1
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Cordone A, Selci M, Barosa B, Bastianoni A, Bastoni D, Bolinesi F, Capuozzo R, Cascone M, Correggia M, Corso D, Di Iorio L, Misic C, Montemagno F, Ricciardelli A, Saggiomo M, Tonietti L, Mangoni O, Giovannelli D. Surface Bacterioplankton Community Structure Crossing the Antarctic Circumpolar Current Fronts. Microorganisms 2023; 11:microorganisms11030702. [PMID: 36985275 PMCID: PMC10054113 DOI: 10.3390/microorganisms11030702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/28/2023] [Accepted: 03/07/2023] [Indexed: 03/30/2023] Open
Abstract
The Antarctic Circumpolar Current (ACC) is the major current in the Southern Ocean, isolating the warm stratified subtropical waters from the more homogeneous cold polar waters. The ACC flows from west to east around Antarctica and generates an overturning circulation by fostering deep-cold water upwelling and the formation of new water masses, thus affecting the Earth's heat balance and the global distribution of carbon. The ACC is characterized by several water mass boundaries or fronts, known as the Subtropical Front (STF), Subantarctic Front (SAF), Polar Front (PF), and South Antarctic Circumpolar Current Front (SACCF), identified by typical physical and chemical properties. While the physical characteristics of these fronts have been characterized, there is still poor information regarding the microbial diversity of this area. Here we present the surface water bacterioplankton community structure based on 16S rRNA sequencing from 13 stations sampled in 2017 between New Zealand to the Ross Sea crossing the ACC Fronts. Our results show a distinct succession in the dominant bacterial phylotypes present in the different water masses and suggest a strong role of sea surface temperatures and the availability of Carbon and Nitrogen in controlling community composition. This work represents an important baseline for future studies on the response of Southern Ocean epipelagic microbial communities to climate change.
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Affiliation(s)
- Angelina Cordone
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Matteo Selci
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Bernardo Barosa
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Alessia Bastianoni
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Deborah Bastoni
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Francesco Bolinesi
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Rosaria Capuozzo
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Martina Cascone
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Monica Correggia
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Davide Corso
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Luciano Di Iorio
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
| | - Cristina Misic
- Dipartimento di Scienze della Terra, Dell'Ambiente e della Vita, Universitá di Genova, 16132 Genova, Italy
| | | | | | | | - Luca Tonietti
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
- Department of Science and Technology, University of Naples Parthenope, 80143 Naples, Italy
| | - Olga Mangoni
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
- Consorzio Nazionale Interuniversitario delle Scienze del Mare (CoNISMa), 00196 Rome, Italy
| | - Donato Giovannelli
- Department of Biology, University of Naples Federico II, 80126 Naples, Italy
- Institute of Marine Biological Resources and Biotechnologies, National Research Council, 60125 Ancona, Italy
- Earth-Life Science Institute, Tokyo Institute for Technology, Tokyo 152-8552, Japan
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, NJ 08901, USA
- Marine Chemistry and Geology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02540, USA
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2
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Okanishi M, Kohtsuka H, Wu Q, Shinji J, Shibata N, Tamada T, Nakano T, Minamoto T. Development of two new sets of PCR primers for eDNA metabarcoding of brittle stars (Echinodermata, Ophiuroidea). METABARCODING AND METAGENOMICS 2023. [DOI: 10.3897/mbmg.7.94298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Brittle stars (class Ophiuroidea) are marine invertebrates comprising approximately 2,100 extant species, and are considered to constitute the most diverse taxon of the phylum Echinodermata. As a non-invasive method for monitoring biodiversity, we developed two new sets of PCR primers for metabarcoding environmental DNA (eDNA) from brittle stars. The new primer sets were designed to amplify 2 short regions of the mitochondrial 16S rRNA gene, comprising a conserved region (111–115 bp, 112 bp on average; named “16SOph1”) and a hyper-variable region (180–195 bp, 185 bp on average; named “16SOph2”) displaying interspecific variation. The performance of the primers was tested using eDNA obtained from two sources: a) rearing water of an 2.5 or 170 L aquarium tanks containing 15 brittle star species and b) from natural seawater collected around Misaki, the Pacific coast of central Japan, at depths ranging from shallow (2 m) to deep (> 200 m) sea. To build a reference library, we obtained 16S rRNA sequences of brittle star specimens collected from around Misaki and from similar depths in Japan, and sequences registered in International Nucleotide Sequence Database Collaboration. As a result of comparison of the obtained eDNA sequences with the reference library 37 (including cryptic species) and 26 brittle star species were detected with certain identities by 16SOph1 and 16SOph2 analyses, respectively. In shallow water, the number of species and reads other than the brittle stars detected with 16SOph1 was less than 10% of the total number. On the other hand, the number of brittle star species and reads detected with 16SOph2 was less than half of the total number, and the number of detected non-brittle star metazoan species ranged from 20 to 46 species across 6 to 8 phyla (only the reads at the “Tank” were less than 0.001%). The number of non-brittle star species and reads at 80 m was less than 10% with both of the primer sets. These findings suggest that 16SOph1 is specific to the brittle star and 16SOph2 is suitable for a variety of marine metazoans. It appears, however, that further optimization of primer sequences would still be necessary to avoid possible PCR dropouts from eDNA extracts. Moreover, a detailed elucidation of the brittle star fauna in the examined area, and the accurate identification of brittle star species in the current DNA databank is required.
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3
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Maroni PJ, Wilson NG. Multiple
Doris
“
kerguelenensis
” (Nudibranchia) species span the Antarctic Polar Front. Ecol Evol 2022; 12:e9333. [PMID: 36188511 PMCID: PMC9486823 DOI: 10.1002/ece3.9333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/25/2022] [Accepted: 08/30/2022] [Indexed: 11/27/2022] Open
Abstract
Despite strong historical biogeographical links between benthic faunal assemblages of the Magellan region of South America and the Antarctic Peninsula, very few studies have documented contemporary movement and gene flow in or out of the Southern Ocean, especially across the Antarctic Polar Front (APF). In fact, oceanographic barriers such as the APF and Antarctica's long geologic isolation have substantially separated the continents and facilitated the evolution of endemic marine taxa found within the Antarctic region. The Southern Ocean benthic sea slug complex, Doris “kerguelenensis,” are a group of direct‐developing, simultaneous hermaphrodites that lack a dispersive larval stage. To date, there are 59 highly divergent species known within this complex. Here, we provide evidence to show intraspecific genetic connectivity occurs across the APF for multiple species within the D. “kerguelenensis” nudibranch species complex. We addressed questions of genetic connectivity by examining the phylogeographic structure of the three best‐sampled D. “kerguelenensis” species and another three trans‐APF species using the protein coding mtDNA gene, cytochrome oxidase I. We also highlight alternative refugia uses among species with the same life history traits (i.e., benthic and direct developers) and for some species, extremely large distributions are established (e.g., circumpolarity). By improving our sampling of these nudibranchs, we gain better insight into the population structure and connectivity of the Antarctic region. This work also demonstrates how difficult it is to make generalizations across Antarctic marine species, even among ecologically‐similar, closely related species.
