Surgeonfish

[denise]

The 70+ species of Surgeonfish get their name from a very unique characteristic, they possess a spine located on each side of the base of their tail fin. These foldable spines are extremely sharp, and flattened down when not in use. When surgeonfish are provoked, they flip their tail and the spines pop up, similar to a surgeons scalpel, hence the common name.


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All surgeonfish are herbivorous and live in the shallow, clear water of coral reefs. Throughout the day they graze on algae and plant matter growing on the reef, and rest by night in small crevices in the reef. Surgeonfish live primarily in large schools or in pairs.

Their spawning behavior is very unusual, as it seems to be dependent on certain phases, as they only spawn during a full moon! Males change body color and congregate in large groups with the females, then they all swim towards the surface, releasing sperm and eggs. Surgeonfish eggs contain a tiny bubble of oil that causes them to rise to the surface, and hatch after only a day! Young surgeonfish are carnivorous but turn herbivorous as they grow older.



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Ocean Surgeonfish, Acanthurus chirurgus, West Palm Beach

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Ocean Surgeonfish, dark color variety, Looe Key

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Blue tang, Acanthurus coeruleus, foraging over a coral reef. Note the spine on tail fin.
Photo by James Garrin.

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Juvenile Blue Tang, Key Largo
Photo by Ben Riley