Blue Tetra: A Comprehensive Care Guide on Tank info, Breeding, Feeding, Common Diseases, and More

Mimagoniates microlepis blue tetra

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Blue Tetra: A Comprehensive Care Guide on Tank info, Breeding, Feeding, Common Diseases, and More

The Blue Tetra (Mimagoniates microlepis) is a captivating and vibrant species that has captured the hearts of aquarium enthusiasts worldwide. Known for its stunning blue coloration, this small characin fish adds a touch of elegance to any aquatic setting. In this comprehensive guide, we will delve into the fascinating world of the Blue Tetra, exploring its scientific classification, tank requirements, behavior, and more. Whether you’re a beginner or an experienced aquarist, understanding the essentials of caring for Blue Tetras will enable you to create a thriving and visually appealing aquatic environment that showcases the mesmerizing beauty of these fish.

Scientific NameMimagoniates microlepis
ClassActinopterygii (Ray-finned fish)
Size1.2 to 1.6 inches (3 to 4 centimeters)
Difficulty ScoreBeginner to Intermediate
Minimum Tank Size10 to 20 gallons
Water Temperature75°F to 82°F (24°C to 28°C)
pH Level5.8 to 7.2
Water HardnessSoft to moderately hard (dH 5-15)
DietHigh-quality flake or pellet food, live and frozen foods, occasional vegetable matter
CompatibilityPeaceful, suitable for community tanks
Tank MatesOther Tetra species, small Rasboras, Dwarf Corydoras
Lifespan3 to 5 years
BehaviorPeaceful and active, schooling fish
Source: Wikipedia

Blue Tetra Appearance

Blue Tetra

Blue Tetras (Mimagoniates microlepis) are small, stunning fish that display vibrant blue hues. Their striking blue coloration is one of the key characteristics that make them a popular choice among aquarium enthusiasts. These fish have elongated bodies with a slightly forked tail fin. Here are some essential details about their appearance:

Body Shape and Size

Blue Tetras typically grow to an average size of 1.2 to 1.6 inches (3 to 4 centimeters), making them ideal for smaller aquarium setups. Their slender bodies are adorned with shimmering blue scales that extend from head to tail.


The striking blue coloration of Blue Tetras sets them apart from other tetra species. They feature a deep blue dorsal fin and a lighter blue or silver belly, creating a stunning contrast. In well-maintained aquariums with proper care, their colors can become even more vibrant.

Blue Tetra Origin

Blue Tetras are native to South America, primarily found in the Amazon River basin. Their natural habitat includes slow-moving tributaries and heavily vegetated areas. To mimic their origin in an aquarium, it’s essential to recreate these conditions as closely as possible.

Blue Tetra Lifespan

With proper care, Blue Tetras can live for approximately 3 to 5 years in captivity. Providing them with an optimal environment, a balanced diet, and suitable tank mates can contribute to their longevity.

Blue Tetra Behavior

Blue Tetras are known for their active and peaceful behavior. They thrive in schools of six or more, which helps reduce stress and encourages natural behaviors. These fish are not typically territorial, making them an excellent choice for community aquariums.

Blue Tetra Male vs. Female

Distinguishing between male and female Blue Tetras can be challenging. However, some subtle differences exist:

  • Males tend to be slightly smaller and more slender than females.
  • Females may have a rounder belly, especially when they are carrying eggs.

Blue Tetra Pregnant

Blue Tetras, like many other fish, do not get “pregnant” in the traditional sense. Instead, female Blue Tetras will develop a more rounded belly when carrying eggs. To encourage breeding, provide them with ample hiding spots and soft plants where they can deposit their eggs.

Blue Tetra Tank Size and Requirements

Maintaining the appropriate tank size and conditions is crucial for the well-being of Blue Tetras:

Tank SizeA 10 to 20-gallon tank is suitable for a small school of Blue Tetras.
TemperatureMaintain a stable temperature between 75°F to 82°F (24°C to 28°C).
FiltrationUse a quality filter to maintain water clarity and remove toxins.
SubstrateFine gravel or sand substrate mimics their natural habitat.
Plants and DecorProvide plenty of live plants and hiding spots.
LightingModerate lighting is sufficient; Blue Tetras prefer subdued lighting.
Water ParametersMaintain a pH level between 5.8 and 7.2 and soft to moderately hard water.

Creating the perfect habitat for your Blue Tetras is crucial to their well-being and overall health. In this section, we will explore the tank size and other essential requirements to ensure your Blue Tetras thrive in your aquarium.

Blue Tetra Tank Size

The right tank size for a blue tetra is 20+ gallons. Selecting an appropriate tank size is the foundation of providing a comfortable and safe environment for your Blue Tetras. These fish are relatively small, with an average size of 1.2 to 1.6 inches (3 to 4 centimeters). However, they are social creatures and thrive when kept in schools of six or more individuals. Therefore, it’s essential to choose a tank size that accommodates both their size and their social nature.

