In the present study a comparison of the otolith morphology of two species of parrotfish, family Scaridae, collected from the Red Sea coast of Egypt, is conducted to identify the most appropriate taxonomic characters that separate these species. Ontogenetic changes in the otoliths of the two scarid fishes become evident. In the otoliths of Chlorurus sordidus, the following characters are comparable in small-sized adult fishes: otolith width, otolith depth, mesial surface shape, lateral surface shape, shape of sulcus acusticus, column, rostrum and size of rostrum. The otoliths of young adults (GI) C. sordidus differ from the adult ones in 14 out of the 22 characteristics studied. In the otoliths of Hipposcarus harid, the following characters are comparable in small and large fish: otolith width, otolith depth, mesial and lateral surface shapes, shape of sulcus acusticus, rostrum and size of rostrum.

Foraging activity of roving herbivorous reef fish (RHs) from families Acanthuridae (surgeonfish; three species) and Scaridae (parrotfish; five species), and its relationship to resource availability and interference competition, was studied in the largest South Atlantic Reef complex (Abrolhos Bank, eastern Brazil). Observations were undertaken at four sites differing in resource availability and competitors' abundance (i.e. RHs and territorial herbivores from genus Stegastes). Turf algae (TA) were selected by most species in most sites, while other food items were generally avoided. Surgeonfish had higher feeding rates than parrotfish, the former grazing more frequently on fleshy algae (FA) and the latter on crustose calcareous algae (CCA). Both surgeonfish and parrotfish interacted agonistically most frequently with damselfish, followed by confamilial interactions. Despite these consistent patterns, feeding rates, food selection and frequency of agonistic interactions differed significantly between sites for most species. Bite rates on CCA and FA were disproportionally higher in sites where such items were more available, leading to significant spatial variation in grazing selectivity (i.e. positive rather than negative selection of CCA and ‘lower avoidance’ of FA). Although agonistic interactions were more frequent at sites where herbivorous fish (both roving and territorial) were most abundant, there was no clear relationship between interference competition and foraging patterns. These results indicate that the scarcity of other food may induce RHs to consume the dominant resources. They also support the hypotheses that RHs are unable to clear large tracts of reef surface of FA once these have proliferated, and that territorial herbivores do not limit the access of RHs to particular resources.

A specimen of the Indo-Pacific parrotfish Scarus ghobban has been reported from the Mediterranean Sea. The fish, the second one from the Mediterranean, was speared off the shore of Beirut (Lebanon) in November 2004. Morphometric measurements and meristic traits are provided and the presence of the species in the Mediterranean since 1999 is discussed.

This study compared the frequency with which different parrotfish individuals—initial (IP) and terminal (TP)—of three species associate with cleaner and follower species at Fernando de Noronha Archipelago. Only TP individuals posed at bottom-based cleaning stations. IP individuals were followed more often by the Noronha wrasse (Thalassoma noronhanum) than TP parrotfish. When following parrotfish, the Noronha wrasse capitalized upon drifting particles and occasionally cleaned them ‘on the move’ when they momentarily interrupted their feeding. Probably IP individuals were followed more often by the Noronha wrasse because they forage more often than the TP and thus make more drifting particles available to the wrasse. Since the IP individuals were cleaned by T. noronhanum while foraging, they visit cleaning stations less often than TP individuals.