title: Mitochondrial DNA Analyses Indicate High Diversity, Expansive Population Growth and High Genetic Connectivity of Vent Copepods (Dirivultidae) across Different Oceans.
abstract: Communities in spatially fragmented deep-sea hydrothermal vents rich in polymetallic sulfides could soon face major disturbance events due to deep-sea mineral mining, such that unraveling patterns of gene flow between hydrothermal vent populations will be an important step in the development of conservation policies. Indeed, the time required by deep-sea populations to recover following habitat perturbations depends both on the direction of gene flow and the number of migrants available for re-colonization after disturbance. In this study we compare nine dirivultid copepod species across various geological settings. We analyze partial nucleotide sequences of the mtCOI gene and use divergence estimates (FST) and haplotype networks to infer intraspecific population connectivity between vent sites. Furthermore, we evaluate contrasting scenarios of demographic population expansion/decline versus constant population size (using, for example, Tajima's D). Our results indicate high diversity, population expansion and high connectivity of all copepod populations in all oceans. For example, haplotype diversity values range from 0.89 to 1 and FST values range from 0.001 to 0.11 for Stygiopontius species from the Central Indian Ridge, Mid Atlantic Ridge, East Pacific Rise, and Eastern Lau Spreading Center. We suggest that great abundance and high site occupancy by these species favor high genetic diversity. Two scenarios both showed similarly high connectivity: fast spreading centers with little distance between vent fields and slow spreading centers with greater distance between fields. This unexpected result may be due to some distinct frequency of natural disturbance events, or to aspects of individual life histories that affect realized rates of dispersal. However, our statistical performance analyses showed that at least 100 genomic regions should be sequenced to ensure accurate estimates of migration rate. Our demography parameters demonstrate that dirivultid populations are generally large and continuously undergoing population growth. Benthic and pelagic species abundance data support these findings.
authors.affiliation: German Center for Marine Biodiversity Research (DZMB), Senckenberg am Meer, Wilhelmshaven, Germany.|Royal Netherlands Institute for Sea Research (NIOZ), Ocean Systems Sciences (OCS), 't Horntje, Texel, The Netherlands.
authors.forename: Sabine
authors.identifier: http://orcid.org/0000-0001-9322-9258
authors.initials: S
authors.lastname: Gollner
authors.affiliation: Senckenberg Natural History Collections Dresden, Museum of Zoology, Dresden, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Stuckas
authors.affiliation: German Center for Marine Biodiversity Research (DZMB), Senckenberg am Meer, Wilhelmshaven, Germany.
authors.forename: Terue C
authors.initials: TC
authors.lastname: Kihara
authors.affiliation: School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.|Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Laurent
authors.affiliation: German Center for Marine Biodiversity Research (DZMB), Senckenberg am Meer, Wilhelmshaven, Germany.
authors.forename: Sahar
authors.initials: S
authors.lastname: Kodami
authors.affiliation: German Center for Marine Biodiversity Research (DZMB), Senckenberg am Meer, Wilhelmshaven, Germany.
authors.forename: Pedro
authors.initials: P
authors.lastname: Martinez Arbizu
mesh_terms: D000818:Animals; D033342:Copepoda / Q000145:classification / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000235:genetics; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000235:genetics*; D009792:Oceans and Seas; D010802:Phylogeny; D011158:Population Growth; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV