the Bloodfin Tetra species. The males tend to have more elongated and slender bodies compared to females. Additionally, during the breeding season, males may develop a slightly more intense coloration and display more pronounced fin extensions. Females, on the other hand, may appear rounder in the abdominal region, particularly when carrying eggs.

While the sexual dimorphism in Bloodfin Tetras is not as pronounced as in some other species, keen observers can distinguish these subtle differences, especially during breeding periods.

Behavior & Temperament

General Behavior

The Bloodfin Tetra (Aphyocharax anisitsi) is known for its peaceful and social nature. It is generally a calm and non-aggressive fish, making it well-suited for community aquariums. Bloodfin Tetras are shoaling fish, meaning they thrive when kept in groups or schools of six or more individuals. Keeping them in larger numbers allows them to display their natural schooling behavior, which can be quite captivating to observe.

Social Interactions with Other Fish

Bloodfin Tetras are generally friendly and peaceful towards other fish species. They rarely exhibit aggression towards tankmates, making them an excellent choice for community aquariums. They tend to coexist peacefully with other small, peaceful fish that share similar water parameter requirements.

Within their own species, Bloodfin Tetras engage in social interactions and hierarchy establishment. However, this behavior is usually not aggressive or harmful. It is important to maintain a group of Bloodfin Tetras rather than keeping them as solitary individuals, as they feel more secure and exhibit more natural behaviors in the presence of their own kind.

Suitable Tankmates

Bloodfin Tetras can be successfully housed with a variety of peaceful fish species that prefer similar water conditions. Some suitable tankmates for Bloodfin Tetras include other tetra species like Neon Tetras, Ember Tetras, or Harlequin Rasboras. Small catfish species, such as Corydoras or Otocinclus, can also make compatible tankmates.

It’s important to avoid keeping Bloodfin Tetras with larger, aggressive fish or fin-nipping species that might harass or stress them. Aggressive or territorial fish can disrupt the peaceful nature of the Bloodfin Tetras and cause them unnecessary stress.

When selecting tankmates for Bloodfin Tetras, consider their peaceful temperament, compatibility in terms of water parameters, and the size of the aquarium to ensure a harmonious and stress-free environment for all inhabitants.

Aquarium Requirements

Minimum Tank Size

For a comfortable and healthy environment, it is recommended to provide a minimum tank size of 10 gallons (38 liters) for a group of Bloodfin Tetras. However, larger tanks are always beneficial, especially if you plan to keep a larger school or include other fish species in the aquarium.

Water Parameters

  • Temperature: Bloodfin Tetras thrive in water temperatures between 72-82°F (22-28°C).
  • pH Level: Ideally, maintain a slightly acidic to neutral pH range of 6.0-7.5.
  • Hardness: The water hardness should be in the range of 5-12 dGH.

It is crucial to regularly monitor and maintain stable water parameters by using a reliable aquarium thermometer and water testing kits.

Filtration and Aeration Needs

Providing proper filtration is essential for maintaining good water quality in the aquarium. A quality aquarium filter, such as a hang-on-back (HOB) or sponge filter, helps remove waste, toxins, and provides aeration by agitating the water surface. Bloodfin Tetras appreciate moderate water flow, so adjust the filter output accordingly to avoid excessive turbulence.

Substrate Preferences

Bloodfin Tetras do not have any specific substrate requirements. However, a fine-grained substrate, such as sand or small-sized gravel, is preferable. This type of substrate allows the fish to sift through it comfortably while foraging for food without risking injury to their delicate barbels.

Lighting Requirements

Bloodfin Tetras do not have any specific lighting requirements beyond providing a regular day-night cycle. A standard aquarium light fixture or LED light is sufficient for their needs.

Decorations and Hiding Places

Creating a well-decorated aquarium helps simulate the natural habitat of the Bloodfin Tetra and provides them with places to explore, hide, and feel secure. Incorporate live or artificial plants, driftwood, and rocks to create hiding spots and visual barriers. The presence of plants, such as fine-leaved species like Java moss or floating plants like Amazon frogbit, adds to their comfort and provides shaded areas.

Additionally, dimming the aquarium lights using floating plants or adjustable lighting can help reduce stress and mimic their natural habitat, as Bloodfin Tetras prefer slightly shaded areas.