For a small school of Blue Tetras, a tank with a capacity of 10 to 20 gallons is suitable. This size provides ample swimming space while allowing for the creation of a vibrant and visually appealing aquatic landscape.

Water Temperature

Maintaining the correct water temperature is vital for the health and happiness of your Blue Tetras. These fish thrive in tropical conditions, so it’s essential to keep the water temperature within the range of 75°F to 82°F (24°C to 28°C). Maintaining a stable temperature within this range is crucial to prevent stress and potential health issues.

To achieve and maintain the desired temperature, consider using a reliable aquarium heater with a thermostat. This will help you ensure that the water temperature remains consistent and comfortable for your Blue Tetras.

Filtration System

A high-quality filtration system is essential to keep the water in your Blue Tetra aquarium clean and free from harmful toxins. A well-functioning filter helps maintain water clarity, removes waste, and provides aeration. It also contributes to the overall stability of the tank’s ecosystem.

When selecting a filter, opt for one that suits the size of your tank and provides adequate filtration capacity. Canister filters or hang-on-back filters are popular choices for smaller aquariums housing Blue Tetras. Regular maintenance, such as cleaning or replacing filter media, is essential to ensure optimal performance.


The substrate at the bottom of your Blue Tetra aquarium plays a role in replicating their natural habitat. Blue Tetras are found in slow-moving tributaries with sandy or fine gravel bottoms. Therefore, it’s a good idea to use fine gravel or sand as the substrate in your tank.

A sandy or fine gravel substrate not only mimics their natural environment but also provides a suitable substrate for live plants to anchor their roots. It also allows your Blue Tetras to forage for food more naturally, as they may pick at the substrate for small food particles.

Plants and Decor

Blue Tetras appreciate a well-decorated tank with plenty of hiding spots and areas to explore. To create an ideal environment, consider incorporating live plants and other decor elements:

  • Live Plants: Blue Tetras thrive in tanks with live plants. Species like Java Moss, Java Fern, and Amazon Sword plants are excellent choices. Live plants not only provide natural aesthetics but also contribute to water quality by absorbing nitrates and providing shelter for the fish.
  • Driftwood and Caves: Adding driftwood, caves, and other decorations gives your Blue Tetras places to hide and explore. These features mimic their natural habitat and reduce stress in the aquarium.


Blue Tetras do not require intense lighting, and in fact, they often prefer subdued lighting conditions. Providing moderate lighting in the aquarium is sufficient for their well-being. Consider using a timer to maintain a consistent light cycle, typically around 10-12 hours of light per day. This helps establish a natural day-night cycle for your fish.

of these stunning fish in your aquarium.

Blue Tetra Water Parameters

Ensuring the right water conditions is vital for the health of Blue Tetras. Here are the key parameters to monitor:

  • pH Level: Keep the pH level between 5.8 and 7.2, with slightly acidic water being preferred.
  • Temperature: Maintain a stable temperature between 75°F to 82°F (24°C to 28°C).
  • Water Hardness: Blue Tetras thrive in soft to moderately hard water with a dH range of 5-15.

Blue Tetra Tank Mates

When it comes to selecting tank mates for your Blue Tetras (Mimagoniates microlepis), it’s essential to choose species that share similar temperament, size, and water parameter requirements. One excellent option is to consider other tetras, as they often coexist harmoniously in community aquariums. Here’s a list of some tetra species that are compatible with Blue Tetras:

  1. Neon Tetra (Paracheirodon innesi): Known for their brilliant blue and red stripes, Neon Tetras make fantastic companions for Blue Tetras. Their peaceful nature and similar size create a visually striking and harmonious display.
  2. Cardinal Tetra (Paracheirodon axelrodi): With their vibrant blue and red hues, Cardinal Tetras are close relatives of Neons. They share the same compatibility traits, making them ideal tank mates for Blue Tetras.
  3. Black Skirt Tetra (Gymnocorymbus ternetzi): These tetras have distinctive black markings on their fins and body, creating a beautiful contrast to the Blue Tetras’ vibrant blue colors. They are generally peaceful and coexist well.
  4. Rummy Nose Tetra (Hemigrammus rhodostomus): Recognizable by their bright red head and nose, Rummy Nose Tetras add a splash of color to your tank while sharing the peaceful temperament of Blue Tetras.
  5. Ember Tetra (Hyphessobrycon amandae): These tiny tetras boast an eye-catching fiery orange hue. Despite their small size, Ember Tetras are peaceful and can cohabitate peacefully with Blue Tetras.
  6. Glowlight Tetra (Hemigrammus erythrozonus): Named for the shimmering horizontal stripe along their body, Glowlight Tetras are peaceful companions that create a visually appealing contrast in your aquarium.
  7. Lemon Tetra (Hyphessobrycon pulchripinnis): Lemon Tetras exhibit a soft, lemon-yellow coloration and share the Blue Tetras’ peaceful nature, making them compatible tank mates.
  8. Congo Tetra (Phenacogrammus interruptus): These larger tetras display stunning iridescent colors and are generally peaceful. While they are a bit larger than Blue Tetras, they can coexist in larger community tanks.
  9. Pristella Tetra (Pristella maxillaris): Pristella Tetras feature a striking black and white dorsal fin. They are compatible with Blue Tetras in community setups and add variety to the aquarium’s aesthetics.
  10. Buenos Aires Tetra (Hyphessobrycon anisitsi): Recognizable by their silvery body and red markings, Buenos Aires Tetras are moderately sized and usually peaceful when kept in groups.