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Affiliation(s)
- Paige J. Maroni
- School of Biological Sciences (M092) University of Western Australia Crawley Western Australia Australia
- Western Australian Museum, Research & Collections Welshpool Western Australia Australia
| | - Nerida G. Wilson
- School of Biological Sciences (M092) University of Western Australia Crawley Western Australia Australia
- Western Australian Museum, Research & Collections Welshpool Western Australia Australia
- Securing Antarctica's Environmental Future Western Australian Museum Welshpool Western Australia Australia
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4
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Cowart DA, Schiaparelli S, Alvaro MC, Cecchetto M, Le Port AS, Jollivet D, Hourdez S. Origin, diversity, and biogeography of Antarctic scale worms (Polychaeta: Polynoidae): a wide-scale barcoding approach. Ecol Evol 2022; 12:e9093. [PMID: 35866013 PMCID: PMC9288932 DOI: 10.1002/ece3.9093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 05/06/2022] [Accepted: 05/23/2022] [Indexed: 11/14/2022] Open
Abstract
The Antarctic marine environment hosts diversified and highly endemic benthos owing to its unique geologic and climatic history. Current warming trends have increased the urgency of understanding Antarctic species history to predict how environmental changes will impact ecosystem functioning. Antarctic benthic lineages have traditionally been examined under three hypotheses: (1) high endemism and local radiation, (2) emergence of deep‐sea taxa through thermohaline circulation, and (3) species migrations across the Polar Front. In this study, we investigated which hypotheses best describe benthic invertebrate origins by examining Antarctic scale worms (Polynoidae). We amassed 691 polynoid sequences from the Southern Ocean and neighboring areas: the Kerguelen and Tierra del Fuego (South America) archipelagos, the Indian Ocean, and waters around New Zealand. We performed phylogenetic reconstructions to identify lineages across geographic regions, aided by mitochondrial markers cytochrome c oxidase subunit I (Cox1) and 16S ribosomal RNA (16S). Additionally, we produced haplotype networks at the species scale to examine genetic diversity, biogeographic separations, and past demography. The Cox1 dataset provided the most illuminating insights into the evolution of polynoids, with a total of 36 lineages identified. Eunoe sp. was present at Tierra del Fuego and Kerguelen, in favor of the latter acting as a migration crossroads. Harmothoe fuligineum, widespread around the Antarctic continent, was also present but isolated at Kerguelen, possibly resulting from historical freeze–thaw cycles. The genus Polyeunoa appears to have diversified prior to colonizing the continent, leading to the co‐occurrence of at least three cryptic species around the Southern and Indian Oceans. Analyses identified that nearly all populations are presently expanding following a bottleneck event, possibly caused by habitat reduction from the last glacial episodes. Findings support multiple origins for contemporary Antarctic polynoids, and some species investigated here provide information on ancestral scenarios of (re)colonization. First, it is apparent that species collected from the Antarctic continent are endemic, as the absence of closely related species in the Kerguelen and Tierra del Fuego datasets for most lineages argues in favor of Hypothesis 1 of local origin. Next, Eunoe sp. and H. fuligineum, however, support the possibility of Kerguelen and other sub‐Antarctic islands acting as a crossroads for larvae of some species, in support of Hypothesis 3. Finally, the genus Polyeunoa, conversely, is found at depths greater than 150 m and may have a deep origin, in line with Hypothesis 2. These “non endemic” groups, nevertheless, have a distribution that is either north or south of the Antarctic Polar Front, indicating that there is still a barrier to dispersal, even in the deep sea.
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Affiliation(s)
- Dominique A Cowart
- Department of Evolution, Ecology, and Behavior University of Illinois at Urbana - Champaign Urbana Illinois USA.,Company for Open Ocean Observations and Logging (COOOL) La Réunion France
| | - Stefano Schiaparelli
- Department of Earth, Environmental and Life Science (DiSTAV) University of Genoa Genoa Italy.,Italian National Antarctic Museum (MNA, Section of Genoa) University of Genoa Genoa Italy
| | - Maria Chiara Alvaro
- Department of Earth, Environmental and Life Science (DiSTAV) University of Genoa Genoa Italy
| | - Matteo Cecchetto
- Department of Earth, Environmental and Life Science (DiSTAV) University of Genoa Genoa Italy.,Italian National Antarctic Museum (MNA, Section of Genoa) University of Genoa Genoa Italy
| | - Anne-Sophie Le Port
- CNRS UMR 7144 'Adaptation et Diversité en Milieux Marins' (AD2M) Team 'Dynamique de la Diversité Marine' (DyDiv), Station Biologique de Roscoff Sorbonne Université Roscoff France
| | - Didier Jollivet
- CNRS UMR 7144 'Adaptation et Diversité en Milieux Marins' (AD2M) Team 'Dynamique de la Diversité Marine' (DyDiv), Station Biologique de Roscoff Sorbonne Université Roscoff France
| | - Stephane Hourdez
- CNRS UMR 7144 'Adaptation et Diversité en Milieux Marins' (AD2M) Team 'Dynamique de la Diversité Marine' (DyDiv), Station Biologique de Roscoff Sorbonne Université Roscoff France.,Laboratoire d'Ecogéochimie des Environnements Benthiques (LECOB), Observatoire Océanologique de Banyuls UMR 8222 CNRS-Sorbonne Université Banyuls-sur-mer France
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5
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Lessios HA, Hendler G. Mitochondrial phylogeny of the brittle star genus Ophioderma. Sci Rep 2022; 12:5304. [PMID: 35351912 PMCID: PMC8964800 DOI: 10.1038/s41598-022-08944-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 03/11/2022] [Indexed: 11/09/2022] Open
Abstract
We reconstructed the mitochondrial phylogeny of the species of the brittle star genus Ophioderma, using sequences of the Cytochrome Oxidase I gene (COI) to address four questions: (i) Are the species of Ophioderma described on morphological evidence reflected in mitochondrial genealogy? (ii) Which species separated from which? (iii) When did speciation events occur? (iv) What is the rate of COI evolution in ophiuroids? We found that most of the 22 described species we sampled coincide with monophyletic clusters of COI sequences, but there are exceptions, most notably in the eastern Pacific, in which three undescribed species were indicated. The COI phylogeny lacks resolution in the deeper nodes, but it does show that there are four species pairs, the members of which are found on either side of the central American Isthmus. Two pairs with a genetic distance of ~ 4% between Atlantic and Pacific members were probably split during the final stages of Isthmus completion roughly 3 million years ago. The rate of divergence provided by these pairs allowed the calibration of a relaxed molecular clock. Estimated dates of divergence indicate that the lineages leading to extant species coalesce at times much older than congeneric species in other classes of echinoderms, suggesting that low extinction rates may be one of the reasons that ophiuroids are species-rich. The mean rate of COI substitution in Ophioderma is three times slower than that of echinoids. Conclusions of previous mitochondrial DNA studies of ophiuroids that relied on echinoid calibrations to determine divergence times need to be revised.
