Blue Tang (Acanthurus coeruleus)

A member of the surgeonfish family that has distinctive coloration and is occasionally encountered by anglers, the blue tang is sometimes used as an aquarium fish and is also marketed fresh.

Identification

The oval, deep-bodied, and compressed blue tang is more circular than are other surgeonfish. Its coloring is almost entirely blue, ranging from powdery to deep purple, and it has many dark or light blue horizontal stripes running down the sides and blending into the background.

The dorsal and the anal fins have a bright blue border, and there is a white or yellow spine on the base of the tail. Juvenile blue tang are colored bright yellow, whereas intermediate fish have blue heads and bodies and yellow tails.


The yellow of the tail is the last to change to blue, and some fish are found with yellow tails. The change from juvenile to intermediate to adult coloration does not depend on size; some blue adults are smaller than yellow juveniles.

Size

Blue tang average 5 to 10 inches in length and may grow to 15 inches long.

Life history/Behavior

In the fry stage, the pelvic, the second dorsal, and the second anal spines of some fish are venomous and cause a painful sensation like a bee sting. This venomous quality is lost once they reach the juvenile stage. Blue tang form schools that may include surgeonfish and doctorfish.

Food and feeding habits

Blue tang feed entirely on algae, mostly during the day.

Other Names

blue tang surgeon; French: chirurgien bayolle; Portuguese: acaraúna-azul; Spanish: navajón azul.

Distribution

In the western Atlantic, the blue tang is most commonly found in Bermuda and from Florida to the Gulf of Mexico and Brazil. In the eastern Atlantic, it inhabits the waters off Ascension Island.

Habitat

Blue tang favor inshore grassy and rocky areas and shallows above coral reefs.