title: Restriction to large-scale gene flow vs. regional panmixia among cold seep Escarpia spp. (Polychaeta, Siboglinidae).
abstract: The history of colonization and dispersal in fauna distributed among deep-sea chemosynthetic ecosystems remains enigmatic and poorly understood because of an inability to mark and track individuals. A combination of molecular, morphological and environmental data improves understanding of spatial and temporal scales at which panmixia, disruption of gene flow or even speciation may occur. Vestimentiferan tubeworms of the genus Escarpia are important components of deep -sea cold seep ecosystems, as they provide long-term habitat for many other taxa. Three species of Escarpia, Escarpia spicata [Gulf of California (GoC)], Escarpia laminata [Gulf of Mexico (GoM)] and Escarpia southwardae (West African Cold Seeps), have been described based on morphology, but are not discriminated through the use of mitochondrial markers (cytochrome oxidase subunit 1; large ribosomal subunit rDNA, 16S; cytochrome b). Here, we also sequenced the exon-primed intron-crossing Haemoglobin subunit B2 intron and genotyped 28 microsatellites to (i) determine the level of genetic differentiation, if any, among the three geographically separated entities and (ii) identify possible population structure at the regional scale within the GoM and West Africa. Results at the global scale support the occurrence of three genetically distinct groups. At the regional scale among eight sampling sites of E. laminata (n = 129) and among three sampling sites of E. southwardae (n = 80), no population structure was detected. These findings suggest that despite the patchiness and isolation of seep habitats, connectivity is high on regional scales.
authors.affiliation: Department of Biology, The Pennsylvania State University, 208 Erwin W. Mueller Laboratory, University Park, PA, 16802, USA.
authors.forename: Dominique A
authors.initials: DA
authors.lastname: Cowart
authors.affiliation: Department of Biology, The Pennsylvania State University, 208 Erwin W. Mueller Laboratory, University Park, PA, 16802, USA.
authors.forename: Chunya
authors.initials: C
authors.lastname: Huang
authors.affiliation: Département des Ressources physiques et Ecosystèmes de Fond de mer (REM), IFREMER (Institut Français de Recherche pour l'Exploitation de la MER), Unité Environnement Profond-DEEP du, B.P. 70 - 29280, Plouzané, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Arnaud-Haond
authors.affiliation: Department of Biology, Hood College, 401 Rosemont Avenue, Frederick, MD, 21701, USA.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Carney
authors.affiliation: Department of Biology, The Pennsylvania State University, 208 Erwin W. Mueller Laboratory, University Park, PA, 16802, USA.
authors.forename: Charles R
authors.initials: CR
authors.lastname: Fisher
authors.affiliation: Department of Biology, The Pennsylvania State University, 208 Erwin W. Mueller Laboratory, University Park, PA, 16802, USA.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Schaeffer
mesh_terms: D000354:Africa, Western; D000818:Animals; D002140:California; D003080:Cold Temperature; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D051456:Gene Flow; D060851:Gulf of America; D007438:Introns / Q000235:genetics; D018895:Microsatellite Repeats / Q000235:genetics; D008969:Molecular Sequence Data; D009792:Oceans and Seas; D011077:Polychaeta / Q000145:classification* / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial
keywords: deep sea; hydrocarbon seep; microsatellite; population structure; siboglinid; vestimentiferan tubeworm