title: Diet and diversification in the evolution of coral reef fishes.
abstract: The disparity in species richness among evolutionary lineages is one of the oldest and most intriguing issues in evolutionary biology. Although geographical factors have been traditionally thought to promote speciation, recent studies have underscored the importance of ecological interactions as one of the main drivers of diversification. Here, we test if differences in species richness of closely related lineages match predictions based on the concept of density-dependent diversification. As radiation progresses, ecological niche-space would become increasingly saturated, resulting in fewer opportunities for speciation. To assess this hypothesis, we tested whether reef fish niche shifts toward usage of low-quality food resources (i.e. relatively low energy/protein per unit mass), such as algae, detritus, sponges and corals are accompanied by rapid net diversification. Using available molecular information, we reconstructed phylogenies of four major reef fish clades (Acanthuroidei, Chaetodontidae, Labridae and Pomacentridae) to estimate the timing of radiations of their subclades. We found that the evolution of species-rich clades was associated with a switch to low quality food in three of the four clades analyzed, which is consistent with a density-dependent model of diversification. We suggest that ecological opportunity may play an important role in understanding the diversification of reef-fish lineages.
authors.affiliation: Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Fabio L
authors.initials: FL
authors.lastname: Lobato
authors.affiliation: Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia.
authors.forename: Diego R
authors.initials: DR
authors.lastname: Barneche
authors.affiliation: Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Alexandre C
authors.initials: AC
authors.lastname: Siqueira
authors.affiliation: Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Ana M R
authors.initials: AM
authors.lastname: Liedke
authors.affiliation: Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Alberto
authors.initials: A
authors.lastname: Lindner
authors.affiliation: Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, PR, Brazil.
authors.forename: Marcio R
authors.initials: MR
authors.lastname: Pie
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, and School of Marine and Tropical Biology, James Cook University, Townsville, QLD, Australia.
authors.forename: David R
authors.initials: DR
authors.lastname: Bellwood
authors.affiliation: Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Sergio R
authors.initials: SR
authors.lastname: Floeter
mesh_terms: D000818:Animals; D044822:Biodiversity; D057894:Coral Reefs; D004032:Diet; D019143:Evolution, Molecular; D005399:Fishes; D010802:Phylogeny