Gélin Pauline auteur aut IRD Fauvelot Cécile auteur aut IRD Bigot L. auteur aut IRD Baly Joseph auteur aut IRD Magalon H. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Here, we examined the genetic variability in the coral genus Pocillopora, in particular within the Primary Species Hypothesis PSH09, identified by Gelin, Postaire, Fauvelot and Magalon (2017) using species delimitation methods [also named Pocillopora eydouxi/meandrina complex sensu, Schmidt-Roach, Miller, Lundgren, & Andreakis (2014)] and which was found to split into three secondary species hypotheses (SSH09a, SSH09b, and SSH09c) according to assignment tests using multi-locus genotypes (13 microsatellites). From a large sampling (2,507 colonies) achieved in three marine provinces [Western Indian Ocean (WIO), Tropical Southwestern Pacific (TSP), and Southeast Polynesia (SEP)], genetic structuring analysis conducted with two clustering analyses (Structure and DAPC) using 13 microsatellites revealed that SSH09a was restricted to the WIO while SSH09b and SSH09c were almost exclusively in the TSP and SEP. More surprisingly, each SSH split into two to three genetically differentiated clusters, found in sympatry at the reef scale, leading to a pattern of nested hierarchical levels (PSH>SSH>cluster), each level hiding highly differentiated genetic groups. Thus, rather than structured populations within a single species, these three SSHs, and even the eight clusters, likely represent distinct genetic lineages engaged in a speciation process or real species. The issue is now to understand which hierarchical level (SSH, cluster, or even below) corresponds to the species one. Several hypotheses are discussed on the processes leading to this pattern of mixed clusters in sympatry, evoking formation of reproductive barriers, either by allopatric speciation or habitat selection. specialized Bayesian assignments cluster DAPC microsatellites Pocillopora scleractinian OCEAN INDIEN PACIFIQUE POLYNESIE ZONE TROPICALE 034 020 8 2 1411-1426 2018 2045-7758 https://www.documentation.ird.fr/hor/fdi:010072408 10.1002/ece3.3747 2045-7758 [F B010072408] https://www.documentation.ird.fr/hor/fdi:010072408 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers18-03/010072408.pdf IRD - Base Horizon / Pleins textes 2018-04-03 2023-07-11 fdi:010072408 fre