True penguin tetra

Thayeria obliqua

Also known as Short-striped penguin, Obliqua penguin

FreshwaterFish

True penguin tetra (Thayeria obliqua) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 73–82°F (23–28°C)
pH: 5.5–7.2
Adult size: 3 in (7.6 cm)
Minimum tank: 29 gal (110 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Easy
Breeding: No record
Rarity: Rare
Origin: Madeira and Guaporé basins, Brazil and Bolivia
Family: Characidae

Overview

This is an easy, hardy schooling tetra that swims with its tail held down at an angle, a natural posture and not a sign of illness. Keep it in a group of at least eight, where the whole school leans and drifts together, and give it open swimming room since it is an active fish. It sits in the middle of the tank, is peaceful, and mixes well in a standard community with other calm fish of similar size. Feed a varied diet of flake, small pellets, and frozen foods such as bloodworm and daphnia. Because it grows larger than most tetras and stays on the move, give it a tank of around 110 liters.

In the wild

Thayeria obliqua comes from the Madeira and Guapore river basins of Brazil and Bolivia, warm, slow to moderate forest waters stained with tannins. Keep it at 23 to 28 degrees Celsius with a pH of 5.5 to 7.2. Softer, gently acidic water suits it best, and a darker setup with driftwood, some plants, and open surface space brings out its colour and its steady, angled swimming.

Good to know

This characin of the family Characidae grows to about 7.6 centimeters and is the original penguin tetra, described in 1908 and the type species of its genus. It is told from the common penguin tetra, Thayeria boehlkei, by its black stripe, which starts around the middle of the body and fades out before the dorsal fin rather than running the full length from gill to tail. Captive breeding is not well documented.

Did you know

Almost every penguin tetra in shops is actually Thayeria boehlkei, a look-alike with a full-length stripe. This is the fish that carried the penguin name first, back in 1908, and it is now the rarer of the two in the trade.