title: Long-distance dispersal via ocean currents connects Omani clownfish populations throughout entire species range.
abstract: Dispersal is a crucial ecological process, driving population dynamics and defining the structure and persistence of populations. Measuring demographic connectivity between discreet populations remains a long-standing challenge for most marine organisms because it involves tracking the movement of pelagic larvae. Recent studies demonstrate local connectivity of reef fish populations via the dispersal of planktonic larvae, while biogeography indicates some larvae must disperse 100-1000 s kilometres. To date, empirical measures of long-distance dispersal are lacking and the full scale of dispersal is unknown. Here we provide the first measure of long-distance dispersal in a coral reef fish, the Omani clownfish Amphiprion omanensis, throughout its entire species range. Using genetic assignment tests we demonstrate bidirectional exchange of first generation migrants, with subsequent social and reproductive integration, between two populations separated by over 400 km. Immigration was 5.4% and 0.7% in each region, suggesting a biased southward exchange, and matched predictions from a physically-coupled dispersal model. This rare opportunity to measure long-distance dispersal demonstrates connectivity of isolated marine populations over distances of 100 s of kilometres and provides a unique insight into the processes of biogeography, speciation and adaptation.
authors.affiliation: Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Simpson
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia.
authors.forename: Hugo B
authors.initials: HB
authors.lastname: Harrison
authors.affiliation: Department of Marine Science and Fisheries, Sultan Qaboos University, Al-Khod, Oman.
authors.forename: Michel R
authors.initials: MR
authors.lastname: Claereboudt
authors.affiliation: Le Centre de Biologie et d'Ecologie Tropicale et Méditerranéenne, l'Université de Perpignan, Perpignan, Pyrénées-Orientales, France; Laboratoire d'Excellence "CORAIL", Centre de Recherches Insulaires et Observatoire de l'Environnement, Moorea, French Polynesia.
authors.forename: Serge
authors.initials: S
authors.lastname: Planes
mesh_terms: D000818:Animals; D044822:Biodiversity; D057894:Coral Reefs; D017753:Ecosystem; D005399:Fishes / Q000145:classification / Q000235:genetics; D005828:Genetics, Population; D005843:Geography; D011157:Population Dynamics