Penguin Tetra

The Penguin Tetra (Thayeria boehlkei) is one of those fish that’s been around forever in the hobby—but still feels underrated when you actually keep them the right way.

At a glance, it’s simple: silver body, bold black stripe. But what makes them stand out is how they move. They swim at a slight angle, almost nose-up, and when a group gets going, it gives the tank a really distinct look that you don’t get with most other tetras.

They’re hardy, active, and easy to keep—but they really shine when you treat them like a proper schooling fish instead of just tossing a few into a community tank.

Natural Distribution & Habitat

Scientific name : Thayeria boehlkei comes from South America, mainly:

• The Amazon basin (Peru and surrounding areas)

Typical conditions:

• Soft, slightly acidic water
• Submerged wood and vegetation
• Tannin-stained water in many areas

They tend to hang in the upper to midwater, often near structure but still out in the open.

Size

They’re a bit larger than your average tetra.

• Adult size: around 2.5–3 inches

Big enough to be noticeable, but still very manageable.

Aquarium Care

These are very forgiving fish, but they look their best with the right setup.

• Tank size: 75 Liter minimum (30–40+ is better for a proper group)
• Aquascape: Plants and wood around the edges, open swimming space in the middle
• Substrate: Sand or fine gravel
• Lighting: Moderate

They’re not super picky, but they do best in tanks that aren’t overly bright or sterile.

👉 Give them some contrast (wood, plants), and they’ll look much better.