When introducing any new fish to your aquarium, it’s essential to monitor their behavior initially. While tetras are generally peaceful, individual temperament may vary. Ensure your tank is appropriately sized, well-maintained, and adequately decorated with hiding spots and plants to reduce stress and encourage natural behaviors among your Blue Tetras and their tank mates.

Blue Tetra Common Possible Diseases

Like all fish, Blue Tetras can be susceptible to various diseases. To keep your Blue Tetras healthy, monitor their behavior and appearance for signs of illness. Common diseases include:

  1. Ich (White Spot Disease): Recognizable by the appearance of white cysts on the fish’s body and fins.
  2. Fin Rot: This disease causes the degradation of the fins and can lead to severe damage if left untreated.
  3. Columnaris: Also known as cottonmouth, it presents as white patches on the mouth, fins, and body.
  4. Internal Parasites: These are harder to detect but can cause weight loss and abnormal behavior.

Blue Tetra Food & Diet

A well-balanced diet is essential for the health and vibrancy of your Blue Tetras (Mimagoniates microlepis). Providing proper nutrition ensures that they thrive, display their stunning blue colors, and remain active in your aquarium. In this section, we will explore the various aspects of feeding and the dietary requirements of Blue Tetras.

High-Quality Flake or Pellet Food

The foundation of a Blue Tetra’s diet should consist of high-quality flake or pellet food specifically formulated for tropical fish. These foods are designed to meet the nutritional needs of small tetra species like Blue Tetras. Look for options that contain a variety of essential nutrients and vitamins.

Feeding your Blue Tetras a high-quality staple food ensures that they receive a balanced diet with the necessary proteins, fats, and carbohydrates. It’s convenient and easy to portion, making it a practical choice for everyday feeding.

Live and Frozen Foods

While flake or pellet food is the staple of their diet, Blue Tetras benefit from occasional live and frozen foods. These foods offer variety and additional nutrients that can enhance their overall health and coloration. Consider including the following in their diet:

1. Brine Shrimp: Live or frozen brine shrimp are a favorite treat for Blue Tetras. These tiny crustaceans are rich in protein and simulate the natural diet of many fish in the wild.

2. Daphnia: Daphnia, also known as water fleas, are another nutritious option. They are small and easy for Blue Tetras to consume. Daphnia provides essential proteins and fiber.

3. Bloodworms: Frozen bloodworms are a protein-rich food source that Blue Tetras find irresistible. They can be given as an occasional treat to add variety to their diet.

When offering live or frozen foods, it’s important to ensure that they are appropriately sized for your Blue Tetras. You can either purchase these foods from a reputable aquarium store or consider culturing your own live foods for a sustainable food source.

Vegetable Matter

Blue Tetras, like many other fish, benefit from occasional vegetable-based foods. These foods help balance their diet and provide essential nutrients. Consider feeding them:

  • Spirulina Flakes: Spirulina-based flakes or pellets are rich in plant-based proteins and can enhance the blue coloration of your Blue Tetras.
  • Blanched Vegetables: Offer blanched vegetables such as zucchini or spinach as a treat. These should be soft and easy for the fish to nibble on.

Feeding Frequency

Blue Tetras are active fish, and they have relatively small stomachs. Therefore, it’s important to feed them in moderation and avoid overfeeding. A general guideline is to feed them once or twice a day, offering only an amount of food that they can consume within a few minutes.

Observing their eating habits is crucial. If you notice that there is uneaten food left in the tank after feeding, reduce the portion size in the future to prevent water quality issues.

Special Considerations

While Blue Tetras are generally easy to feed, there are a few special considerations to keep in mind:

  • Fry Diet: If you are breeding Blue Tetras and have fry, they will require specialized fry food or infusoria during their early stages. As they grow, you can transition them to finely crushed flakes and baby brine shrimp.
  • Variety: To ensure that your Blue Tetras receive a well-rounded diet, vary their food offerings regularly. This helps prevent nutritional deficiencies and keeps them engaged with their food.
  • Water Quality: Proper feeding also involves maintaining water quality. Uneaten food can lead to water pollution, so it’s essential to remove any excess food after feeding to keep the aquarium clean.