Diet & Feeding

Type of Diet

Bloodfin Tetras are omnivorous fish, meaning they consume a combination of plant matter and small prey. In the wild, their diet consists of insects, small crustaceans, and algae. In the aquarium, they readily accept a wide range of commercially available fish foods.

A balanced diet for Bloodfin Tetras should include a mix of high-quality flake or pellet foods suitable for tropical fish. Additionally, supplement their diet with live or frozen foods such as brine shrimp, daphnia, bloodworms, or small insect larvae to provide essential nutrients.

Feeding Frequency

Bloodfin Tetras should be fed small amounts of food once or twice a day. It is essential to feed them an amount they can consume within a few minutes, as overfeeding can lead to water quality issues. Monitoring their feeding behavior will help determine the appropriate amount of food to provide.

Tips for Providing a Balanced and Varied Diet

To ensure a balanced and varied diet for Bloodfin Tetras, consider the following tips:

  1. High-Quality Flakes or Pellets: Offer a staple diet of high-quality flake or pellet foods specifically formulated for tropical fish. These foods are typically nutritionally balanced and provide essential vitamins and minerals.
  2. Live or Frozen Foods: Supplement their diet with live or frozen foods to mimic their natural diet. Rotate between options such as brine shrimp, daphnia, bloodworms, or small insect larvae to provide variety and additional nutrients.
  3. Vegetable Matter: Bloodfin Tetras appreciate some vegetable matter in their diet. You can offer blanched and finely chopped vegetables like spinach, zucchini, or peas as an occasional treat.
  4. Feed Small Portions: Provide small portions of food that the Tetras can consume within a few minutes. This helps prevent overfeeding and maintains good water quality in the aquarium.
  5. Observation and Adjustments: Observe the feeding behavior of the Tetras to ensure they are actively eating and not leaving excess food uneaten. Adjust the amount of food accordingly to avoid waste and keep the aquarium environment clean.

Tank Mates

When choosing tank mates for Bloodfin Tetras (Aphyocharax anisitsi), it’s important to consider species that share similar water parameter requirements and peaceful temperaments. Here are some recommendations for creating a harmonious community tank:

Compatible Species

  • Other Tetra Species: Bloodfin Tetras can coexist peacefully with other tetra species such as Neon Tetras, Ember Tetras, Black Skirt Tetras, or Glowlight Tetras. Keeping a variety of tetras can create a visually stunning and diverse display of colors.
  • Rasboras: Peaceful rasboras like Harlequin Rasboras or Chili Rasboras make good tank mates for Bloodfin Tetras. They share similar water parameter preferences and peaceful temperaments.
  • Small Catfish: Corydoras catfish, such as Corydoras pygmaeus or Corydoras habrosus, can be suitable tank mates. These bottom-dwelling catfish species are peaceful and help keep the substrate clean.

Incompatible or Potentially Problematic Species

  • Large or Aggressive Fish: Avoid housing Bloodfin Tetras with larger or aggressive fish species that may harass or prey on them. Cichlids, aggressive barbs, or larger predatory fish should be avoided to ensure the safety and well-being of the Tetras.
  • Fin-nipping Species: Some fin-nipping species, such as certain barbs or aggressive tetras, may nip at the fins of Bloodfin Tetras. This can cause stress and potential injury. It is best to avoid keeping them together to maintain the Tetras’ health and fin condition.

Recommendations for Creating a Harmonious Community Tank

  • Group Size: Bloodfin Tetras are schooling fish and feel most secure and comfortable when kept in a group of six or more individuals. A larger school helps to reduce stress and allows them to display natural schooling behavior.
  • Adequate Space: Provide enough space in the aquarium to accommodate all tank mates comfortably. Avoid overcrowding, as it can lead to aggression and territorial issues among the fish.
  • Monitoring Behavior: Regularly observe the behavior of all tank mates to ensure compatibility. Look out for signs of aggression, stress, or any bullying behavior. If any issues arise, be prepared to make necessary adjustments or provide additional hiding spots to alleviate stress.
  • Hiding Places: Incorporate ample hiding places and visual barriers in the aquarium. Use live or artificial plants, caves, or driftwood to provide hiding spots and create a sense of security for all inhabitants.
  • Regular Maintenance: Maintain good water quality through regular water changes and proper filtration. This helps to ensure the overall health and well-being of all tank mates.


