Red Tail Penguin Tetra (Thayeria boehlkei (red-tail form)) is a colourful red-tailed form of the familiar Penguin Tetra, with the same angled swimming style and peaceful schooling nature.
Appearance and natural habitat
In a settled group the fish spend much of their time together in midwater, with short displays and changes of position giving the aquarium constant movement. Keeping enough of their own kind improves confidence, colour and natural social behaviour.
In the wild, this fish comes from the upper Amazon region of South America. It is associated with vegetated wetlands and forest streams with shaded cover and open swimming areas. Matching some of that shelter and maintaining stable water helps the fish settle; use the species-appropriate conditions shown below.
Red Tail Penguin Tetra care
- Adult size: up to 6 cm
- Temperature: 22-28°C
- pH: 6.0-7.5
- Temperament: Peaceful community fish
- Group: At least 6; 10 or more is ideal
- Care level: Easy
Aquarium setup
Keep it in a mature planted aquarium with a dark background, open swimming space and a secure lid. It mixes well with calm community fish of a similar size.
Use an established filter and introduce the fish only after the aquarium is fully cycled. Regular partial water changes and steady conditions are safer than sudden attempts to adjust pH or hardness.
Feeding and tank mates
Feeding: Use a varied diet of fine flakes or micro pellets with frozen daphnia, brine shrimp and bloodworm.
Compatibility: A proper group helps the fish feel secure and display naturally. The red-tail name describes the colour form; general care follows Thayeria boehlkei.
Watch the group at feeding time to make sure every fish gets food, particularly when they share the aquarium with faster species. A varied diet, clean water and suitable companions are the best route to strong colour and long-term health.


Dan (verified owner) –
Lovely fish and arrived very healthy, so they fitted straight into my existing group. I would have like more at the time but I must have just got the last few of the stock you had. Very nice though.