Penguin tetras , scientifically known as Thayeria boehlkei , are also commonly called slant tetras due to their characteristic tilted swimming posture. They belong to the Characidae family and are native to South America, specifically the Amazon and Araguaia rivers between Brazil and Peru. Their natural habitat is calm, freshwater with abundant vegetation, providing them with a perfect environment to thrive.
Size and physical characteristics
Penguin Tetras are small fish, reaching up to 6 cm in length, although in some cases they can grow up to 8 cm , depending on their environment. Their bodies are elongated and slender, silvery- white with a distinctive black stripe that runs from the base of the caudal fin to the head, giving them an elegant and unique appearance compared to other tetras.
One of the most curious characteristics of this species is its swimming position, which is tilted. Instead of moving horizontally like most fish, Penguin Tetras swim with their heads slightly raised and their bodies at an oblique angle of between 20° and 25° , giving them a unique appearance.
Behavior and sociability
These fish are known for their peaceful and sociable nature . They prefer to live in groups, known as schools . They are not aggressive and make ideal companions for community aquariums, provided the other species share their calm temperament. If you are planning to include Penguin Tetras in your aquarium, keep in mind that it is recommended to have at least 6 to 7 specimens so they feel comfortable and secure working together as a group, since schooling fish tend to interact best with others of their own species.
Within schools, it has been observed that dominant individuals tend to occupy central positions, where they are more protected, while less dominant individuals are located at the edges. This group behavior is a natural mechanism of protection and internal organization.
Aquarium conditions
For penguin tetras to thrive in captivity, it's essential to replicate their natural habitat as closely as possible. Below are some key parameters:
- Aquarium size: The aquarium should have a minimum of 50 cm long (ideally better if you have a tank between 60-80 liters) so that they have enough space to swim as a group.
- Water temperature: These fish require water with a temperature between 22ºC and 28ºC.
- pH of water: Ideally, the pH should be maintained between 5.8 and 7.5, with a preference for slightly acidic or neutral waters.
- Water hardness: The water should be soft, preferably between 5 and 10 DH, without exceeding 20.
In addition, the aquarium should be well-planted with abundant vegetation, especially floating plants that filter the light, creating shaded areas that mimic their natural habitat. The ideal substrate is a dark, sandy one , and it's important to leave open spaces so they can swim freely.
Food
In their natural habitat, Penguin Tetras feed primarily on small insects and larvae. In captivity, it is important to provide them with a varied diet to keep them healthy and energetic. It is recommended to feed them high-quality commercial flake or pellet foods, preferably with a good vegetable content. It is also advisable to supplement their diet with live foods such as brine shrimp or mosquito larvae.
It's essential to remember that they tend to feed at the water's surface . Any remains that fall to the bottom should be properly removed to avoid water contamination, unless you have bottom-dwelling fish that will take care of the remains.
Reproduction
Breeding Penguin Tetras in an aquarium can be challenging, though not impossible. To do so, a separate aquarium of approximately 30 to 40 liters should be prepared . This aquarium should have plenty of plants and minimal lighting to reduce the risk of fungal growth on the eggs.
The reproduction process includes several steps:
- Place one male and two females in the breeding tank. The females will release their eggs between the plants.
- Once the eggs have been laid, the adults should be removed to prevent them from eating the eggs.
- In about 24 hours long., the eggs will hatch and the fry will begin to swim freely after 5 daysDuring this period, they should be fed with infusoria and brine shrimp nauplii.
The main difficulty is that they need very well-controlled water (with a pH between 6.0 and 7.0 ), and the eggs and fry are very sensitive to light. It is also important to prevent the parents from staying with the offspring for too long, as they could end up eating the eggs.
Common diseases
Like other aquarium fish, Penguin Tetras can be affected by various diseases if proper water conditions are not maintained. One of the most common ailments in this species is white spot disease, which often arises when there are sudden temperature changes or prolonged stress. They can also be affected by swim bladder infections, which can impair their ability to swim properly.
To prevent these diseases, it is essential to perform regular water changes and maintain an efficient filtration system that helps keep nitrite , ammonia, and nitrite levels under control.
Optimal aquarium maintenance , along with proper feeding and a favorable social environment, will ensure that your Penguin Tetras live happy and healthy lives, which in captivity can be between 4 and 5 years.
Penguin Tetras are an excellent choice for any aquarium enthusiast, thanks to their beauty, tranquility, and the possibility of living with different species, as long as their need to live in schools is respected and the appropriate conditions are maintained.