Penguin tetra tank mates
A 6 cm tetra with a bold black diagonal stripe and constant waggle swimming. Peaceful and hardy in a proper school.
Common mistakeBuying five penguin tetras for a crowded short tank is how the waggling school stresses everyone else. They need a proper group of six or more and lateral space for the swimming pattern that makes them interesting. Under-stocked or under-spaced, they look nervous and push calmer fish into the glass.
Each name below opens a pair check with Penguin tetra. That check is the decision, not the list itself.
Usually safer companions
Conservative shortlist from this profile. Open a pair page before you buy.
The Penguin tetra profile lists Boesemani Rainbowfish as both safe and a recommended pairing. Boesemani Rainbowfish schools in groups of 6 or more, so plan room for the whole group rather than one fish.
The Penguin tetra profile lists Congo Tetra as a recommended pairing. Congo Tetra schools in groups of 8 or more, so plan room for the whole group rather than one fish.
The Penguin tetra profile lists Dwarf Gourami as a recommended pairing. Dwarf Gourami is a peaceful beginner-care species with a 60L minimum. Run the pair checker for your specific tank before stocking.
The Penguin tetra profile lists Ember Tetra as a safe tank mate. Ember Tetra schools in groups of 8 or more, so plan room for the whole group rather than one fish.
The Penguin tetra profile lists Neon Tetra as a recommended pairing. Neon Tetra schools in groups of 6 or more, so plan room for the whole group rather than one fish.
The Penguin tetra profile lists Panda Corydoras as a safe tank mate. Panda Corydoras schools in groups of 6 or more, so plan room for the whole group rather than one fish. Panda Corydoras swims in the bottom zone while Penguin tetra stays in the middle, so the two will not crowd the same water column.
The Penguin tetra profile lists Rummy Nose Tetra as a safe tank mate. Rummy Nose Tetra schools in groups of 8 or more, so plan room for the whole group rather than one fish.
Risky or situational
May work with more water, a mature system, or a species-only setup. Read the pair page before you experiment.
Marked risky or situational on the profile. Tank length and group size change the outcome more than a temperament label does.
Pea Puffer is flagged predatory. Equal-size adults usually coexist, but the moment one is stressed, sick, or smaller after a moult, it becomes prey. Pea Puffer is rated semi-aggressive, so expect chasing, fin damage, or display behaviour directed at Penguin tetra. Run the pair checker before stocking.
Serpae Tetra is rated semi-aggressive, so expect chasing, fin damage, or display behaviour directed at Penguin tetra. Run the pair checker before stocking.
Tiger Barb is rated semi-aggressive, so expect chasing, fin damage, or display behaviour directed at Penguin tetra. Run the pair checker before stocking.
Yoyo Loach is rated semi-aggressive, so expect chasing, fin damage, or display behaviour directed at Penguin tetra. Run the pair checker before stocking.
Fish to avoid with Penguin tetra
Predation, aggression, or space rules on this profile. Treat these as poor default mixes.
African Cichlid reaches 15cm and is flagged predatory. Penguin tetra at 6cm is prey-sized for it. African Cichlid needs at least 200L, far above the 80L minimum for Penguin tetra. The tank that houses one stresses the other. African Cichlid is rated aggressive and Penguin tetra is rated peaceful. No community-style planning carries that gap.
Green Terror reaches 30cm and is flagged predatory. Penguin tetra at 6cm is prey-sized for it. Green Terror needs at least 300L, far above the 80L minimum for Penguin tetra. The tank that houses one stresses the other. Green Terror is rated aggressive and Penguin tetra is rated peaceful. No community-style planning carries that gap.
Jack Dempsey reaches 25cm and is flagged predatory. Penguin tetra at 6cm is prey-sized for it. Jack Dempsey needs at least 200L, far above the 80L minimum for Penguin tetra. The tank that houses one stresses the other. Jack Dempsey is rated aggressive and Penguin tetra is rated peaceful. No community-style planning carries that gap.
Oscar reaches 35cm and is flagged predatory. Penguin tetra at 6cm is prey-sized for it. Oscar needs at least 300L, far above the 80L minimum for Penguin tetra. The tank that houses one stresses the other. Oscar is rated aggressive and Penguin tetra is rated peaceful. No community-style planning carries that gap.
Tank size and groups
- Published minimum for Penguin tetra: 80L. Group minimum 6 (schooling).
- Compatibility changes when the tank is too short for turning, too little for a real school, or too warm for one species and not the other. That is why pair checks include tank context, not only temperament.
- Nearest litre hub to this minimum: 80L hub.
Plan before you buy
Start a pair check with Penguin tetra, or open a starter plan with the top safer companions in the builder.
Tank hubs: 80L
Related reading
Guides that list other fish with the same trait, so you can plan around the group rather than one row.
- Schooling & group fish →
Plan the group of 6+ before choosing tank mates.
- Beginner-friendly freshwater fish →
Penguin tetra is on this list. Hardier options for a first stock.
- Peaceful community fish →
Other peaceful species to shortlist beside Penguin tetra.
Filtration & heating
A 80L minimum tank for Penguin tetra needs a filter rated for at least 320L/hr turnover and a heater maintaining 22–28°C.
Similar fish (same category)
- Black phantom tetra · min 80L
- Columbian Tetra · min 80L
- Rosy Tetra · min 80L
- Rummy Nose Tetra · min 80L
- Splash tetra · min 80L
- Beckford Pencilfish · min 60L
- Black Neon Tetra · min 60L
- Bloodfin tetra · min 60L
Related (care + temperament)
Penguin tetra tank mates — quick answers
- What fish can live with Penguin tetra?
- Usually safer companions on this hub include Boesemani Rainbowfish, Congo Tetra, Dwarf Gourami, Ember Tetra, Neon Tetra, Panda Corydoras. Open each pair check before you buy — the list is a shortlist, not a guarantee.
- What tank mates should you avoid with Penguin tetra?
- Avoid African Cichlid, Green Terror, Jack Dempsey, Oscar based on size, temperament, or predation risk on this profile.
- What size tank do Penguin tetra need for a community?
- 80L is the planning floor for adult swimming space and bioload. A 98L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.