Candidate
Rainbow shark
Epalzeorhynchos frenatum
Open full care profile →Photo identification · reviewed 2026-07-31
Rainbow shark vs red-tail shark
Check every fin, not just the tail: fin colour is the clearest distinction between these territorial cyprinids.
Candidate
Red tail shark
Epalzeorhynchos bicolor
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 rainbow shark normally carries red or orange across the dorsal, pelvic, anal and tail fins.
Care reality check
Compare the adult requirements
A visual identification changes which limits you should plan around.
| Requirement | Rainbow shark | Red tail shark |
|---|---|---|
| Adult size | 12–15 cm | 12–15 cm |
| Minimum tank | 150 L · 120 cm | 200 L · 120 cm |
| Temperature | 24–28°C | 23–27°C |
| pH | 6.5–8 | 6.5–8 |
| GH | 5–15 dGH | 5–15 dGH |
| Social minimum | 1 | 1 |
| Temperament | territorial | territorial |
Visible differences
Clues to inspect
- A rainbow shark normally carries red or orange across the dorsal, pelvic, anal and tail fins.
- A red-tail shark has a vivid red tail while the other fins remain dark.
- Young or stressed fish may show muted red, so examine fin placement rather than intensity.
Shared traits
Why they are confused
- Both have a dark torpedo-shaped body and an underslung grazing mouth.
- Both become territorial bottom-zone fish and are not schooling 'sharks'.
Why it matters
Do not stop at the name
The identity affects adult size and risk planning, though both require a long aquarium and one clear territory.
Uncertainty
When a photo is not enough
Poor condition can fade every fin. Do not use a single washed-out shop photo as a final diagnosis.