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Affiliation(s)
- H A Lessios
- Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Panama.
| | - Gordon Hendler
- Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA, 90007, USA
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6
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Maroni PJ, Baker BJ, Moran AL, Woods HA, Avila C, Johnstone GJ, Stark JS, Kocot KM, Lockhart S, Saucède T, Rouse GW, Wilson NG. One Antarctic slug to confuse them all: the underestimated diversity of Doris kerguelenensis. INVERTEBR SYST 2022. [DOI: 10.1071/is21073] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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7
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Schwob G, Segovia NI, González-Wevar C, Cabrol L, Orlando J, Poulin E. Exploring the Microdiversity Within Marine Bacterial Taxa: Toward an Integrated Biogeography in the Southern Ocean. Front Microbiol 2021; 12:703792. [PMID: 34335536 PMCID: PMC8317501 DOI: 10.3389/fmicb.2021.703792] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/23/2021] [Indexed: 11/13/2022] Open
Abstract
Most of the microbial biogeographic patterns in the oceans have been depicted at the whole community level, leaving out finer taxonomic resolution (i.e., microdiversity) that is crucial to conduct intra-population phylogeographic study, as commonly done for macroorganisms. Here, we present a new approach to unravel the bacterial phylogeographic patterns combining community-wide survey by 16S rRNA gene metabarcoding and intra-species resolution through the oligotyping method, allowing robust estimations of genetic and phylogeographic indices, and migration parameters. As a proof-of-concept, we focused on the bacterial genus Spirochaeta across three distant biogeographic provinces of the Southern Ocean; maritime Antarctica, sub-Antarctic Islands, and Patagonia. Each targeted Spirochaeta operational taxonomic units were characterized by a substantial intrapopulation microdiversity, and significant genetic differentiation and phylogeographic structure among the three provinces. Gene flow estimations among Spirochaeta populations support the role of the Antarctic Polar Front as a biogeographic barrier to bacterial dispersal between Antarctic and sub-Antarctic provinces. Conversely, the Antarctic Circumpolar Current appears as the main driver of gene flow, connecting sub-Antarctic Islands with Patagonia and maritime Antarctica. Additionally, historical processes (drift and dispersal limitation) govern up to 86% of the spatial turnover among Spirochaeta populations. Overall, our approach bridges the gap between microbial and macrobial ecology by revealing strong congruency with macroorganisms distribution patterns at the populational level, shaped by the same oceanographic structures and ecological processes.
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Affiliation(s)
- Guillaume Schwob
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Instituto de Ecología y Biodiversidad, Santiago, Chile
| | - Nicolás I. Segovia
- Instituto de Ecología y Biodiversidad, Santiago, Chile
- Universidad Católica del Norte, Coquimbo, Chile
| | - Claudio González-Wevar
- Instituto de Ecología y Biodiversidad, Santiago, Chile
- Facultad de Ciencias, Centro Fondap IDEAL, Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile
| | - Léa Cabrol
- Instituto de Ecología y Biodiversidad, Santiago, Chile
- Aix Marseille University, Univ Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), Marseille, France
| | - Julieta Orlando
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Elie Poulin
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Instituto de Ecología y Biodiversidad, Santiago, Chile
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8
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Levicoy D, Rosenfeld S, Cárdenas L. Divergence time and species delimitation of microbivalves in the Southern Ocean: the case of Kidderia species. Polar Biol 2021; 44:1365-1377. [PMID: 34092908 PMCID: PMC8169414 DOI: 10.1007/s00300-021-02885-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 05/10/2021] [Accepted: 05/19/2021] [Indexed: 11/18/2022]
Abstract
The systematics of Subantarctic and Antarctic near-shore marine benthic invertebrates requires major revision and highlights the necessity to incorporate additional sources of information in the specimen identification chart in the Southern Ocean (SO). In this study, we aim to improve our understanding of the biodiversity of Kidderia (Dall 1876) through molecular and morphological comparisons of Antarctic and Subantarctic taxa. The microbivalves of the genus Kidderia are small brooding organisms that inhabit intertidal and shallow subtidal rocky ecosystems. This genus represents an interesting model to test the vicariance and dispersal hypothesis in the biogeography of the SO. However, the description of Kidderia species relies on a few morphological characters and biogeographic records that raise questions about the true diversity in the group. Here we will define the specimens collected with genetic tools, delimiting their respective boundaries across provinces of the SO, validating the presence of two species of Kidderia. Through the revision of taxonomic issues and species delimitation, it was possible to report that the Antarctic species is Kidderia subquadrata and the species recorded in the Subantarctic islands Diego Ramirez, South Georgia and the Kerguelen Archipelago is Kidderia minuta. The divergence time estimation suggests the origin and diversification of Kidderia lineages are related to historical vicariant processes probably associated with the separation of the continental landmasses close to the late Eocene.
