How does the Cardinal Tetra differ from the Neon Tetra?

The Cardinal Tetra has a continuous red stripe running the entire length of its lower body, grows slightly larger (up to 5 cm), and thrives in warmer temperatures (25–29 °C vs 20–25 °C).

Are Cardinal Tetras safe with Angelfish?

Yes—full-grown Cardinal Tetras introduced alongside juvenile angelfish in a planted tank are deep-bodied enough to coexist peacefully.

Cardinal Tetra

Paracheirodon axelrodi · family Characidae

Also: Red Neon Tetra, Paracheirodon axelrodi

Cardinal Tetra (Paracheirodon axelrodi) — aquarium fish — Wikimedia Commons / CC BY-SA

Temperature: 25–29 °C
pH: 5.5–7
Hardness: 2–8 °dGH
Tank volume: from 60 L
Maximum size: up to 5 cm
Group size: min 8, ideal 15
Temperament: Peaceful
Swimming zone: Middle
Difficulty: Beginner
Lifespan: 4–7 years

Description

The Cardinal Tetra (Paracheirodon axelrodi, 4–5 cm) is the crown jewel of planted and blackwater aquariums. Unlike the common Neon Tetra, its vivid crimson stripe runs the entire length of the lower body, it thrives in warm water (25–29 °C, including 28 °C tanks), and its fuller body size makes adult schools much safer with peaceful angelfish.

Care

Maintain a school of 8–15+ fish in a 60 L+ tank with warm, soft, slightly acidic water (25–29 °C, pH 5.5–7.0, GH 2–8), dark substrate, driftwood tannins, and dense plant cover.

Feeding

Omnivorous micro-predator: feed slow-sinking micro-pellets (0.5–0.8 mm), crushed flakes, and frozen baby brine shrimp, daphnia, or cyclops.

Compatibility

Compatibility data not yet available.

FAQ

How does the Cardinal Tetra differ from the Neon Tetra?: The Cardinal Tetra has a continuous red stripe running the entire length of its lower body, grows slightly larger (up to 5 cm), and thrives in warmer temperatures (25–29 °C vs 20–25 °C).
Are Cardinal Tetras safe with Angelfish?: Yes—full-grown Cardinal Tetras introduced alongside juvenile angelfish in a planted tank are deep-bodied enough to coexist peacefully.

AuthorGoldie Editorial

Goldie editorial team

Practising aquarists with a combined 30+ years of experience · Biologists and editors, fact-checking against FishBase and Seriously Fish · Every piece is reviewed by a qualified ichthyologist before publication

Goldie Science Board — collective scientific review panel

Reviewed byGoldie Science Board

Scientific board — ichthyologists and veterinarians

Ichthyologists and veterinarians with university degrees · Reference FishBase, Seriously Fish and peer-reviewed literature · Sign every reviewed article with their credentials shown

Sources

FishBase: Paracheirodon axelrodi · FishBase · 2026-05-22
Seriously Fish: Paracheirodon axelrodi · Seriously Fish · 2026-05-22