Blue Tang

Organisms / Vertebrates / Fish

Acanthurus coeruleus

Looe Key National Marine Sanctuary,  (24.545N, 81.407W)

March 21 & 22, 2006 (in the morning)

Photograph by Brent Sherwin

 

Descriptive Information

Field Marks: The juvenile Blue Tang is yellow and has greenish fins with a blue tip around the outside of each. The mature Blue Tang is purple-blue, and in sunlight its body shimmers. At the base of the tail fin is a yellow diamond-shaped mark. On the outside of each fin is a darker blue line. The Blue Tang has a blue eye with a gold ring around the pupil. Its body is flat and has a round profile. Its eyes are high on the head and the mouth is puckered. The Blue Tang has very poisonous flesh. At the base of the tail, on either side, there are yellow spines that can cause painful wounds.
Size: 7-12 inches (18-31 cm).
General Habitat: Coral reefs (we didn’t see them lower then 15 feet).
Range: Florida, Bermuda, and the Gulf of Mexico to Brazil.

Field Observations
The Blue Tang is one of the three types of surgeonfish found in Florida. It has the most distinct in coloration of the three species. We went snorkeling on two days during the trip, and each day we saw an immense amount of Blue Tang. After observing the Blue Tang on several occasions we concluded that this type of fish usually travels in groups of 5-100. It was especially interesting to see their feeding habits in a large group. They swam around in a large mass and then suddenly they would descend onto the coral with a furry, each one jockeying for the best spot. We observed them do this many times. Another interesting thing that we noticed was how the amount of light on their bodies changed their color completely. In the shadows they appeared black, but once they moved into the sunlight their true color appeared.

References
Alden, Peter, Richard B. Cech, Amy Leventer, Gil Nelson, and Wendy B. Zomlefer. National Audubon Society Field Guide to Florida. New York: Alfred A. Knopf, 1998.

Robins, C. Richard, and G. Carleton Ray. Peterson Field Guides Atlantic Coast Fishes. Boston: Houghton Mifflin Company, 1986.

Additional Photographs
Swimming in School
Video: Blue Tang

Page developed by Brent Sherwin and Kim Paulien