TY - JOUR
T1 - Population genetic structure of the tropical two-wing flyingfish (Exocoetus volitans)
AU - Lewallen, Eric A.
AU - Bohonak, Andrew J.
AU - Bonin, Carolina A.
AU - Van Wijnen, Andre J.
AU - Pitman, Robert L.
AU - Lovejoy, Nathan R.
N1 - Funding Information:
Funding for the study was provided by The Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant to NRL. We also acknowledge funding from the National Institute of Arthritis and Musculoskeletal and Skin Diseases (T32 AR56950 to EAL; R01 AR049069 to AJVW). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank all who assisted with the collection of specimens aboard research vessels: Endeavor (R McMunn, R Chase, B Collins, P Roussell, J Montminy, P Quigley, K Walsh, G Maltby, T Varney, A Wright, M Brennan, B Wilson, B Fanning, A Tucker, K Pohl, V Pascal, R Cooper, L Koren, H Hamner, R Lohmann), Shoyo Maru, Gordon Gunter, McArthur II, David Starr Jordan, Kahana, and Oscar Sette. In particular, we thank J Cotton, JC Salinas, and L Ballance for their ongoing dedication to flyingfish research and assistance with dipnet sampling logistics. Additional tissues were donated by the Marine Fisheries Service (B Collette). Specimen curation was assisted by the Royal Ontario Museum (R Winterbottom, E Holm, M Burridge, D Stacy, and F Pardo), Scripps Institution of Oceanography (P Hastings, HJ Walker, P Ajtai) and University of Toronto (M Huang, D Xiao, J Gordon, JC Szamosi). Genetic data collection was assisted by A Shah and B Shah. The scientific results and conclusions, as well as any views or opinions expressed herein, are those of the author(s) and do not necessarily reflect those of NOAA or the Department of Commerce.
Publisher Copyright:
© 2016, Public Library of Science. All rights reserved. This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
PY - 2016/10
Y1 - 2016/10
N2 - Delineating populations of pantropical marine fish is a difficult process, due to widespread geographic ranges and complex life history traits in most species. Exocoetus volitans, a species of two-winged flyingfish, is a good model for understanding large-scale patterns of epipelagic fish population structure because it has a circumtropical geographic range and completes its entire life cycle in the epipelagic zone. Buoyant pelagic eggs should dictate high local dispersal capacity in this species, although a brief larval phase, small body size, and short lifespan may limit the dispersal of individuals over large spatial scales. Based on these biological features, we hypothesized that E. volitans would exhibit statistically and biologically significant population structure defined by recognized oceanographic barriers. We tested this hypothesis by analyzing cytochrome b mtDNA sequence data (1106 bps) from specimens collected in the Pacific, Atlantic and Indian oceans (n = 266). AMOVA, Bayesian, and coalescent analytical approaches were used to assess and interpret population-level genetic variability. A parsimony-based haplotype network did not reveal population subdivision among ocean basins, but AMOVA revealed limited, statistically significant population structure between the Pacific and Atlantic Oceans (ΦST = 0.035, p<0.001). A spatially-unbiased Bayesian approach identified two circumtropical population clusters north and south of the Equator (ΦST = 0.026, p<0.001), a previously unknown dispersal barrier for an epipelagic fish. Bayesian demographic modeling suggested the effective population size of this species increased by at least an order of magnitude ∼150,000 years ago, to more than 1 billion individuals currently. Thus, high levels of genetic similarity observed in E. volitans can be explained by high rates of gene flow, a dramatic and recent population expansion, as well as extensive and consistent dispersal throughout the geographic range of the species.
AB - Delineating populations of pantropical marine fish is a difficult process, due to widespread geographic ranges and complex life history traits in most species. Exocoetus volitans, a species of two-winged flyingfish, is a good model for understanding large-scale patterns of epipelagic fish population structure because it has a circumtropical geographic range and completes its entire life cycle in the epipelagic zone. Buoyant pelagic eggs should dictate high local dispersal capacity in this species, although a brief larval phase, small body size, and short lifespan may limit the dispersal of individuals over large spatial scales. Based on these biological features, we hypothesized that E. volitans would exhibit statistically and biologically significant population structure defined by recognized oceanographic barriers. We tested this hypothesis by analyzing cytochrome b mtDNA sequence data (1106 bps) from specimens collected in the Pacific, Atlantic and Indian oceans (n = 266). AMOVA, Bayesian, and coalescent analytical approaches were used to assess and interpret population-level genetic variability. A parsimony-based haplotype network did not reveal population subdivision among ocean basins, but AMOVA revealed limited, statistically significant population structure between the Pacific and Atlantic Oceans (ΦST = 0.035, p<0.001). A spatially-unbiased Bayesian approach identified two circumtropical population clusters north and south of the Equator (ΦST = 0.026, p<0.001), a previously unknown dispersal barrier for an epipelagic fish. Bayesian demographic modeling suggested the effective population size of this species increased by at least an order of magnitude ∼150,000 years ago, to more than 1 billion individuals currently. Thus, high levels of genetic similarity observed in E. volitans can be explained by high rates of gene flow, a dramatic and recent population expansion, as well as extensive and consistent dispersal throughout the geographic range of the species.
UR - http://www.scopus.com/inward/record.url?scp=84991490781&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84991490781&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0163198
DO - 10.1371/journal.pone.0163198
M3 - Article
C2 - 27736863
AN - SCOPUS:84991490781
SN - 1932-6203
VL - 11
JO - PLoS One
JF - PLoS One
IS - 10
M1 - e0163198
ER -