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Affiliation(s)
- Daniela Levicoy
- Centro FONDAP- IDEAL, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Instituto de Ciencias Ambientales & Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Independencia 641, P.O. Box 567, Valdivia, Chile
| | - Sebastián Rosenfeld
- Laboratorio de Ecología Molecular, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras #3425, Ñuñoa, Santiago Chile.,Laboratorio de Ecosistemas Marinos Antárticos y Subantárticos, Universidad de Magallanes, Avenida Bulnes 01890, Punta Arenas, Chile.,Instituto de Ecología y Biodiversidad, Las Palmeras 3425, Ñuñoa, Santiago Chile.,Centro de Investigación Gaia-Antártica, Universidad de Magallanes, Avenida Bulnes 01855, Punta Arenas, Chile
| | - Leyla Cárdenas
- Centro FONDAP- IDEAL, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Instituto de Ciencias Ambientales & Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Independencia 641, P.O. Box 567, Valdivia, Chile
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9
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Moles J, Derkarabetian S, Schiaparelli S, Schrödl M, Troncoso JS, Wilson NG, Giribet G. An approach using ddRADseq and machine learning for understanding speciation in Antarctic Antarctophilinidae gastropods. Sci Rep 2021; 11:8473. [PMID: 33875688 PMCID: PMC8055997 DOI: 10.1038/s41598-021-87244-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 03/25/2021] [Indexed: 02/02/2023] Open
Abstract
Sampling impediments and paucity of suitable material for molecular analyses have precluded the study of speciation and radiation of deep-sea species in Antarctica. We analyzed barcodes together with genome-wide single nucleotide polymorphisms obtained from double digestion restriction site-associated DNA sequencing (ddRADseq) for species in the family Antarctophilinidae. We also reevaluated the fossil record associated with this taxon to provide further insights into the origin of the group. Novel approaches to identify distinctive genetic lineages, including unsupervised machine learning variational autoencoder plots, were used to establish species hypothesis frameworks. In this sense, three undescribed species and a complex of cryptic species were identified, suggesting allopatric speciation connected to geographic or bathymetric isolation. We further observed that the shallow waters around the Scotia Arc and on the continental shelf in the Weddell Sea present high endemism and diversity. In contrast, likely due to the glacial pressure during the Cenozoic, a deep-sea group with fewer species emerged expanding over great areas in the South-Atlantic Antarctic Ridge. Our study agrees on how diachronic paleoclimatic and current environmental factors shaped Antarctic communities both at the shallow and deep-sea levels, promoting Antarctica as the center of origin for numerous taxa such as gastropod mollusks.
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Affiliation(s)
- Juan Moles
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA.
- SNSB-Bavarian State Collection of Zoology, Münchhausenstrasse 21, 81247, Munich, Germany.
- Biozentrum Ludwig Maximilians University and GeoBio-Center LMU Munich, Munich, Germany.
| | - Shahan Derkarabetian
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
| | - Stefano Schiaparelli
- DiSTAV, University of Genoa, C.so Europa 26, 16132, Genoa, Italy
- Italian National Antarctic Museum (MNA, Section of Genoa), Viale Benedetto XV n. 5, 16132, Genoa, Italy
| | - Michael Schrödl
- SNSB-Bavarian State Collection of Zoology, Münchhausenstrasse 21, 81247, Munich, Germany
- Biozentrum Ludwig Maximilians University and GeoBio-Center LMU Munich, Munich, Germany
| | - Jesús S Troncoso
- Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, Campus Lagoas-Marcosende s/n, 36200, Vigo, Spain
| | - Nerida G Wilson
- Collections and Research, Western Australian Museum, Welshpool DC, Locked Bag 49, Perth, WA, 6986, Australia
- School of Biological Sciences, University of Western Australia, 35 Stirling Hwy, Crawley, WA, 6009, Australia
| | - Gonzalo Giribet
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA, 02138, USA
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10
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Hernández-Hernández T, Miller EC, Román-Palacios C, Wiens JJ. Speciation across the Tree of Life. Biol Rev Camb Philos Soc 2021; 96:1205-1242. [PMID: 33768723 DOI: 10.1111/brv.12698] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/13/2021] [Accepted: 02/16/2021] [Indexed: 01/04/2023]
Abstract
Much of what we know about speciation comes from detailed studies of well-known model systems. Although there have been several important syntheses on speciation, few (if any) have explicitly compared speciation among major groups across the Tree of Life. Here, we synthesize and compare what is known about key aspects of speciation across taxa, including bacteria, protists, fungi, plants, and major animal groups. We focus on three main questions. Is allopatric speciation predominant across groups? How common is ecological divergence of sister species (a requirement for ecological speciation), and on what niche axes do species diverge in each group? What are the reproductive isolating barriers in each group? Our review suggests the following patterns. (i) Based on our survey and projected species numbers, the most frequent speciation process across the Tree of Life may be co-speciation between endosymbiotic bacteria and their insect hosts. (ii) Allopatric speciation appears to be present in all major groups, and may be the most common mode in both animals and plants, based on non-overlapping ranges of sister species. (iii) Full sympatry of sister species is also widespread, and may be more common in fungi than allopatry. (iv) Full sympatry of sister species is more common in some marine animals than in terrestrial and freshwater ones. (v) Ecological divergence of sister species is widespread in all groups, including ~70% of surveyed species pairs of plants and insects. (vi) Major axes of ecological divergence involve species interactions (e.g. host-switching) and habitat divergence. (vii) Prezygotic isolation appears to be generally more widespread and important than postzygotic isolation. (viii) Rates of diversification (and presumably speciation) are strikingly different across groups, with the fastest rates in plants, and successively slower rates in animals, fungi, and protists, with the slowest rates in prokaryotes. Overall, our study represents an initial step towards understanding general patterns in speciation across all organisms.
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Affiliation(s)
- Tania Hernández-Hernández
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A.,Catedrática CONACYT asignada a LANGEBIO-UGA Cinvestav, Libramiento Norte Carretera León Km 9.6, 36821, Irapuato, Guanajuato, Mexico
| | - Elizabeth C Miller
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
| | - Cristian Román-Palacios
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
| | - John J Wiens
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
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11
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Levicoy D, Flores K, Rosenfeld S, Cárdenas L. Phylogeography and genetic diversity of the microbivalve Kidderia subquadrata, reveals new data from West Antarctic Peninsula. Sci Rep 2021; 11:5705. [PMID: 33707560 PMCID: PMC7952419 DOI: 10.1038/s41598-021-85042-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 02/19/2021] [Indexed: 12/14/2022] Open
Abstract
It is well established that Antarctic biodiversity has been strongly influenced by rapid climatic fluctuations during the Quaternary. Marine invertebrates from Antarctica constitute an interesting lens through which to study the impacts of the last glacial periods as glaciation impacted the distribution and intraspecific genetic variation of these animals. However, the impact on the spatial genetic distribution and historical demography of local processes in areas adjacent to the West Antarctic Peninsula (WAP) is less clear. Here we present new genetic information on the bivalve Kidderia subquadrata, a small mollusk that inhabits intertidal rocky island ecosystems throughout the WAP. Using a phylogeographical approach, we examined the spatial patterns of genetic diversity in this brooder species to test the hypothesis of strong genetic structure in incubating organisms and the hypothesis of glacial refugia in organisms with limited dispersion. We found evidence of strong genetic structure among populations of the WAP and a recent expansion in the South Shetland Islands. Our findings are concordant with the predictions that incubating organisms, abundant in Antarctica, present a strong genetic structure among their populations and also support the hypothesis of glacial refugia in organisms with limited dispersion. The effect of the coastal current pattern in the WAP is suggested as a driver to the local spatial dynamics of the genetic diversity distribution. Although genetic information about this microbivalve is still scarce, the knowledge reported here has increased our understanding of the evolutionary patterns of this organism that is endemic to the Southern Ocean.
