Population genomics of a sailing siphonophore reveals genetic structure in the open ocean
The open ocean is a vast, highly connected environment, and the organisms found there have been hypothesized to represent massive, well-mixed populations. Of these, the man-o'-war or bluebottle (Physalia) is uniquely suited to long-distance travel, using its gas-filled float and muscular crest to catch the wind and sail the sea surface. We tested the hypothesis of a global, panmictic Physalia population by sequencing whole genomes of 151 samples and found five distinct lineages, with multiple lines of evidence indicating strong reproductive isolation, despite range overlap. We then scored thousands of images of Physalia uploaded to the citizen-science website inaturalist.org and identified four recognizable morphologies, described their geographical distribution, and linked them to four of the lineages that were identified with genomic data. We conclude there are at least four species, three of which correspond to species proposed by scientists in the 18th and 19th centuries, along with one newly named species, Physalia minuta Church and Dunn, sp. nov. Within each species, we observe significant population structure, with evidence of persistent subpopulations at a regional scale. We used ocean circulation modeling to show that these subpopulations align with predominant currents and winds. Our findings indicate that, even in these sailing species, genetic variation is highly partitioned across the open ocean.
Authors
- Colin J. Anthony (ORCID: https://orcid.org/0000-0001-8100-6516)
- Amandine Schaeffer (ORCID: https://orcid.org/0000-0002-8320-4951)
- Kohei Oguchi (ORCID: https://orcid.org/0000-0001-7873-4723)
- Zachary Lewis (ORCID: https://orcid.org/0000-0003-0160-4722)
- Diane Le Gouvello (ORCID: https://orcid.org/0000-0002-2893-9410)
- Steven H. D. Haddock (ORCID: https://orcid.org/0000-0001-9420-4482)
- João M. Gonçalves (ORCID: https://orcid.org/0000-0001-7717-658X)
- Samuel H. Church (ORCID: https://orcid.org/0000-0002-8451-103X)
- Rebecca R. Helm (ORCID: https://orcid.org/0000-0002-5904-1267)
- Andrea L. Schmidt
- Thomas K. Doyle (ORCID: https://orcid.org/0000-0003-1616-5590)
- Moninya Roughan (ORCID: https://orcid.org/0000-0003-3825-7533)
- Álvaro González-Rajal (ORCID: https://orcid.org/0000-0002-9230-0339)
- Bruno I. M. M. Magalhães (ORCID: https://orcid.org/0000-0002-2885-1195)
- Carlos J. Moura (ORCID: https://orcid.org/0000-0002-6243-5988)
- Maciej K. Mańko (ORCID: https://orcid.org/0000-0001-6872-0256)
- Eric A. Lazo-Wasem (ORCID: https://orcid.org/0000-0001-5627-1852)
- Alex de Mendoza (ORCID: https://orcid.org/0000-0002-6441-6529)
- Chris Simon (ORCID: https://orcid.org/0000-0002-3576-1120)
- Mary Beth Decker (ORCID: https://orcid.org/0000-0003-0479-5309)
- Gaku Yamamoto
- Laura Prieto (ORCID: https://orcid.org/0000-0003-4704-7757)
- Catriona Munro (ORCID: https://orcid.org/0000-0002-0334-4541)
- Jessica N. Perelman (ORCID: https://orcid.org/0000-0003-3832-1750)
- Namrata Ahuja (ORCID: https://orcid.org/0000-0002-2282-9755)
- Alejandro Damian‐Serrano (ORCID: https://orcid.org/0000-0002-2544-0489)
- Casey W. Dunn (ORCID: https://orcid.org/0000-0003-0628-5150)
- Guillermo D’Elía (ORCID: https://orcid.org/0000-0001-7173-2709)
- David R. Burdick (ORCID: https://orcid.org/0000-0002-1716-4437)
- Tauana Cunha (ORCID: https://orcid.org/0000-0002-8493-2117)
- Reza Bergemann (ORCID: https://orcid.org/0000-0003-4829-4733)
- Javier Sellanes (ORCID: https://orcid.org/0000-0002-6942-0762)
- Kylie Anne Pitt (ORCID: https://orcid.org/0000-0002-2292-2052)
- Ronel Nel (ORCID: https://orcid.org/0000-0003-2551-6428)
- Nerida G. Wilson (ORCID: https://orcid.org/0000-0002-0784-0200)
- Dalila Destanović (ORCID: https://orcid.org/0000-0002-3744-5789)
- Kirstin Dion
- Ozren Bogdanović (ORCID: https://orcid.org/0000-0001-5680-0056)
- River B. Abedon
- Maria E. Albinsson
- Itziar Álvarez Trasobares (ORCID: https://orcid.org/0009-0008-4768-459X)
- D. A. Ramirez (ORCID: https://orcid.org/0009-0009-4164-0294)
- Lourdes M. Rojas
- Jenn M. Coughlan
- C Gabriela Mayorga-Adame
Institutions
- Universidade dos Açores (PT)
- Griffith University (AU)
- Centre National de la Recherche Scientifique (FR)
- The University of Sydney (AU)
- Allen Institute for Brain Science (US)
- Monterey Bay Aquarium Research Institute (US)
- Oregon Research Institute (US)
- University of Connecticut (US)
- Animal Welfare Institute (US)
- Austral University of Chile (CL)
- Queen Mary University of London (GB)
- Science Foundation Ireland (IE)
- University of Oregon (US)
- Georgetown University (US)
- Hokkaido University (JP)
- University College Cork (IE)
- Field Museum of Natural History (US)
- Universidad Católica del Norte (CL)
- UNSW Sydney (AU)
- Yale University (US)
- Sorbonne Université (FR)
- University of Gdańsk (PL)
- Western Australian Museum (AU)
- Centro Andaluz de Biología del Desarrollo (ES)
- Enoshima Aquarium (JP)
- NOAA National Marine Fisheries Service Pacific Islands Fisheries Science Center (US)
- Robert S. Peabody Museum of Archaeology (US)
- Sydney Institute of Marine Science (AU)
- Allen Institute (US)
- Instituto de Ciencias Marinas de Andalucía (ES)
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer (FR)
- University of Guam (GU)
- Nelson Mandela University (ZA)
Publication Details
- Journal
- Current Biology
- Published
- 2025-06-19
- DOI
- https://doi.org/10.1016/j.cub.2025.05.066
- Citations
- 8
- Primary Topic
- Marine Invertebrate Physiology and Ecology
- Type
- article
- Field-Weighted Citation Impact
- 34.63