Thayeria boehlkei
Holds an unusual head-up tilt at rest, with a black band running from gill plate to the lower lobe of the tail. The angle is distinctive in a planted tank and reads well against green backgrounds. Tougher than most tetras.
Penguin Tetra (Thayeria boehlkei) reaches 5–6 cm as an adult and needs a minimum tank of 90 L. Native to Amazon basin, it lives in the mid to top water column with a peaceful temperament. Aim for 22–28 °C, pH 5.8–7.5, and 2–15 dGH hardness. Lifespan is 4–6 years with good care. Keep penguin tetra in groups of 8+, yes schoolers need numbers to display natural behaviour. Diet: omnivore, Flake, micro pellets, frozen and live small foods. Plant-safe: Yes. Shrimp-safe: Yes (with adults).
Care at a glance
Holds an unusual head-up tilt at rest, with a black band running from gill plate to the lower lobe of the tail. The angle is distinctive in a planted tank and reads well against green backgrounds. Tougher than most tetras.
By Mike ElmiraUpdated 1 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether penguin tetra fits in your tank.
Mid to top
Yes
Group of 8+
Characidae
Omnivore
Flake, micro pellets, frozen and live small foods.
4–6 yrs
Medium
Amazon basin
Amazon basin
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Penguin Tetra (Thayeria boehlkei) needs a minimum tank of 90 L. They live in the mid to top water column and should be kept in groups of 8+, so a longer footprint matters more than depth.
Target 22–28 °C, pH 5.8–7.5, and 2–15 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Yes (with adults). Plant safety: Yes.
Penguin Tetra are omnivore. Flake, micro pellets, frozen and live small foods.
On Fin & Stem's 1–5 difficulty scale this species rates 1/5. Almost unkillable, a solid first-tank choice. Breeding difficulty: medium.
Typical lifespan in a well-maintained tank is 4–6 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
