Discover the Secrets of Penguin Tetra: Everything You Need to Know

penguin tetra

The penguin tetra (Thayeria boehlkei) is a small and captivating freshwater fish native to the Amazon River basin in South America. It is named after its black and white coloration, resembling the distinctive tuxedo of a penguin. With its sleek body, transparent fins, and striking contrast, the penguin tetra adds a touch of elegance to any aquarium.

penguin tetra

Penguin Tetra Size

When it comes to size, the penguin tetra is relatively small compared to other aquarium fish. On average, adult penguin tetras grow to about 2 inches (5 centimeters) in length. Their petite size makes them an excellent choice for smaller aquarium setups and community tanks.

Penguin Tetra Tank Size

To provide a comfortable and thriving environment for them, it is important to consider the appropriate tank size. A minimum tank size of 20 gallons (75 liters) is recommended for a small school of penguin tetras. This size allows them ample swimming space and ensures the maintenance of water quality.

Penguin Tetra Lifespan

In the right conditions, penguin tetras can live for an average of 3 to 5 years. Providing a well-maintained aquarium with suitable water parameters, a balanced diet, and a stress-free environment can significantly contribute to their longevity. Regular water changes, proper filtration, and a varied diet will help keep them healthy and vibrant.

Penguin Tetra Tank Mates

  1. Neon Tetras – These vibrant and popular fish are peaceful and share similar water parameter requirements with penguin tetras. The combination of their colorful appearance creates a visually stunning display in your aquarium.
  2. Guppies – Guppies are known for their colorful and lively nature. They are active swimmers and make excellent companions for penguin tetras. Keep in mind that male guppies with long, flowing fins may be more vulnerable to fin nipping.
  3. Rasboras – Species like Harlequin Rasboras or Lambchop Rasboras are peaceful and active schooling fish that can coexist peacefully with penguin tetras. They add movement and diversity to your aquarium community.
  4. Corydoras Catfish – These bottom-dwelling catfish are not only peaceful but also serve as efficient tank cleaners. Corydoras catfish are known for their playful behavior and can be a fascinating addition to your tank.
  5. Swordtails – Swordtails are visually appealing and have a peaceful temperament, making them suitable tank mates for penguin tetras. They come in various colors and patterns, adding excitement to your aquarium.

Penguin Tetra: Male and Female Differences

Distinguishing between males and females can be challenging. However, there are a few subtle differences that can help identify their gender. Males tend to have a slimmer body and display brighter colors compared to females. Additionally, females may appear rounder when carrying eggs. Although breeding them in home aquariums can be challenging, observing their courtship behavior is a fascinating experience.

Penguin Tetra Aggression: Myth or Reality?

One of their key attributes is their peaceful temperament. They are not known for being aggressive and rarely engage in territorial disputes or fin-nipping. However, it’s important to note that individual fish behavior can vary, and there might be occasional instances of aggression within a group.

To minimize the likelihood of aggression, it is recommended to keep them in a school of at least six individuals. By providing them with a larger group, you create a more natural and harmonious environment that helps disperse any potential aggression among themselves.

penguin tetra

Are Penguin Tetras Fin Nippers?

Penguin tetras are generally not considered fin nippers. Their small mouths and peaceful nature make them unlikely to cause harm to other fish in the tank. However, as mentioned earlier, individual behavior can vary, and there might be isolated cases where a penguin tetra may nip at the fins of slower or long-finned tank mates.

To prevent any fin-nipping incidents, it is advisable to avoid housing them with long-finned or slow-moving species that may be more susceptible to fin damage. Choosing tank mates with similar activity levels and body shapes can help maintain a peaceful and stress-free environment for all the inhabitants of your aquarium.


The penguin tetra is a delightful and visually striking addition to any aquarium. Its small size, attractive coloration, and peaceful demeanor make it an ideal choice for both beginner and experienced fishkeepers. With proper care, a suitable tank environment, and compatible tank mates, these charming fish will thrive and provide endless enjoyment in your aquatic world.

Penguin Tetra: Male and Female Differences

  1. Body Shape: In general, males tend to have a slimmer and more streamlined body shape compared to females. Females, on the other hand, may appear slightly rounder, especially when they are carrying eggs.
  2. Coloration: The male often displays more vibrant and intense colors than the female. Their black-and-white color pattern may be more pronounced, with sharper contrast and brighter hues. Female tetras may have slightly duller coloration.
  3. Fins: While the differences in fin shape and size between males and females are not significant, males may have slightly longer and more elaborate fins, particularly their dorsal and anal fins. Females may have fins that are slightly shorter and more rounded.
  4. Behavior: During breeding periods, the male may exhibit more energetic and vigorous behavior. They may chase after females and perform courtship displays to attract their attention. Females, on the other hand, may become more reclusive and seek out hiding spots to deposit their eggs.


  1. Q: How often should I feed my penguin tetras? A: They should be fed small portions of high-quality fish food two to three times a day.
  2. Q: Can penguin tetras be kept in a planted aquarium? A: Yes, they can thrive in a planted aquarium. The presence of live plants provides them with additional hiding spots and creates a natural-looking environment.
  3. Q: Do penguin tetras require a heater in their tank? A: They are tropical fish and prefer water temperatures between 75°F and 80°F (24°C and 27°C). Therefore, a heater is recommended to maintain the appropriate temperature.
  4. Q: Can penguin tetras be kept with shrimp? A: They generally coexist peacefully with most shrimp species, such as cherry shrimp or Amano shrimp. However, larger and more aggressive shrimp may pose a risk to the tetras.
  5. Q: How can I encourage breeding behavior in penguin tetras? A: Providing ample hiding places, such as dense vegetation or spawning mops, and maintaining stable water conditions can stimulate their breeding behavior.

Recommended Reading: Possum Wrasse: A Guide to Size, Tank Requirements, Care, and Breeding

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