Tempo and mode of eco-morphological evolution in damselfishes (Pomacentridae)

Abstract

Coral reef fishes represent one of the most outstandingly diverse assemblages of vertebrates on the planet but our understanding of their mode of diversification remains limited. Here we test whether the damselfishes (Pomacentridae), one of the most species-rich families of reef-associated fishes, adaptively radiated during their evolutionary history. Tests of the tempo of lineage diversification using a time-calibrated phylogeny including 208 species did not support the expected pattern of rapid inital diversification that slowed through time as predicted by macroevolutionary theory. Evolutionary modeling of trophic traits similarly rejected the hypothesis of early among-lineage partitioning of ecologically relevant phenotypic diversity. Instead, damselfishes are shown to have experienced iterative convergent radiations wherein subclades converge on similar trophic strategies (i.e. pelagic feeders, benthic feeders, intermediate) and morphologies. We discuss that regionalization of coral reefs, bipartite life cycle of reef fishes, competition and functional constraints are good candidate of causal factors underlying the iterative ecological radiation and convergent evolution of damselfishes