Blue Tetra Behavior & Temperament

Blue Tetras are known for their peaceful and active behavior. They are best kept in groups of six or more to reduce stress and encourage their natural schooling behavior. They enjoy exploring the tank, especially if it has ample hiding spots and plants.

Blue Tetra Breeding

Breeding Blue Tetras (Mimagoniates microlepis) can be a rewarding and educational experience for aquarium enthusiasts. Watching these vibrant blue fish reproduce and raise their fry is not only exciting but also offers insights into their natural behaviors. In this comprehensive guide, we will delve deeper into the world of Blue Tetra breeding, covering essential aspects from courtship to fry care.

Preparing for Breeding

Before embarking on the breeding journey, it’s crucial to ensure that your Blue Tetras are in optimal condition. Here are the steps to prepare for breeding:

1. Tank Setup

Create a separate breeding tank, ideally 10 to 20 gallons in size, with water parameters that mimic their natural habitat (pH 5.8-7.2, temperature 80°F/28°C). This tank should be well-established with live plants, providing ample hiding spots for the fish and surfaces for egg deposition.

2. Pair Selection

Select a healthy male and female for breeding. It’s important to ensure that they are mature, well-fed, and free from any signs of illness. Blue Tetras exhibit minimal sexual dimorphism, so it can be challenging to distinguish between males and females. Look for subtle differences, such as the rounder belly of a female when she’s carrying eggs.

3. Condition the Breeding Pair

To increase the chances of successful breeding, condition the pair with a varied diet rich in protein. Live and frozen foods like brine shrimp, daphnia, and bloodworms are excellent choices. This diet will enhance their overall health and prepare them for the rigors of breeding.

Courtship and Spawning

Once your Blue Tetras are in prime condition, you can introduce them into the breeding tank. Courtship and spawning typically follow a specific pattern:

1. Courtship Displays

The male will begin to court the female by displaying vibrant colors and performing intricate dances. He may chase the female around the tank in an attempt to gain her attention. This courtship ritual can be visually stunning, with both fish showcasing their vivid blue colors.

2. Egg-Laying

During the peak of courtship, the female will lay adhesive eggs on the undersides of plant leaves or other surfaces within the tank. The male will fertilize these eggs by releasing sperm into the water, which the eggs absorb.

3. Egg Care

After egg-laying, it’s essential to separate the adults from the eggs to prevent them from consuming their own offspring. Remove the breeding pair and return them to their original tank. Ensure the breeding tank conditions remain stable.

Raising the Fry

Successfully hatching and raising Blue Tetra fry requires attentive care. Here’s what you need to know:

1. Egg Hatching

Blue Tetra eggs usually hatch within 24 to 36 hours, depending on temperature and water conditions. The newly hatched fry will initially remain attached to the substrate by their adhesive threads.

2. Infusoria Diet

For the first few days, the fry feed on microscopic organisms called infusoria, which naturally develop in a well-established aquarium. You can also provide specialized fry food or powdered fry diets to ensure they receive adequate nutrition.

3. Gradual Transition

As the fry grow, you can gradually introduce them to finely crushed flakes and baby brine shrimp. Ensure that the food particles are small enough to be consumed by the tiny fry.

4. Tank Maintenance

Maintain pristine water conditions in the breeding tank. Perform regular water changes to remove debris and maintain water quality. Be gentle during cleaning to avoid disturbing the delicate fry.

5. Growth and Development

Blue Tetra fry will go through several stages of development, gradually acquiring their vibrant blue coloration as they mature. It’s important to keep them well-fed and monitor their growth to ensure their health.

Blue Tetra Breeding Temperature

To stimulate breeding behavior, slightly increase the temperature to the upper end of their preferred range, around 80°F (28°C). Additionally, provide a well-balanced diet to condition the fish for breeding.

Blue Tetra Origins

Blue Tetras originate from South America, specifically the Amazon River basin. In their natural habitat, they inhabit slow-moving tributaries and areas with dense vegetation. Replicating these conditions in your aquarium will contribute to the well-being of your Blue Tetras.

In conclusion, Blue Tetras are captivating and relatively easy to care for, making them an excellent choice for both beginners and experienced aquarists. By following the guidelines for their appearance, origin, lifespan, behavior, tank requirements, water parameters, tank mates, and breeding, you can create a thriving aquatic environment for these stunning fish. Keep in mind that attentive care and a well-balanced diet are key to ensuringthe health and longevity of your Blue Tetras.

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Lee Johnson

Lee Johnson

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I love sharing my knowledge about all things aquarium related. I have been keeping aquariums for over 20 years and cannot imagine a life without an aquarium. 

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