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Affiliation(s)
- Daniela Levicoy
- Centro FONDAP- IDEAL, Instituto de Ciencias Ambientales and Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Independencia 641, P.O. Box 567, Valdivia, Punta Arenas, Chile
| | - Kamilla Flores
- Centro FONDAP- IDEAL, Instituto de Ciencias Ambientales and Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Independencia 641, P.O. Box 567, Valdivia, Punta Arenas, Chile
| | - Sebastián Rosenfeld
- Laboratorio de Ecosistemas Marinos Antárticos Y Subantárticos, Universidad de Magallanes, Casilla 113-D, Punta Arenas, Chile.,Laboratorio de Ecología Molecular, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras # 3425, Ñuñoa, Santiago, Chile.,Instituto de Ecología y Biodiversidad (IEB), Las Palmeras # 3425, Ñuñoa, Santiago, Chile
| | - Leyla Cárdenas
- Centro FONDAP- IDEAL, Instituto de Ciencias Ambientales and Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Independencia 641, P.O. Box 567, Valdivia, Punta Arenas, Chile.
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12
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Ansaloni F, Gerdol M, Torboli V, Fornaini NR, Greco S, Giulianini PG, Coscia MR, Miccoli A, Santovito G, Buonocore F, Scapigliati G, Pallavicini A. Cold Adaptation in Antarctic Notothenioids: Comparative Transcriptomics Reveals Novel Insights in the Peculiar Role of Gills and Highlights Signatures of Cobalamin Deficiency. Int J Mol Sci 2021; 22:ijms22041812. [PMID: 33670421 PMCID: PMC7918649 DOI: 10.3390/ijms22041812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/04/2021] [Accepted: 02/08/2021] [Indexed: 01/13/2023] Open
Abstract
Far from being devoid of life, Antarctic waters are home to Cryonotothenioidea, which represent one of the fascinating cases of evolutionary adaptation to extreme environmental conditions in vertebrates. Thanks to a series of unique morphological and physiological peculiarities, which include the paradigmatic case of loss of hemoglobin in the family Channichthyidae, these fish survive and thrive at sub-zero temperatures. While some of the distinctive features of such adaptations have been known for decades, our knowledge of their genetic and molecular bases is still limited. We generated a reference de novo assembly of the icefish Chionodraco hamatus transcriptome and used this resource for a large-scale comparative analysis among five red-blooded Cryonotothenioidea, the sub-Antarctic notothenioid Eleginops maclovinus and seven temperate teleost species. Our investigation targeted the gills, a tissue of primary importance for gaseous exchange, osmoregulation, ammonia excretion, and its role in fish immunity. One hundred and twenty genes were identified as significantly up-regulated in Antarctic species and surprisingly shared by red- and white-blooded notothenioids, unveiling several previously unreported molecular players that might have contributed to the evolutionary success of Cryonotothenioidea in Antarctica. In particular, we detected cobalamin deficiency signatures and discussed the possible biological implications of this condition concerning hematological alterations and the heavy parasitic loads typically observed in all Cryonotothenioidea.
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Affiliation(s)
- Federico Ansaloni
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
- International School for Advanced Studies, 34136 Trieste, Italy
| | - Marco Gerdol
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
- Correspondence:
| | - Valentina Torboli
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
| | - Nicola Reinaldo Fornaini
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
- Department of Cell Biology, Charles University, 12800 Prague, Czech Republic
| | - Samuele Greco
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
| | - Piero Giulio Giulianini
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
| | - Maria Rosaria Coscia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, 80131 Naples, Italy;
| | - Andrea Miccoli
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, 01100 Viterbo, Italy; (A.M.); (F.B.); (G.S.)
| | | | - Francesco Buonocore
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, 01100 Viterbo, Italy; (A.M.); (F.B.); (G.S.)
| | - Giuseppe Scapigliati
- Department for Innovation in Biological, Agro-Food and Forest Systems, University of Tuscia, 01100 Viterbo, Italy; (A.M.); (F.B.); (G.S.)
| | - Alberto Pallavicini
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; (F.A.); (V.T.); (N.R.F.); (S.G.); (P.G.G.); (A.P.)
- Anton Dohrn Zoological Station, 80122 Naples, Italy
- National Institute of Oceanography and Experimental Geophysics, 34010 Trieste, Italy
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13
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Ziegler AF, Hahn-Woernle L, Powell B, Smith CR. Larval Dispersal Modeling Suggests Limited Ecological Connectivity Between Fjords on the West Antarctic Peninsula. Integr Comp Biol 2020; 60:1369-1385. [PMID: 32617573 DOI: 10.1093/icb/icaa094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Larval dispersal is a key process for community assembly and population maintenance in the marine environment, yet it is extremely difficult to measure at ecologically relevant spatio-temporal scales. We used a high-resolution hydrodynamic model and particle-tracking model to explore the dispersal of simulated larvae in a hydrographically complex region of fjords on the West Antarctic Peninsula. Modeled larvae represented two end members of dispersal potential observed in Antarctic benthos resulting from differing developmental periods and swimming behavior. For simulations of low dispersing larvae (pre-competency period = 8 days, settlement period = 15 days, swimming downward) self-recruitment within fjords was important, with no larval settlement occurring in adjacent fjords <50 km apart. For simulations of highly dispersing organisms (pre-competency period = 35-120 days, settlement period = 30-115 days, no swimming behavior), dispersal between fjords occurred when larvae were in the water column for at least 35 days, but settlement was rarely successful even for larvae spending up to 150 days in the plankton. The lack of ecological connectivity between fjords within a single spawning event suggests that these fjords harbor ecologically distinct populations in which self-recruitment may maintain populations, and genetic connectivity between fjords is likely achieved through stepping-stone dispersal. Export of larvae from natal fjord populations to the broader shelf region (>100 km distance) occurred within surface layers (<100 m depth) and was enhanced by episodic katabatic wind events that may be common in glaciomarine fjords worldwide.
