Résumé
With an area spanning half the world's tropical marine belt, from East Africa to western coast of Americas, the Indo-Pacific region is the largest biogeographic province. Within this province, coral reef species distributions varied greatly, with some species restricted to a single island while others are found throughout the province. In this context, the question related to the dynamic of spreading of species within such a large biogeographic province as always been a striking point. Recent phylogenetic studies on such topic remain too limited, and the results often conflicting to provide any consensus. In the perspective of providing a general view, it appears essential to compare the phylogeography of several taxa differing in life histories in order to reveal how geographic barriers may affect similarly evolutionary history of species. Here we investigate the phylogeographic patterns of seven coral reef fishes (i.e; Acanthurus triostegus, Dascyllus aruanus, Forcipiger flavissimus, Lutjanus kasmira, Paracirrhites forsteri, Zanclus cornutus and Rhinecanthus aculeatus) sampled among up to 29 locations throughout the Indo-Pacific with the objective of identifying common barriers to colonization and gene flow. Analyses based on sequences of the hypervariable region of the mitochondrial DNA Control Region (Dloop) revealed different phylogenetic patterns exhibited by the seven species. While some species showed marginal genetic isolation of remote islands, other showed clear phylogenetic signals. Nevertheless, all species did exhibit genetic footprint of exponential population growth. The pairwise mismatch distributions strongly differed among species revealing unique ancient demographic expansion signatures. The absence of common evolutionary histories is likely correlated with the high dispersal capabilities of coral reef fishes during their larval phase. Though recent works have emphasised local retention and small-scale self-recruitment at an ecological timescale, this does not prevent sporadic large-scale dispersal to spread molecular variants throughout the Indo-Pacific area on an evolutionary timescale. Financial support provided by: CRISP