Dentition damage in parrotfishes feeding on hard surfaces at Fernando de Noronha Archipelago, southwest Atlantic Ocean

Parrotfishes (Scaridae) are renowned for their beak-like dentition, which enables them to bite on coralline and rocky surfaces to feed on algae and detritus. These fishes dwell in a wide range of habitats, but most studies on parrotfish feeding behavior and ecology have been made on coral reef sites. We report on parrotfishes with damaged dentition at Fernando de Noronha, a volcanic archipelago off the coast of northeast Brazil, in the tropical southwest Atlantic Ocean. We recorded tooth damage only in adult individuals (>40 cm total length [TL]) of 3 common species (Sparisoma amplum, S. axillare and S. frondosum) in the study area. The frequency of tooth damage varied among the species: 0.85% in S. amplum, 2.34% in S. axillare and 0.76% in S. frondosum. Two types of tooth damage were recorded: broken teeth and the whole dental plate protruding from the mouth. Individuals with damaged dentition were recorded at 6 out of 10 study sites. The abundance of parrotfishes with tooth damage and their presence at several sites within the archipelago indicate that this is a common and predictable event in the area. The reefs of Fernando de Noronha Archipelago comprise mostly basaltic rocks, which are much harder than the calcium carbonate matrix that generally composes coral reefs where most studies on parrotfish behavior and ecology have been conducted. This may explain the absence of reports of parrotfishes with damaged teeth in the scientific literature to date