Breeding Bloodfin Tetras (Aphyocharax anisitsi) can be an interesting and rewarding experience. Here’s some information on their breeding behavior, ideal breeding conditions, and caring for the fry (offspring):

Breeding Behavior

Bloodfin Tetras are egg-scattering breeders. During the breeding process, males will chase and display courtship behavior towards the females. The males may exhibit more intense coloration and develop longer fin extensions to attract females. Once the female is ready to spawn, she will release her eggs, and the male will fertilize them by releasing milt over them. This process may repeat multiple times, resulting in the scattering of eggs throughout the aquarium.

Ideal Breeding Conditions

Creating ideal breeding conditions can help encourage the Bloodfin Tetras to breed. Here are some key factors to consider:

  1. Separate Breeding Tank: To maximize the chances of successful breeding, it is recommended to set up a separate breeding tank. This tank should be equipped with suitable spawning substrates and ample vegetation for the eggs and fry to seek shelter.
  2. Soft and Acidic Water: Bloodfin Tetras prefer soft, slightly acidic water conditions for breeding. Consider adjusting the water parameters within the following range: pH 6.0-6.8, temperature around 77°F (25°C), and soft water with a hardness of 4-8 dGH.
  3. Spawning Substrate: Provide fine-leaved plants, such as Java moss or spawning mops, as suitable surfaces for the eggs to attach to. These plants or materials will offer protection and prevent the adult fish from consuming the eggs.
  4. Diet and Conditioning: Prior to breeding, ensure the male and female are well-conditioned and receiving a varied and nutritious diet. Offering live or frozen foods rich in protein, such as bloodworms or brine shrimp, can help prepare them for successful spawning.

Raising Fry and Specific Care Requirements

Once the eggs are laid and fertilized, it’s important to provide proper care for the fry. Here are some key considerations:

  1. Separation from Adult Fish: After spawning, the adult fish may eat the eggs or newly hatched fry. To protect the eggs and fry, it is advisable to transfer them to a separate rearing tank or use a breeding net to isolate them from adult fish.
  2. Infusoria and Small Foods: Initially, the fry will rely on their yolk sac for nourishment. As they begin to free-swim, provide them with infusoria or commercially available liquid fry food. As they grow, transition them to finely crushed flake food or powdered fry food.
  3. Water Quality and Feeding Frequency: Maintain excellent water quality in the rearing tank, performing regular water changes to prevent the buildup of harmful substances. Feed the fry small amounts of food multiple times a day to ensure they receive sufficient nutrition.
  4. Gradual Growth and Tank Upgrade: As the fry grow, it may be necessary to transfer them to a larger grow-out tank to accommodate their increasing size. Ensure proper filtration and monitor their growth and behavior.

Health & Disease

Ensuring the health of your Bloodfin Tetras (Aphyocharax anisitsi) is essential for their overall well-being. Here are some common diseases that may affect them, along with prevention and treatment strategies:

Common Diseases and Their Symptoms

  1. Ich (Ichthyophthirius multifiliis): Symptoms include white spots resembling grains of salt on the fish’s body and fins, increased scratching or flashing against objects, and possible lethargy and loss of appetite.
  2. Fin Rot: Fin rot manifests as fraying or deterioration of the fins. Affected fins may appear ragged, discolored, or show signs of rotting. In severe cases, the infection may extend to the fish’s body.
  3. Fungal Infections: Fungal infections often appear as cotton-like growth on the fish’s body or fins. Affected areas may be fuzzy or have a white or grayish appearance.
  4. Parasitic Infections: Parasitic infections can cause various symptoms, such as increased mucus production, visible parasites on the fish’s body, scratching or rubbing against objects, and rapid breathing.

Prevention and Treatment Strategies

  1. Quarantine New Fish: Before introducing new fish to the aquarium, quarantine them for a period of time to ensure they are healthy and free of diseases. This helps prevent the introduction of infections to your existing fish.
  2. Maintain Optimal Water Quality: Regularly test water parameters and maintain clean water conditions. Perform partial water changes to control ammonia, nitrite, and nitrate levels. Stable water conditions help keep fish stress-free and less susceptible to diseases.
  3. Provide a Balanced Diet: A well-balanced diet with high-quality foods helps boost the immune system of Bloodfin Tetras. Provide a varied diet that includes quality flakes, pellets, and occasional live or frozen foods.
  4. Avoid Overcrowding: Overcrowding can lead to stress, poor water quality, and increased disease susceptibility. Ensure adequate swimming space and maintain appropriate fish-to-tank ratio.
  5. Quarantine and Treat Diseased Fish: If you notice any signs of disease, promptly isolate the affected fish in a separate quarantine tank to prevent the spread of infection. Consult with a veterinarian or aquatic specialist to determine the appropriate treatment, which may include medications, salt baths, or other remedies.
  6. Practice Good Hygiene: Maintain good hygiene practices by properly cleaning and disinfecting aquarium equipment and accessories before introducing them into the aquarium. This helps prevent the introduction of pathogens.

