Temporal evolution of coral reef fishes: global patterns and disparity in isolated locations

Aim\ud Many coral reef regions have a history of isolation and extinction. Our aim was to test whether the disparate evolutionary and biogeographical histories of the world's coral reef regions have significantly impacted temporal patterns of speciation within regions. In essence, do assemblages in peripheral locations contain the youngest coral reef fish species?\ud \ud Location\ud Pan-tropical coral reef systems.\ud \ud Methods\ud Molecular data (mitochondrial 16S rRNA, 12S rRNA, CO1, cytochrome b; nuclear TMO-4C4, S7 intron 1) were assembled for genera with near-complete taxon sampling (minimum 70% nominal species) from four major coral reef fish families (Chaetodontidae, Labridae, Pomacanthidae and Serranidae). This was combined with fossil data to simultaneously infer the phylogeny and estimate species' divergence times. Species' distributions were quantified using IUCN maps and the ages of species with different biogeographical extents were compared. Model fitting was used to compare the distribution of species' ages across the whole phylogeny with age distributions of species restricted to the Red Sea and Hawaiian Islands. \ud \ud Results\ud Temporal patterns of coral reef fish divergence were similar among major marine realms and regions. However, notable differences were recorded between the Red Sea and Hawaiian Islands. Red Sea endemics have diverged consistently throughout the last 16 Myr, whereas endemic species colonized the Hawaiian Islands in two distinct waves (0–3 Ma and 8–12 Ma). Differences in the proportions of allopatric and sympatric sister-species between Red Sea and Hawaiian endemics were also detected.\ud \ud Main conclusions\ud Despite differing geological histories, marine realms and regions have all experienced comparable and relatively recent divergences of extant coral reef fish species. Differences in age distributions and spatial relationships of endemic species in the Red Sea and Hawaiian Islands suggest that markedly different processes have shaped patterns of diversification in these peripherally isolated locations