Blue Tang Identification Guide
How to identify the Blue Tang and tell the Pacific 'Dory' from the Atlantic species.
Read the full Blue Tang encyclopedia entry →
The name Blue Tang is used for two different reef fish, so identification starts with which ocean you are in.
Pacific Blue Tang (Paracanthurus hepatus)
- Royal-blue oval body with a bold black 'palette' marking along the upper side.
- Bright yellow tail and yellow accents on the fins.
- This is the famous 'Dory' of the Indo-Pacific.
Atlantic Blue Tang (Acanthurus coeruleus)
- Adults are uniformly powder-blue with fine wavy lines and no black palette.
- Juveniles are bright yellow, changing to blue with age.
Shared surgeonfish features
- Disc-shaped, compressed body and a small mouth for grazing algae.
- A scalpel-like spine at the base of the tail (hence 'surgeonfish').
Where you'll see one
Pacific Blue Tangs live on Indo-Pacific reefs; Atlantic Blue Tangs on Caribbean and western Atlantic reefs. The black palette mark plus yellow tail identifies the Pacific species, while a plain powder-blue body (or yellow juvenile) identifies the Atlantic one.
Frequently asked questions
Is the Blue Tang the same as Dory?
'Dory' is the Pacific Blue Tang (Paracanthurus hepatus), identified by its royal-blue body, black palette marking, and yellow tail.
Why are some Blue Tangs yellow?
Juvenile Atlantic Blue Tangs are bright yellow and gradually turn blue as they mature.