Care Level

The Bloodfin Tetra (Aphyocharax anisitsi) is generally considered a fish with a beginner level of care. Here’s an overview of their care level and special considerations:

Difficulty of Care

Bloodfin Tetras are relatively hardy and adaptable fish, making them suitable for beginners in the hobby. They have straightforward care requirements and are generally tolerant of a wide range of water conditions. Their peaceful nature and compatibility with other peaceful fish species further contribute to their beginner-friendly care level.

Special Considerations or Requirements

While Bloodfin Tetras are beginner-friendly, there are a few special considerations to ensure their well-being:

  1. Schooling: Bloodfin Tetras are social fish that thrive when kept in groups of six or more individuals. It’s important to provide them with companions to exhibit their natural schooling behavior and reduce stress.
  2. Water Quality: Although they can tolerate a range of water conditions, maintaining good water quality is vital for the health of Bloodfin Tetras. Regular water testing, proper filtration, and routine water changes are necessary to keep ammonia, nitrite, and nitrate levels in check.
  3. Compatible Tankmates: Ensure compatibility when selecting tankmates for Bloodfin Tetras. Avoid housing them with aggressive or fin-nipping species that may harass or stress them. Choosing peaceful species with similar water requirements will help create a harmonious community tank.
  4. Hiding Places: Providing ample hiding places, such as plants, caves, or driftwood, creates a sense of security for Bloodfin Tetras. These hiding spots help alleviate stress and provide shelter when needed.
  5. Varied Diet: Offering a varied diet that includes high-quality flakes or pellets, as well as live or frozen foods, helps maintain the health and vibrant coloration of Bloodfin Tetras. A balanced diet ensures they receive the necessary nutrients for their overall well-being.

Conservation Status

The conservation status of the Bloodfin Tetra (Aphyocharax anisitsi) according to the IUCN Red List or other sources is not evaluated (NE). This means that there is currently insufficient data available to assess its population status and conservation needs.

As for legal restrictions on keeping the species in captivity, it is important to check with local regulations and authorities in your specific region or country. Some countries may have restrictions or regulations in place to protect native fish species or to regulate the import and trade of certain fish species. Therefore, it is advisable to consult local authorities or seek guidance from reputable aquarium stores or fishkeeping communities to ensure compliance with any applicable laws or regulations.

Additional Information & Fun Facts

Here are some interesting facts and additional information about the Bloodfin Tetra (Aphyocharax anisitsi):

  • The Bloodfin Tetra is known for its resilience and adaptability, which contributes to its popularity among aquarists of all levels of experience.
  • It is a highly active and energetic fish, constantly on the move and exploring its surroundings. The sight of a school of Bloodfin Tetras swimming together is captivating and adds liveliness to an aquarium.
  • Bloodfin Tetras are known to be jumpers, so it is important to provide a secure lid or cover on the aquarium to prevent them from leaping out.
  • They have a relatively short lifespan compared to some other fish species, with an average lifespan of 3 to 5 years in captivity. However, with proper care and a healthy environment, some individuals may live even longer.
  • In the wild, Bloodfin Tetras are part of the diet of larger predatory fish, birds, and other aquatic creatures. Their schooling behavior helps provide safety in numbers and increases their chances of survival.
  • Bloodfin Tetras are known to exhibit more vibrant coloration and active behavior when kept in a well-planted aquarium with ample swimming space.
  • They are known to be excellent jumpers, so it is advisable to provide a tight-fitting lid or cover on the aquarium to prevent any accidental escapes.
  • Bloodfin Tetras are known to be relatively peaceful and non-aggressive, making them suitable for community aquariums with other peaceful fish species.
  • In the aquarium trade, Bloodfin Tetras are popular due to their striking appearance, peaceful nature, and ease of care.

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