title: Long distance dispersal and vertical gene flow in the Caribbean brooding coral Porites astreoides.
abstract: To date, most assessments of coral connectivity have emphasized long-distance horizontal dispersal of propagules from one shallow reef to another. The extent of vertical connectivity, however, remains largely understudied. Here, we used newly-developed and existing DNA microsatellite loci for the brooding coral Porites astreoides to assess patterns of horizontal and vertical connectivity in 590 colonies collected from three depth zones (≤10 m, 15-20 m and ≥25 m) at sites in Florida, Bermuda and the U.S. Virgin Islands (USVI). We also tested whether maternal transmission of algal symbionts (Symbiodinium spp.) might limit effective vertical connectivity. Overall, shallow P. astreoides exhibited high gene flow between Florida and USVI, but limited gene flow between these locations and Bermuda. In contrast, there was significant genetic differentiation by depth in Florida (Upper Keys, Lower Keys and Dry Tortugas), but not in Bermuda or USVI, despite strong patterns of depth zonation in algal symbionts at two of these locations. Together, these findings suggest that P. astreoides is effective at dispersing both horizontally and vertically despite its brooding reproductive mode and maternal transmission of algal symbionts. In addition, these findings might help explain the ecological success reported for P. astreoides in the Caribbean in recent decades.
authors.affiliation: Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA.
authors.forename: Xaymara M
authors.initials: XM
authors.lastname: Serrano
authors.affiliation: Department of Biology, The Pennsylvania State University, 208 Mueller Laboratory, University Park, PA, 16802, USA.
authors.forename: Iliana B
authors.initials: IB
authors.lastname: Baums
authors.affiliation: Center for Marine and Environmental Studies, University of the Virgin Islands, #2 John Brewer's Bay, St. Thomas, USVI 00802-9990, USA.
authors.forename: Tyler B
authors.initials: TB
authors.lastname: Smith
authors.affiliation: Australian Institute of Marine Science, The UWA Oceans Institute, 35 Stirling Highway, Crawley, WA 6009, Australia.
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Jones
authors.affiliation: Georgia Institute of Technology, School of Biology, 310 Ferst Dr., Atlanta, GA 30332, USA.
authors.forename: Tonya L
authors.initials: TL
authors.lastname: Shearer
authors.affiliation: Division of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Baker
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000235:genetics*; D017691:Caribbean Region; D057894:Coral Reefs; D051456:Gene Flow; D005828:Genetics, Population; D005838:Genotype; D018895:Microsatellite Repeats / Q000235:genetics*