title: Genetic seascape of the threatened Caribbean elkhorn coral,Acropora palmata, on the Puerto Rico Shelf.
abstract: It has been proposed that the elkhorn coral,Acropora palmata, is genetically separated into two distinct provinces in the Caribbean, an Eastern and a Western population admixing in western Puerto Rico and around the Mona Passage. In this study, the genetic structure ofA. palmatasampled at 11 Puerto Rican localities and localities from Curaçao, the Bahamas and Guadeloupe were examined. Analyses using five microsatellite markers showed that 75% of sampled colonies had unique genotypes, the rest being clone mates. Genetic diversity among genets was high (HE= 0.761) and consistent across localities (0.685 to 0.844).FSTranged from -0.011 to 0.047 supporting low but significant genetic differentiation between localities within the previously reported Eastern and Western genetic provinces. Plots of genetic per geographic distances and significant Mantel tests supported isolation-by-distance (IBD) within Puerto Rico. Analysis with the softwareStructurefavored a scenario with weak differentiation between two populations, assigning eastern Puerto Rican locations (Fajardo and Culebra), Guadeloupe and Curaçao to the Caribbean Eastern population and western Puerto Rican locations (west of Vega Baja and Ponce), Mona and the Bahamas to the Caribbean Western population. Vieques and San Juan area harbored admixed profiles. StandardizedFSTs per 1,000 km unit further supported higher differentiation between localities belonging to differentStructurepopulations, with IBD being stronger within Puerto Rico than on larger regional scales. This stronger genetic transition seems to separate localities between putative Eastern and Western provinces in the eastern Puerto Rican region, not around the Mona Passage.
authors.affiliation: Department of Biology, University of Puerto Rico-Río Piedras, San Juan, Puerto Rico.
authors.forename: Pascal
authors.initials: P
authors.lastname: Mège
authors.affiliation: Department of Marine Sciences, University of Puerto Rico-Mayagüez, Call Box 9000, Mayagüez, Puerto Rico.
authors.forename: Nikolaos V
authors.initials: NV
authors.lastname: Schizas
authors.affiliation: Department of Marine Sciences, University of Puerto Rico-Mayagüez, Call Box 9000, Mayagüez, Puerto Rico.
authors.forename: Joselyd García
authors.initials: JG
authors.lastname: Reyes
authors.affiliation: Department of Biology, University of Puerto Rico-Río Piedras, San Juan, Puerto Rico ; Laboratório de Evolução e Genética Animal, Universidade Federal do Amazonas, Manaus, Brazil.
authors.forename: Tomas
authors.initials: T
authors.lastname: Hrbek