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Affiliation(s)
- Amanda F Ziegler
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Lisa Hahn-Woernle
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Brian Powell
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Craig R Smith
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
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14
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González-Wevar CA, Segovia NI, Rosenfeld S, Noll D, Maturana CS, Hüne M, Naretto J, Gérard K, Díaz A, Spencer HG, Saucède T, Féral JP, Morley SA, Brickle P, Wilson NG, Poulin E. Contrasting biogeographical patterns in Margarella (Gastropoda: Calliostomatidae: Margarellinae) across the Antarctic Polar Front. Mol Phylogenet Evol 2020; 156:107039. [PMID: 33310059 DOI: 10.1016/j.ympev.2020.107039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/07/2020] [Indexed: 11/25/2022]
Abstract
Members of the trochoidean genus Margarella (Calliostomatidae) are broadly distributed across Antarctic and sub-Antarctic ecosystems. Here we used novel mitochondrial and nuclear gene sequences to clarify species boundaries and phylogenetic relationships among seven nominal species distributed on either side of the Antarctic Polar Front (APF). Molecular reconstructions and species-delimitation analyses recognized only four species: M. antarctica (the Antarctic Peninsula), M. achilles (endemic to South Georgia), M. steineni (South Georgia and Crozet Island) and the morphologically variable M. violacea (=M. expansa, M. porcellana and M. pruinosa), with populations in southern South America, the Falkland/Malvinas, Crozet and Kerguelen Islands. Margarella violacea and M. achilles are sister species, closely related to M. steineni, with M. antarctica sister to all these. This taxonomy reflects contrasting biogeographic patterns on either side of the APF in the Southern Ocean. Populations of Margarella north of the APF (M. violacea) showed significant genetic variation but with many shared haplotypes between geographically distant populations. By contrast, populations south of the APF (M. antarctica, M. steineni and M. achilles) exhibited fewer haplotypes and comprised three distinct species, each occurring across a separate geographical range. We hypothesize that the biogeographical differences may be the consequence of the presence north of the APF of buoyant kelps - potential long-distance dispersal vectors for these vetigastropods with benthic-protected development - and their near-absence to the south. Finally, we suggest that the low levels of genetic diversity within higher-latitude Margarella reflect the impact of Quaternary glacial cycles that exterminated local populations during their maxima.
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Affiliation(s)
- C A González-Wevar
- Instituto de Ciencias Marinas y Limnológicas (ICML), Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile; Instituto Milenio de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile; Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Universidad Austral de Chile, Casilla 567, Valdivia, Chile.
| | - N I Segovia
- Instituto Milenio de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile
| | - S Rosenfeld
- Instituto Milenio de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile; Laboratorio de Ecosistemas Marinos Antárticos y Subantárticos, Universidad de Magallanes, Chile
| | - D Noll
- Instituto Milenio de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile
| | - C S Maturana
- Instituto Milenio de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile
| | - M Hüne
- Instituto Milenio de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile
| | - J Naretto
- Instituto Milenio de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile
| | - K Gérard
- Laboratorio de Ecosistemas Marinos Antárticos y Subantárticos, Universidad de Magallanes, Chile
| | - A Díaz
- Departamento de Zoología, Universidad de Concepción, Barrio Universitario s/n, Concepción, Chile
| | - H G Spencer
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - T Saucède
- Biogéosciences, UMR CNRS 6282, Université de Bourgogne, 6, boulevard Gabriel, 21000, Dijon, France
| | - J-P Féral
- AMU/CNRS/IRD/AU-IMBE-Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale, UMR 7263, Station Marine d'Endoume, Chemin de la Batterie des Lions, 13007 Marseille, France
| | - S A Morley
- British Antarctic Survey (BAS), Natural Environment Research Council. Madingley Road, High Cross, Cambridge CB30ET, UK
| | - P Brickle
- South Atlantic Environmental Research Institute (SAERI), PO Box 609, Stanley Cottage, Stanley, Falkland Islands, UK
| | - N G Wilson
- Collections & Research, Western Australian Museum, 49 Kew St, Welshpool 6106, Perth, WA, Australia; University of Western Australia, 35 Stirling Highway, Crawley 6009, WA, Australia
| | - E Poulin
- Instituto Milenio de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile
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15
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Fabri-Ruiz S, Navarro N, Laffont R, Danis B, Saucède T. Diversity of Antarctic Echinoids and Ecoregions of the Southern Ocean. BIOL BULL+ 2020. [DOI: 10.1134/s1062359020060047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Muñoz-Ramírez CP, Barnes DKA, Cárdenas L, Meredith MP, Morley SA, Roman-Gonzalez A, Sands CJ, Scourse J, Brante A. Gene flow in the Antarctic bivalve Aequiyoldia eightsii (Jay, 1839) suggests a role for the Antarctic Peninsula Coastal Current in larval dispersal. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200603. [PMID: 33047024 PMCID: PMC7540763 DOI: 10.1098/rsos.200603] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/21/2020] [Indexed: 05/12/2023]
Abstract
The Antarctic Circumpolar Current (ACC) dominates the open-ocean circulation of the Southern Ocean, and both isolates and connects the Southern Ocean biodiversity. However, the impact on biological processes of other Southern Ocean currents is less clear. Adjacent to the West Antarctic Peninsula (WAP), the ACC flows offshore in a northeastward direction, whereas the Antarctic Peninsula Coastal Current (APCC) follows a complex circulation pattern along the coast, with topographically influenced deflections depending on the area. Using genomic data, we estimated genetic structure and migration rates between populations of the benthic bivalve Aequiyoldia eightsii from the shallows of southern South America and the WAP to test the role of the ACC and the APCC in its dispersal. We found strong genetic structure across the ACC (between southern South America and Antarctica) and moderate structure between populations of the WAP. Migration rates along the WAP were consistent with the APCC being important for species dispersal. Along with supporting current knowledge about ocean circulation models at the WAP, migration from the tip of the Antarctic Peninsula to the Bellingshausen Sea highlights the complexities of Southern Ocean circulation. This study provides novel biological evidence of a role of the APCC as a driver of species dispersal and highlights the power of genomic data for aiding in the understanding of the influence of complex oceanographic processes in shaping the population structure of marine species.
