Latin name

Acanthurus coeruleus

Other names

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

Identification

Although the body color of reef fish can vary from light to dark blue, the dorsal, anal and caudal fins are golden blue. In young specimens, the edges of the dorsal and anal fins and the rings around the eyes are purplish blue, blue, or blue-green. Their colors change during growth from yellow juvenile, yellow-tailed blue semi-adult, and blue adult phases. Acanthurus coeruleus exhibits biofluorescence , that is, when illuminated with blue or ultraviolet light, it re-emits it as green and looks different from when illuminated with white light. Biofluorescence can facilitate intraspecific communication and masking.

Distribution

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

Habitat

The Blue Tang prefers coastal grassy and rocky areas and shallow waters over coral reefs.

Size

The Blue Tang averages 5 to 10 inches in length and can grow up to 15 inches in length.

Life history and Behavior

At the fry stage, the abdominal, second dorsal and second anal spines of some fish become poisonous and cause painful sensations similar to a bee sting. This poisonous property is lost when they reach the juvenile stage. The Blue Tang forms schools which may include surgeon fish and doctor fish.

Food and feeding habits

The Blue Tang feeds exclusively on algae, mostly during the day.

Reproduction

The blue surgeon reaches sexual age between 9 and 12 months. It is very difficult to determine the differences between the male and the female. Spawning takes place in February or March in the evening.