Cardinal Tetra

Cardinal Tetra (Paracheirodon axelrodi)

Appearance & Behavior

Bring brilliant blue and red to your freshwater aquarium with Cardinal Tetras. A shimmering blue stripe runs along each slender body above a vivid red band extending along most of its lower length, unlike the shorter red stripe of a Neon Tetra. A group moving through green plants creates a striking, colorful display. These peaceful, social fish feel more secure with their own kind and may become shy when kept alone or in very small groups.

Quick Care Guide

• Care Level: Moderate; best in a mature, established aquarium

• Temperament: Peaceful

• Adult Size: Approximately 1.5–2 inches

• Minimum Aquarium Size: 20 gallons recommended for a school

• Temperature: 75–82°F

• pH: 5.5–7.0

• Water Hardness: Soft water, generally below 10 dGH

• Diet: Omnivore

• Swimming Area: Middle

• Recommended Quantity: At least 6; preferably 10 or more when aquarium space and stocking allow

Aquarium Setup & Compatibility

Provide plants, shaded areas, gentle filtration, and open swimming space. Cardinal Tetras do best in a mature, fully cycled aquarium with stable water conditions and good oxygenation. They prefer warmer water than Neon Tetras, so choose tankmates with overlapping temperature requirements.

Good companions include small rasboras, peaceful tetras, and Corydoras species suited to the same warmer conditions. Avoid large, aggressive fish or any fish that could swallow them. Adult dwarf shrimp may coexist with cover, but shrimplets can be eaten.

Feeding

Feed Hatchery Diet 1.2 mm, supplemented with Daphnia and Bloodworms. Crush pellets or cut larger bloodworms into smaller pieces as needed to fit their small mouths. Offer small portions and ensure shy fish have a chance to eat.