Appearance
The distinctive characteristic of the family is that they have scalpel-like modified scales, one or more on either side of the peduncle of the tail. The spines are dangerously sharp and may seriously injure anyone who carelessly handles such a fish. The dorsal, anal, and caudal fins are large, extending for most of the length of the body. Their mouths are small and have a single row of teeth adapted to grazing on algae.
Surgeonfishes sometimes feed as solitary individuals, but they often travel and feed in schools, which may be a mechanism for overwhelming the highly aggressive defense responses of small, territorial damselfishes that vigorously guard small patches of algae on coral reefs.
