Penguin Tetra

About the Penguin Tetra

The Penguin Tetra is a distinctive and elegant South American schooling fish, instantly recognised by the bold black stripe that runs from its nose through the body and into the lower lobe of its tail, creating the appearance of a penguin in profile. Native to the Amazon River Basin in Brazil and Peru, this peaceful species is well known for its unique swimming style, often holding its body at a slight upward angle.

Growing to around 5–6 cm, Penguin Tetras are active, hardy, and make an excellent addition to planted aquariums and freshwater community tanks. Their shimmering silver body, accented with a subtle golden sheen and striking black stripe, stands out beautifully against green plants, driftwood, and dark substrates.

Penguin Tetras thrive in mature aquariums with dense planting around the edges, open swimming space, and gentle water movement. They are highly social fish and should always be kept in schools of at least 8–10, where they display their natural schooling behaviour and become far more confident. They make excellent companions for Cardinal Tetras, Rummy Nose Tetras, Corydoras, Angelfish, Rams, Gouramis, Hatchetfish, and other peaceful South American community fish.

A varied diet of premium tropical flakes, micro pellets, frozen bloodworms, baby brine shrimp, daphnia, mosquito larvae, and other quality live or frozen foods will maintain their vibrant colours and excellent health.

Peaceful, active, and full of personality, the Penguin Tetra is a fantastic choice for both beginner and experienced aquarists looking to create a lively community aquarium.

Quick Care Guide

Scientific Name

Thayeria boehlkei

Common Name

Penguin Tetra

Origin

Amazon Basin (Brazil and Peru)

Adult Size

5–6 cm

Temperament

Peaceful

Diet

Omnivore

Minimum Tank Size

75 Litres

Temperature

23–28°C

pH

6.0–7.5

Water Hardness

2–12 dGH

Difficulty

Beginner

Lifespan

5–7 Years

Suitable For

Planted aquariums, Amazon biotopes, and peaceful community tanks

Frequently Asked Questions

How many Penguin Tetras should I keep?

Penguin Tetras are schooling fish and should always be kept in groups of at least 8–10. Larger schools create a more natural display and help the fish feel secure.

Why do Penguin Tetras swim at an angle?

This is completely normal. Penguin Tetras naturally swim with their heads slightly raised, giving them their distinctive posture.

What do Penguin Tetras eat?

They thrive on premium tropical flakes, micro pellets, frozen bloodworms, baby brine shrimp, daphnia, cyclops, mosquito larvae, and other live or frozen foods.

Can Penguin Tetras live with Angelfish?

Yes. Penguin Tetras make excellent companions for Angelfish in spacious aquariums, especially when the tetras are fully grown before being introduced.

Can Penguin Tetras live with shrimp?

Yes. Adult Cherry Shrimp and Amano Shrimp are generally safe, although very small shrimplets may occasionally be eaten.

Common Mistakes

Keeping them in small schools

Penguin Tetras become shy and less active when kept in groups smaller than eight.

Bright aquariums with little cover

Dense planting, driftwood, and floating plants help them feel secure and display their best colours.

Poor water quality

Regular water changes, stable water conditions, and efficient filtration are essential for long-term health.

Feeding only dry foods

A varied diet that includes frozen and live foods enhances colouration, immune health, and natural behaviour.

Housing them with aggressive fish

Choose peaceful community species that won't intimidate or harass these elegant schooling fish.