Cardinal Tetra
The Cardinal Tetra (Paracheirodon axelrodi) is the larger and more brilliantly coloured cousin of the Neon Tetra.
Overview
The Cardinal Tetra (Paracheirodon axelrodi) is the larger and more brilliantly coloured cousin of the Neon Tetra. The species displays the same electric blue and red stripes - but the red extends the full length of the body rather than only the rear half. Cardinals are often considered the "prestige" version of Neons.
Natural History
Native to the upper Orinoco and Negro river basins of South America. Blackwater fish - soft, acidic, tannin-stained water.
Appearance
Adults 4-5 cm length (slightly larger than Neons). Brilliant blue dorsal stripe, full-length red lower stripe.
Temperament & Tankmates
Peaceful schooling. Groups of 6+ minimum, 10+ preferred.
Excellent community fish. Like Neons, avoid large predators.
Tank Size & Setup
Minimum: 75 L (20 gallon) for a school. Larger preferred.
Soft acidic water, gentle flow, planted, dim lighting, blackwater conditions ideal.
Water Parameters
- Temperature: 24-28°C.
- pH: 5.0-6.5 (acidic).
- Very soft water.
Diet
Same as Neon - micro pellets, flake, frozen and live small foods.
Health & Lifespan
5-10 years.
Common concerns same as Neon (less NTD risk in Cardinals).
Pros & Cons
Pros: more brilliant than Neons, slightly hardier, larger. Cons: soft acidic water preferred; less hardy than community staples.
Cardinal Tetra - frequently asked questions
Cardinal vs Neon - which?
Cardinals are more dramatic and longer-lived but require softer more acidic water. Neons are more available and adapt to harder water.
How long do they live?
5-10 years.
Beginner fish?
With cycled tank and soft water, yes.
🧠 Test yourself: guess the fish
Three clues from our quiz bank, each about another of our fish. Can you name them?
Clue 1.Nicknamed the 'king of the aquarium,' this round, flat Amazonian cichlid feeds its fry on mucus from its own skin.
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Clue 2.Domesticated from a dull carp over a thousand years ago in China, this orange fish is one of the oldest kept pets.
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Clue 3.Keepers love this diverse group for bold personalities but warn that many dig substrate and fiercely defend a chosen territory.
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