Feeding habits of the convict surgeonfish Acanthurus triostegus (Teleostei: Acanthuridae) in the Los Frailes reef, B.C.S., Mexico

Abstract

Studies of the feeding habits of reef-inhabiting herbivorous species are important since they are the first level in the trophic chain between primary producers and consumers. This study is the first contribution to determine the diet of the convict surgeonfish Acanthurus triostegus from the Los Frailes reef, Baja California Sur, Mexico. We describe qualitative and quantitatively the trophic spectrum of 50 A. triostegus individuals, using the traditional methods of frequency of occurrence and weight, as well as the index of relative importance. Overall, we identified 35 food components, of which 18 were algae of the Class Rhodophyceae, 10 of the Chlorophyceae and six Phaeophyceae. We determined that A. triostegus is a strict diurnal herbivore, which mainly feeds on the green alga Ulva linza, and even though it is a species with a wide geographic distribution, its behavioral feeding pattern is homogeneous.