ABSTRACT
Parrotfishes are a diverse group, with 100 species distributed across the world's tropical and subtropical oceans. There are very few endemic parrotfish species as most species have a wide geographical range. Unlike many other fish groups whose distributions and species richness are shaped by evolutionary history and habitat size, parrotfish species richness is nearly equally controlled on a global scale by sea temperature (SST), and isolation, as well as habitat size and evolutionary history. Over smaller spatial scales, the species richness, abundance and biomass of parrotfish is dependent on the regional species pool, island size, and fishing with further influence of reef type and within reef habitats. Importantly, there are major differences in parrotfish assemblages between the Atlantic and Indo-Pacific, with assemblages in the Atlantic dominated by browsing species, smaller individuals and higher abundances, but lower biomasses than the Indo-Pacific. Parrotfish are also frequently found in adjacent biotopes (mangroves, seagrass, algal beds) in the Atlantic, mainly as juveniles, whereas they are not abundant in these biotopes in the Indo-Pacific. Differences in the structure of parrotfish assemblages and their relationship to environmental variables at different scales, suggest the ecological role of parrotfish may vary across regions.
