Surgeonfishes and Unicornfishes in Hawaii
Surgeonfishes and unicornfishes are some of the most common reef fish in Hawaii. They usually have oval or oblong bodies and are often seen moving steadily over coral, rocks and reef slopes.
This group includes well-known fish such as yellow tangs, convict tangs, Achilles tangs, orangespine unicornfish and paletail unicornfish. In Hawaiian waters, 23 related species occur, and one is endemic.
Surgeonfishes and Tail Spines
Surgeonfishes get their name from the sharp spines near the base of the tail. These spines are often compared to scalpels because they can cut if the fish is handled. For snorkelers, they are not a problem as long as the fish are watched calmly and not touched.
Many surgeonfishes graze on algae. By feeding along rocks and reef surfaces, they help keep algae growth in balance and support healthier reef habitat.
Unicornfishes and Kala
Unicornfishes are related to surgeonfishes, but they have rigid bony keels instead of tail scalpels. Some species also develop a horn-like feature on the forehead. In Hawaiian, unicornfishes are called kala, meaning “thorn.”
Some unicornfishes feed on plankton in the water column, while surgeonfishes are often more closely tied to reef-surface grazing. Related pages include the Hawaii fish guide, parrotfishes, chubs, triggerfishes and Hawaii snorkeling tours.
