Cardinal Tetra Paracheirodon Axelrodi 2cm

Overview

The Cardinal Tetra is the classic blackwater shoaler, wearing an electric blue stripe above a band of deep red that runs the full length of the body. A tight shoal drifting through a dim, planted tank is the image many people start the hobby chasing. It comes from the Rio Negro and Orinoco systems and suits a soft water community.

• Adult Size: Around 3.5–4 cm (1.5 in); females slightly larger and rounder
• Lifespan: 4–5 years in the aquarium, far longer than in the wild

Origin

• Native to: Rio Negro and Orinoco basins: Brazil, Colombia, Venezuela
• Habitat: Slow forest streams, flooded forest; acidic tannin-stained water, leaf litter

Feeding

• Diet: Omnivorous
• Preferred Foods: Crushed flake, micro granules, bloodworm, daphnia, mosquito larvae, brine shrimp
• Feeding Habits: Small feeds once or twice daily; vary between dry and frozen

Tank Mates

• Best with: Small tetras, rasboras, Corydoras, Apistogramma, Otocinclus, small pencilfish
• Avoid: Angelfish and anything large enough to eat them

Aggression & Behaviour

• Temperament: Peaceful and timid
• Territoriality: None

Experience Level

• Difficulty: Beginner to Intermediate
• Challenges: Wild fish resent hard water and unstable, immature tanks

Water Parameters

• Water Type: Freshwater, soft and acidic
• Temperature: 24–28°C (75–82°F)
• pH: 5.0–7.0
• Hardness: 1–10 dGH
• Flow: Slow
• Tank Size: Minimum 60 litres for a shoal of ten or more

Final Notes

Add cardinals only to a mature tank; they are fragile in freshly set up or fluctuating conditions. Keep ten or more, as small groups hide and lose colour. Breeding is difficult and needs very soft, acidic water in near darkness, so most are wild caught or farm bred. Females are plumper than males. Given warm, soft water and gentle light, a cardinal shoal is hard to beat.