title: Recent origin and semi-permeable species boundaries in the scleractinian coral genus Stylophora from the Red Sea.
abstract: Reticulate evolution, introgressive hybridisation, and phenotypic plasticity have been documented in scleractinian corals and have challenged our ability to interpret speciation processes. Stylophora is a key model system in coral biology and physiology, but genetic analyses have revealed that cryptic lineages concealed by morphological stasis exist in the Stylophora pistillata species complex. The Red Sea represents a hotspot for Stylophora biodiversity with six morphospecies described, two of which are regionally endemic. We investigated Stylophora species boundaries from the Red Sea and the associated Symbiodinium by sequencing seven DNA loci. Stylophora morphospecies from the Red Sea were not resolved based on mitochondrial phylogenies and showed nuclear allele sharing. Low genetic differentiation, weak isolation, and strong gene flow were found among morphospecies although no signals of genetic recombination were evident among them. Stylophora mamillata harboured Symbiodinium clade C whereas the other two Stylophora morphospecies hosted either Symbiodinium clade A or C. These evolutionary patterns suggest that either gene exchange occurs through reticulate evolution or that multiple ecomorphs of a phenotypically plastic species occur in the Red Sea. The recent origin of the lineage leading to the Red Sea Stylophora may indicate an ongoing speciation driven by environmental changes and incomplete lineage sorting.
authors.affiliation: Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Roberto
authors.initials: R
authors.lastname: Arrigoni
authors.affiliation: Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, Milano 20126, Italy.|UMR ENTROPIE (IRD, Université de La Réunion, CNRS), Laboratoire d'Excellence-CORAIL, centre IRD de Nouméa, 101 Promenade Roger Laroque, BP A5, 98848 Noumea Cedex, New Caledonia.
authors.forename: Francesca
authors.initials: F
authors.lastname: Benzoni
authors.affiliation: Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Tullia I
authors.initials: TI
authors.lastname: Terraneo
authors.affiliation: UMR ENTROPIE (IRD, Université de La Réunion, CNRS), Laboratoire d'Excellence-CORAIL, centre IRD de Nouméa, 101 Promenade Roger Laroque, BP A5, 98848 Noumea Cedex, New Caledonia.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Caragnano
authors.affiliation: Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Berumen
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000502:physiology*; D044822:Biodiversity; D004247:DNA / Q000235:genetics*; D056426:Genetic Loci; D019156:Indian Ocean; D010802:Phylogeny
chemical_list: D004247:DNA