Candidate
Neon tetra
Paracheirodon innesi
Open full care profile →Photo identification · reviewed 2026-07-31
Neon tetra vs cardinal tetra
Use the red stripe, adult size and temperature preference to separate two frequently confused blue-striped tetras.
Candidate
Cardinal tetra
Paracheirodon axelrodi
Open full care profile →Interactive observation guide
Inspect one clue at a time
Use the photographs above, then select each clue. Do not make an identification from one feature alone.
A neon tetra's red stripe begins around the middle of the body; a cardinal's usually runs from eye to tail.
Care reality check
Compare the adult requirements
A visual identification changes which limits you should plan around.
| Requirement | Neon tetra | Cardinal tetra |
|---|---|---|
| Adult size | 3–4 cm | 4–5 cm |
| Minimum tank | 60 L · 60 cm | 75 L · 75 cm |
| Temperature | 20–26°C | 24–30°C |
| pH | 5–7.5 | 4.5–7 |
| GH | 1–10 dGH | 1–8 dGH |
| Social minimum | 8 | 8 |
| Temperament | peaceful | peaceful |
Visible differences
Clues to inspect
- A neon tetra's red stripe begins around the middle of the body; a cardinal's usually runs from eye to tail.
- Cardinals tend to look fuller-bodied and slightly larger as adults.
- Cardinals are usually kept warmer; a shop label should still be checked against the scientific name.
Shared traits
Why they are confused
- Both have an iridescent blue lateral stripe.
- Both are peaceful shoaling fish that should not be assessed from one isolated specimen.
Why it matters
Do not stop at the name
The distinction matters because their reviewed temperature, space and water ranges are not identical.
Uncertainty
When a photo is not enough
Stress, pale shop lighting and juvenile size can suppress colour. Do not decide from stripe brightness alone.