Redtail Penguin Tetra (Thayeria sp. "Rio Teles Pires")

Species Description

The Redtail Penguin Tetra (Thayeria sp. "Rio Teles Pires") is a beautiful and uncommon South American tetra prized for its bold black lateral stripe and vibrant red tail. While it shares the characteristic "penguin" pattern that gives the group its common name, the brilliant red caudal fin sets this species apart from the more familiar Penguin Tetra found in the aquarium hobby.

Peaceful by nature and best appreciated in a school, the Redtail Penguin Tetra adds graceful movement and eye-catching contrast to planted aquariums and community tanks. Its active midwater swimming behavior and elegant appearance make it an excellent choice for aquarists looking for something both distinctive and easy to enjoy.

What We Love

• Brilliant red tail provides a unique twist on the classic Penguin Tetra pattern.
• Peaceful temperament makes it an excellent community aquarium fish.
• Most impressive when kept in schools, where natural schooling behavior shines.
• Active midwater swimmer that adds constant movement to the aquarium.
• Looks exceptional in planted aquariums and natural aquascapes.
• An uncommon species that stands out without being difficult to care for.

Quick Care Guide

Care Level: Easy to Moderate

Temperament: Peaceful

Diet: Omnivore (High-Quality Flake Foods, Nano Pellets, Frozen Foods, Live Foods)

Adult Size: Approximately 2–2.5 Inches

Minimum Tank Size: 20 Gallons for a School

Swimming Zone: Middle Water Column

Social Structure: Peaceful Schools Starting at 6 Fish; Larger Groups Preferred

Origin Options: Collected

Approximate Purchase Size: 1–1.5 Inches (assuming this matches your inventory)

Tank Parameters

Temperature: 74°–80°F (23°–27°C)

pH: 5.5–7.2

General Hardness (GH): 1–8 dGH (18–140 ppm)

Carbonate Hardness (KH): 0–4 dKH

Total Dissolved Solids (TDS): 30–150 ppm

Minimum Aquarium Size: 20 Gallons for a School

Social Structure: Peaceful Schools Starting at 6 Fish

Swimming Zone: Middle Water Column

Water Flow: Low to Moderate

Experience Level: Beginner to Intermediate