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Affiliation(s)
- Carlos P. Muñoz-Ramírez
- Instituto de Entomología, Facultad de Ciencias Básicas, Universidad Metropolitana de Ciencias de la Educación, Santiago, Chile
- Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción, Chile
- Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Concepción, Chile
| | - David K. A. Barnes
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Leyla Cárdenas
- Centro FONDAP de Investigación Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, UniversidadAustral de Chile, Valdivia, Chile
| | - Michael P. Meredith
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - Simon A. Morley
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | | | - Chester J. Sands
- British Antarctic Survey, Natural Environment Research Council, Cambridge, UK
| | - James Scourse
- College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall TR10 9EZ, UK
| | - Antonio Brante
- Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción, Chile
- Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Concepción, Chile
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17
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Fabri-Ruiz S, Danis B, Navarro N, Koubbi P, Laffont R, Saucède T. Benthic ecoregionalization based on echinoid fauna of the Southern Ocean supports current proposals of Antarctic Marine Protected Areas under IPCC scenarios of climate change. GLOBAL CHANGE BIOLOGY 2020; 26:2161-2180. [PMID: 31919925 DOI: 10.1111/gcb.14988] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/20/2019] [Accepted: 12/27/2019] [Indexed: 06/10/2023]
Abstract
The Southern Ocean (SO) is among the regions on Earth that are undergoing regionally the fastest environmental changes. The unique ecological features of its marine life make it particularly vulnerable to the multiple effects of climate change. A network of Marine Protected Areas (MPAs) has started to be implemented in the SO to protect marine ecosystems. However, considering future predictions of the Intergovernmental Panel on Climate Change (IPCC), the relevance of current, static, MPAs may be questioned under future scenarios. In this context, the ecoregionalization approach can prove promising in identifying well-delimited regions of common species composition and environmental settings. These so-called ecoregions are expected to show similar biotic responses to environmental changes and can be used to define priority areas for the designation of new MPAs and the update of their current delimitation. In the present work, a benthic ecoregionalization of the entire SO is proposed for the first time based on abiotic environmental parameters and the distribution of echinoid fauna, a diversified and common member of Antarctic benthic ecosystems. A novel two-step approach was developed combining species distribution modeling with Random Forest and Gaussian Mixture modeling from species probabilities to define current ecoregions and predict future ecoregions under IPCC scenarios RCP 4.5 and 8.5. The ecological representativity of current and proposed MPAs of the SO is discussed with regard to the modeled benthic ecoregions. In all, 12 benthic ecoregions were determined under present conditions, they are representative of major biogeographic patterns already described. Our results show that the most dramatic changes can be expected along the Antarctic Peninsula, in East Antarctica and the sub-Antarctic islands under both IPCC scenarios. Our results advocate for a dynamic definition of MPAs, they also argue for improving the representativity of Antarctic ecoregions in proposed MPAs and support current proposals of Conservation of Antarctic Marine Living Resources for the creation of Antarctic MPAs.
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Affiliation(s)
- Salomé Fabri-Ruiz
- Biogéosciences, UMR CNRS/EPHE 6282, Université Bourgogne Franche-Comté, Dijon, France
- Laboratoire de Biologie Marine, Université Libre de Bruxelles, Brussels, Belgium
| | - Bruno Danis
- Laboratoire de Biologie Marine, Université Libre de Bruxelles, Brussels, Belgium
| | - Nicolas Navarro
- Biogéosciences, UMR CNRS/EPHE 6282, Université Bourgogne Franche-Comté, Dijon, France
- EPHE, PSL University, Paris, France
| | - Philippe Koubbi
- UFR 918 Terre Environnement et Biodiversité, Sorbonne Université, Paris Cedex 05, France
- IFREMER, Centre Manche mer du Nord. Laboratoire Halieutique de Manche-Mer du Nord, Boulogne-sur-Mer, France
| | - Rémi Laffont
- Biogéosciences, UMR CNRS/EPHE 6282, Université Bourgogne Franche-Comté, Dijon, France
| | - Thomas Saucède
- Biogéosciences, UMR CNRS/EPHE 6282, Université Bourgogne Franche-Comté, Dijon, France
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18
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Bogantes VE, Whelan NV, Webster K, Mahon AR, Halanych KM. Unrecognized diversity of a scale worm,Polyeunoa laevis(Annelida: Polynoidae), that feeds on soft coral. ZOOL SCR 2019. [DOI: 10.1111/zsc.12400] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Viktoria E. Bogantes
- Department of Biological Sciences Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University Auburn AL USA
| | - Nathan V. Whelan
- Southeast Conservation Genetics Lab Warm Springs Fish Technology Center United States Fish and Wildlife Service Auburn AL USA
- School of Fisheries, Aquaculture, and Aquatic Sciences Auburn University Auburn AL USA
| | - Katelynn Webster
- Department of Biological Sciences Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University Auburn AL USA
| | - Andrew R. Mahon
- Department of Biology Central Michigan University Mount Pleasant MI USA
| | - Kenneth M. Halanych
- Department of Biological Sciences Molette Biology Laboratory for Environmental and Climate Change Studies Auburn University Auburn AL USA
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19
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Jossart Q, Sands CJ, Sewell MA. Dwarf brooder versus giant broadcaster: combining genetic and reproductive data to unravel cryptic diversity in an Antarctic brittle star. Heredity (Edinb) 2019; 123:622-633. [PMID: 31073238 DOI: 10.1038/s41437-019-0228-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/08/2019] [Accepted: 04/18/2019] [Indexed: 11/09/2022] Open
Abstract
Poecilogony, or multiple developmental modes in a single species, is exceedingly rare. Several species described as poecilogenous were later demonstrated to be multiple (cryptic) species with a different developmental mode. The Southern Ocean is known to harbor a high proportion of brooders (Thorson's Rule) but with an increasing number of counter examples over recent years. Here we evaluated poecilogony vs. crypticism in the brittle star Astrotoma agassizii across the Southern Ocean. This species was initially described from South America as a brooder before some pelagic stages were identified in Antarctica. Reproductive and mitochondrial data were combined to unravel geographic and genetic variation of developmental modes. Our results indicate that A. agassizii is composed of seven well-supported and deeply divergent clades (I: Antarctica and South Georgia; II: South Georgia and Sub-Antarctic locations including Kerguelen, Patagonian shelf, and New Zealand; III-VI-VII: Patagonian shelf, IV-V: South Georgia). Two of these clades demonstrated strong size dimorphism when in sympatry and can be linked to differing developmental modes (Clade V: dwarf brooder vs. Clade I: giant broadcaster). Based on their restricted geographic distributions and on previous studies, it is likely that Clades III-VI-VII are brooders. Clade II is composed of different morphological species, A. agassizii and A. drachi, the latter originally used as the outgroup. By integrating morphology, reproductive, and molecular data we conclude that the variation identified in A. agassizii is best described as crypticism rather than poecilogony.
