A total of 29 genera of algae, 15 rhodophytes, 7 phaeophytes and 7 chlorophytes, as well as marine phanerogams, were found in the stomach contents of the reef fishes Acanthurus bahianus Castelnau, A. chirurgus (Bloch) and A. coeruleus Bloch and Schneider. The plants included genera which develop morphological or chemical defenses, and carne from adult fishes, whose simpatric coexistence is examined.