Penguin tetra

Thayeria boehlkei

Also known as blackline penguinfish

FreshwaterFish

Penguin tetra (Thayeria boehlkei) — Andrew Gray · CC BY-SA 3.0

Care at a glance

Temperature: 72–82°F; 22–28°C
pH: 6.0–7.5
Adult size: 2.6 in; 6.5 cm
Minimum tank: 20 gal; 75 L

Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Easy
Breeding: Medium
Rarity: Rare
Family: Characidae
Origin: Peru, Brazil

Overview

A peaceful schooling fish, so keep at least six and ideally more. They are active and spend most of their time in the middle and upper water. A tank of around 75 liters or more works, with temperatures in the low to high 20s C and a pH of 6 to 7.5. Feed flake, small pellets, and frozen foods like daphnia and bloodworms, and they mix well in a calm community.

In the wild

Penguin tetras live in slow tributaries and streams of the Amazon basin in Peru and Brazil, among leaf litter and submerged plants. The water there is soft and runs from slightly acidic to neutral. A tank with planting, some open swimming room, and gentle flow suits them, and a darker substrate shows their stripe off well.

Good to know

This fish belongs to the Characidae, the tetra family. It grows to roughly 6.5 cm and is named for the bold black stripe that runs back into the lower tail, giving it a penguin look. It is an egg scatterer with no parental care, and the eggs hatch in a day or two. The species is widespread and not considered at risk.

Did you know

Penguin tetras rest and swim at a head-up tilt rather than level. It looks odd at first, but it is normal for the species, not a sign of illness or a swim bladder problem.

Weekly picks

Tank mates

Penguin tetra is a peaceful, schooling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator