Blue Tang Blue Tang
Blue Tang

Blue Tang

Scientific Classification

Common Name
blue tang
Genus Species
Acanthurus coeruleus

Fast Facts

Blue to deep purple ovoid body with white or yellow spine along caudal peduncle. Intermediate form has a blue body and yellow caudal fin. Juvenile form has a yellow body with a light blue edging along the dorsal and anal fins. Dorsal fin is continuous from gill plate to caudal peduncle. Slightly centrally cleft (emarginate) caudal fin.
12 to 25 cm (5 to 10 in.) avg; 38 cm (15 in.) max
600.0 g (1.6 lbs.) avg
Marine plants and detritus
When breeding, blue tangs will congregate - forming spawning aggregations. Within these aggregations, they release gametes into the water column - introducing pelagic eggs. These eggs then incubate over the next several weeks to months following release.
Sexual Maturity
Male: 11 cm (4.3 in.)
Female: 13 cm (5.1 in.)
Western Atlantic: New York (seasonal) and Bermuda to Gulf of Mexico and Brazil
Eastern Atlantic: Ascension Island
2 to 40 meters (7 to 130 ft) in tropical & subtropical marine coastal waters
Global: Global population statistics are not currently available; however this fish species in not considered threatened or endangered.
Regional: In a ten year study conducted in the waters adjacent to the Virgin Islands, blue tangs were found to be more plentiful than any other fish species, accounting for an observed 15.4% of the region's overall fish population.
IUCN: Not listed
CITES: Not listed
USFWS: Not listed

Fun Facts

  1. The blue tang's scientific order, Perciformes, is the largest vertebrate order with 148 families containing roughly 9,300 species. 
  2. Blue tangs are capable of adjusting the intensity of their hue from light blue to deep purple. 
  3. Blue tangs are often found swimming in large schools cruising over the reef top, grazing on algae. These conglomerations are often composed of multiple species within the Acanthuridae (surgeonfish and tangs) family. 
  4. The blue tang possesses a sharp spine, or modified scale, located along either lateral edge of the caudal peduncle. These spines may be made to stand erect, providing the tang with an effective means of self-defense. 
  5. The flesh of the blue tang is poisonous. 
  6. For more information about bony fishes, explore the Bony Fishes InfoBook.  

Ecology and Conservation

Blue tangs primarily rely on marine algal species for sustenance. Algal resources available within the tang's habitat are often objects of high competition. Perhaps most notably, individual and/or paired damselfish prove to be extremely successful in their defense of an algal grazing territory. Blue tangs, however, are often find success in overwhelming these aggressively defended territories via the formation of large grazing aggregations. Recent alterations in algal communities throughout the Caribbean have had significant impacts on the populations of blue tangs. Movements of blue tangs are largely limited to single reef habitats, though they are wide-ranging over said reef. Accordingly, specific environmental impact over a particular reef site may exert extreme pressures over a local blue tang population.

Blue tangs are a popular saltwater aquarium specimen. They are commonly collected from the Caribbean basin for introduction into the commercial aquarium trade.


Bond, Carl E. Biology of Fishes - Second Edition. Saunders College Publishing, 1996.

Humann, Paul. Reef Fish Identification - Florida, Caribbean, Bahamas. New World Publications, Inc., 1992.