A striking and uncommon schooling tetra with a sleek silver body, bold dark lateral stripe, and vivid red tail accents. The Red Tail Penguin Tetra is a peaceful, active freshwater fish that does especially well in planted aquariums and community setups with other calm tankmates. Hobby sources consistently associate this form with the Rio Teles Pires in Brazil.
The Red Tail Penguin Tetra is a beautiful twist on the classic penguin tetra look, combining the familiar streamlined body and dark “penguin” stripe with eye-catching red coloration in the tail. This fish is still relatively uncommon in the hobby, which makes it a standout choice for aquarists looking for something a little different from the usual community tetra selection. It is best kept in a group so it can display its natural schooling behavior and feel secure in the aquarium.
Native trade references place this fish in the Rio Teles Pires region of Brazil, and most sellers list it simply as Thayeria sp. rather than under a fully settled species-level name. In aquariums, it is valued for its peaceful temperament, active midwater swimming, and excellent compatibility with other small, non-aggressive fish.
Why We Love It
Bright red tail highlights, elegant black lateral stripe, active schooling behavior, peaceful community temperament, and a rarer look than standard penguin tetras.
Care Level
Easy to moderate. These fish are considered hardy and adaptable once settled, but they look and behave best in a mature, stable aquarium with good water quality and a proper group size.
Recommended Tank Setup
Keep them in a group of at least 6, with open swimming space plus plants, wood, or other cover. A 15-gallon tank is commonly suggested as a minimum, though larger tanks are better for a full school. Slightly subdued lighting and a planted or natural-style layout help bring out their best color and confidence.
Water Parameters
Temperature: 73–82°F
pH: 6.5–7.2 preferred
Temperament: Peaceful
Adult size: around 2–2.5 inches
Diet: Omnivore / micropredator; accepts quality prepared, frozen, and small live foods.
Tankmates
Best with other peaceful tetras, rasboras, Corydoras, small Loricariids, dwarf cichlids, and other calm community fish. Avoid large, aggressive, or overly boisterous species.
Feeding
Offer a varied omnivorous diet of high-quality flakes, micro pellets, frozen foods such as daphnia or baby brine shrimp, and other small meaty foods to maintain color and condition.
PetZoneSD Listing Notes
Sold as unsexed. Best purchased in groups for health, confidence, and display. This is an ideal choice for planted aquariums and peaceful South American-style community tanks.
Also Known As / Common Names
Red Tail Penguin Tetra, Redtail Penguin Tetra, Red Fin Penguin Tetra, Redfin Penguin Tetra, Red-Tailed Penguin Tetra, Rio Teles Pires Penguin Tetra, Tele Pires Penguin Tetra, Teles Pires Red Tail Penguin Tetra. In the aquarium trade, this fish is most commonly sold under Thayeria sp., Thayeria sp. “Rio Teles Pires,” Thayeria sp. “Red Tail Teles Pires,” or Thayeria sp. “Redtail (Teles Pires),” reflecting that it is typically treated as an undescribed Thayeria from the Rio Teles Pires region rather than a firmly standardized species name.
Scientific / Latin Name
Thayeria sp.
Thayeria sp. “Rio Teles Pires”
Thayeria sp. “Red Tail Teles Pires”
Thayeria sp. “Redtail (Teles Pires)”
