The historical biogeography of coral reef fishes: global patterns of origination and dispersal

Abstract

Aim: To use recently published phylogenies of three major reef fish families to explore global patterns of species origin and dispersal over the past 65 million years. The key questions are: when and where did reef fishes arise, and how has this shaped current biodiversity patterns? Location: Biogeographic reconstructions were performed on globally distributed reef fish lineages. Patterns of lineage origination and dispersal were explored in five major biogeographic regions: the East P acific, the A tlantic, the I ndian O cean, the I ndo‐ A ustralian A rchipelago hotspot, and the C entral P acific. Methods: A dispersal, extinction and cladogenesis ( DEC ) model implemented in Lagrange was used to infer the most likely biogeographic scenarios at nodes on chronograms of three diverse reef fish families ( L abridae, P omacentridae, C haetodontidae). For the terminal branches ANOVA was used to compare patterns of origination on a regional and global scale. Patterns of origination and dispersal were examined within discrete time periods for the five biogeographic regions. Results: Temporal examination of hypothetical ancestral lineages reveal a pattern of increasing isolation of the East P acific and A tlantic regions from the E ocene, and the changing role of the I ndo‐ A ustralian A rchipelago from a location of accumulating ranges in the P alaeo/ E ocene, a centre of origination in the M iocene, to extensive expansion of lineages into adjacent regions from the P liocene to Recent. Main conclusions: While the East P acific and A tlantic have a history of isolation, the I ndo‐ A ustralian A rchipelago has a history of connectivity. It has sequentially and then simultaneously acted as a centre of accumulation ( P alaeocene/ E ocene onwards), survival ( E ocene/ O ligocene onwards), origin ( M iocene onwards), and export ( P liocene/Recent) for reef fishes. The model suggests that it was the proliferation and expansion of lineages in the I ndo‐ A ustralian A rchipelago (the C oral T riangle) during the M iocene that underpinned the current biodiversity in the I ndian and P acific O ceans.