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.
Lists below are built from this species record (safest, best with, risky, unsafe) — each link opens a pair-level check, not a guarantee.
Best tank mates (on file)
Merged from conservative safest and best with fields — de-duplicated by species.
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 Corydoras Catfish as a recommended pairing. Corydoras Catfish schools in groups of 6 or more, so plan room for the whole group rather than one fish. Corydoras Catfish 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 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
From risky tank mates and broad avoid with (excluding “unsafe” below). May work with species-only setups, more water, or mature systems — read the pair page.
Tiger Barb 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.
Yoyo Loach is rated semi-aggressive, so expect chasing, fin damage, or display behaviour directed at Penguin tetra. Run the pair checker before stocking.
Jack Dempsey reaches 25cm and is flagged predatory or as likely to eat small fish. Adult-size Penguin tetra at 6cm is inside that gape range. Jack Dempsey is rated aggressive, so expect chasing, fin damage, or display behaviour directed at Penguin tetra. Run the pair checker before stocking.
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.
Fish to avoid with Penguin tetra
From the unsafe list — predation, aggression, or space rules on this profile.
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.
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.
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
Pair checks for every mix, then multi-species stocking in the builder.
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