rm
Passport
- Family
- Tetras
- Grows to
- 7.5 cm (3")
- Lives
- 5 years
- Temperament
- Peaceful
- Care
- Beginner
- Swims
- Mid-water
- Keep
- In a group of 6 or more
- Water
- 22–28 °C (72–82 °F)
PeruBrazil
Care requirements
i
On record for Penguin Tetra: adult size, lifespan, minimum tank, temperature, ph, hardness, minimum group, diet, care level, swim level, tank length.
A figure that is not on record is left out rather than guessed. One marked Suggested comes from keeping knowledge rather than a page.
- Minimum tank 70 L / 18.5 US gal
- pH 5.5–8
- Hardness 5–19 dGH
- Diet micropredator
- Tank length 60 cm minimum
Care notes written from general aquarium knowledge, not from the cited sources.
About
Penguins are named for the way they hold themselves. The fish rests at a distinct head-up angle rather than level, and the thick black stripe running down the flank carries on into the lower lobe of the tail — a marking no other common tetra has.
They get bigger than the shop label usually admits. Plenty of sources still quote a size that these fish pass comfortably, and a mature penguin is a substantial, chunky tetra rather than a small one. Plan the tank for the adult.
They come from the Araguaia in Brazil, which runs through everything from weedy wetland to jungle stream, and the species is correspondingly relaxed about where it ends up. Almost all trade stock is farm-bred and thoroughly adaptable.
Tank setup
Give your penguins length and open water. They're active, they cruise the middle and upper levels, and they use every bit of swimming room you provide.
Go dark underneath and add floating cover. The black stripe sharpens and the fish come forward under shade; under a bright lamp over pale gravel they hang back and look grey.
Furnish it with wood, twisted roots and a layer of dried leaves if you want the natural version. Their home water isn't especially planted, so a leaf litter arrangement is truer than a lush aquascape.
They're remarkably tolerant of water chemistry, happy from soft and acidic to hard and alkaline. Steadiness is what they want.
Feeding
Penguins are micropredators by nature and greedy opportunists in a tank. Anything you put in gets eaten, quickly.
Feed a mixture. Dried food as a base with regular bloodworm, daphnia and brine shrimp keeps the condition up and the stripe dark, and it gives them something to chase.
They're fast and assertive at feeding time. In a mixed tank, target-feed slower fish rather than assume the penguins will leave anything.
Avoid: feeding once a day in bulk. Spread it out and they're calmer for it.
Filtration and flow
Moderate to brisk flow suits them. Penguins are strong swimmers that hold position in a current happily, and they're one of the few small tetras that genuinely enjoy a bit of movement.
Filter for a fish larger than you might expect. They eat a lot and grow bigger than their reputation.
Water changes matter more than chemistry with this species. They'll adapt to whatever comes out of your tap and object to it being neglected.
With plants
Penguins are safe with plants and won't dig or graze.
Plant the sides and back and keep the middle clear. They need the open lane, and dense cover at the edges gives everything else in the tank somewhere to get away from a group of fast, boisterous fish.
Low-light plants suit the dim, tannin-stained setup they look best in — java fern, anubias, crypts and moss all work.
Health
They're hardy and long-lived, and there's little that's specific to them.
Their size and speed are the thing to watch, not their health. Penguins can bully smaller or slower tank mates simply by being everywhere first, and a shy fish going hungry in a tank with penguins is a common and easily missed problem.
They'll nip if kept in too small a group, like most tetras with a bit of size on them. A proper shoal keeps it among themselves.
Breeding
Penguins spawn readily and scatter their eggs among fine-leaved plants, giving no parental care and eating whatever they can find afterwards.
Condition the adults on live food, then move them to a dim tank floored with mesh or filled with moss. Soft, slightly acidic water and a small rise in temperature is the usual trigger.
Take the adults out once eggs are down. The fry are a reasonable size for a tetra and move onto baby brine shrimp fairly quickly after a first few days on infusoria, which makes them less demanding to raise than the smaller species.
Tank mates
Avoid8
- Least Killifish Penguin Tetra grows to 8 cm against Least Killifish at 2 cm, big enough to eat it.
- Scarlet Badis Penguin Tetra grows to 8 cm against Scarlet Badis at 2 cm, big enough to eat it.
- Common Goldfish Common Goldfish is not safe with Penguin Tetra: common goldfish and tetras are a bad pairing.
- Demasoni Cichlid Demasoni Cichlid is not safe with Penguin Tetra: african cichlids and tetras are a bad pairing.
- Electric Yellow Lab Penguin Tetra and Electric Yellow Lab do not mix: african cichlids and tetras are a bad pairing.
Only with care13
- Convict Cichlid Convict Cichlid is noticeably larger than Penguin Tetra and may bully it or outcompete it at feeding time.
- Jewel Cichlid Jewel Cichlid is noticeably larger than Penguin Tetra and may bully it or outcompete it at feeding time.
- Chinese Algae Eater Chinese Algae Eater is aggressive and Penguin Tetra is peaceful.
- Cherry Barb Penguin Tetra and Cherry Barb are an uneasy mix: barbs and tetras are a pairing to watch.
- Gold Barb Penguin Tetra and Gold Barb are an uneasy mix: barbs and tetras are a pairing to watch.
No conflict is recorded with the other 85 species in the database, so nothing to flag. 2 species are not covered at all, so they could not be judged either way.