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Affiliation(s)
- Quentin Jossart
- University of Auckland, Auckland, New Zealand. .,British Antarctic Survey, Cambridge, UK. .,Vrije Universiteit Brussel, Brussels, Belgium.
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20
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Species delimitation in the presence of strong incomplete lineage sorting and hybridization: Lessons from Ophioderma (Ophiuroidea: Echinodermata). Mol Phylogenet Evol 2019; 131:138-148. [DOI: 10.1016/j.ympev.2018.11.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 11/15/2018] [Accepted: 11/16/2018] [Indexed: 01/01/2023]
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21
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Halanych KM, Mahon AR. Challenging Dogma Concerning Biogeographic Patterns of Antarctica and the Southern Ocean. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2018. [DOI: 10.1146/annurev-ecolsys-121415-032139] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Antarctica is enormous, cold, remote, and particularly sensitive to climate change. Most biological research below 60°S has focused on the isolated nature of the biota and how organisms have adapted to the cold and ice. However, biogeographic patterns in Antarctica and the Southern Ocean, and the processes explaining how those patterns came about, still await adequate explanation. Both terrestrial and marine organisms have been influenced by climatic change (e.g., glaciation), physical phenomena (e.g., oceanic currents), and/or potential barriers to gene flow (e.g., steep thermal gradients). Whereas the Antarctic region contains diverse and complex marine communities, terrestrial systems tend to be comparatively simple with limited diversity. Here, we challenge the current dogma used to explain the diversity and biogeographic patterns present in the Antarctic. We assert that relatively modern processes within the last few million years, rather than geo-logical events that occurred in the Eocene and Miocene, account for present patterns of biodiversity in the region. Additionally, reproductive life history stages appear to have little influence in structuring genetic patterns in the Antarctic, as currents and glacial patterns are noted to be more important drivers of organismal patterns of distribution. Finally, we highlight the need for additional sampling, high-throughput genomic approaches, and broad, multinational cooperation for addressing outstanding questions of Antarctic biogeography and biodiversity.
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Affiliation(s)
- Kenneth M. Halanych
- Molette Biology Laboratory for Environmental and Climate Change Studies, Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA
| | - Andrew R. Mahon
- Department of Biology, Central Michigan University, Mount Pleasant, Michigan 48859, USA
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22
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Fabri-Ruiz S, Danis B, David B, Saucède T. Can we generate robust species distribution models at the scale of the Southern Ocean? DIVERS DISTRIB 2018. [DOI: 10.1111/ddi.12835] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Salomé Fabri-Ruiz
- Biogéosciences; UMR 6282 CNRS; Université Bourgogne Franche-Comté; Dijon France
| | - Bruno Danis
- Laboratoire de Biologie Marine; Université Libre de Bruxelles (ULB); Brussels Belgium
| | - Bruno David
- Biogéosciences; UMR 6282 CNRS; Université Bourgogne Franche-Comté; Dijon France
- Muséum national d'Histoire naturelle; Paris France
| | - Thomas Saucède
- Biogéosciences; UMR 6282 CNRS; Université Bourgogne Franche-Comté; Dijon France
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Flaviani F, Schroeder DC, Lebret K, Balestreri C, Highfield AC, Schroeder JL, Thorpe SE, Moore K, Pasckiewicz K, Pfaff MC, Rybicki EP. Distinct Oceanic Microbiomes From Viruses to Protists Located Near the Antarctic Circumpolar Current. Front Microbiol 2018; 9:1474. [PMID: 30065704 PMCID: PMC6056678 DOI: 10.3389/fmicb.2018.01474] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 06/13/2018] [Indexed: 12/13/2022] Open
Abstract
Microbes occupy diverse ecological niches and only through recent advances in next generation sequencing technologies have the true microbial diversity been revealed. Furthermore, lack of perceivable marine barriers to genetic dispersal (i.e., mountains or islands) has allowed the speculation that organisms that can be easily transported by currents and therefore proliferate everywhere. That said, ocean currents are now commonly being recognized as barriers for microbial dispersal. Here we analyzed samples collected from a total of six stations, four located in the Indian Ocean, and two in the Southern Ocean. Amplicon sequencing was used to characterize both prokaryotic and eukaryotic plankton communities, while shotgun sequencing was used for the combined environmental DNA (eDNA), microbial eDNA (meDNA), and viral fractions. We found that Cyanobacteria dominated the prokaryotic component in the South-West Indian Ocean, while γ-Proteobacteria dominated the South-East Indian Ocean. A combination of γ- and α-Proteobacteria dominated the Southern Ocean. Alveolates dominated almost exclusively the eukaryotic component, with variation in the ratio of Protoalveolata and Dinoflagellata depending on station. However, an increase in haptophyte relative abundance was observed in the Southern Ocean. Similarly, the viral fraction was dominated by members of the order Caudovirales across all stations; however, a higher presence of nucleocytoplasmic large DNA viruses (mainly chloroviruses and mimiviruses) was observed in the Southern Ocean. To our knowledge, this is the first that a statistical difference in the microbiome (from viruses to protists) between the subtropical Indian and Southern Oceans. We also show that not all phylotypes can be found everywhere, and that meDNA is not a suitable resource for monitoring aquatic microbial diversity.
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Affiliation(s)
- Flavia Flaviani
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa.,Marine Biological Association of the United Kingdom, Citadel Hill, Plymouth, United Kingdom
| | - Declan C Schroeder
- Marine Biological Association of the United Kingdom, Citadel Hill, Plymouth, United Kingdom.,School of Biological Sciences, University of Reading, Reading, United Kingdom.,College of Veterinary Medicine, University of Minnesota Twin Cities, Minneapolis, MN, United States
| | - Karen Lebret
- Marine Biological Association of the United Kingdom, Citadel Hill, Plymouth, United Kingdom.,Limnology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Cecilia Balestreri
- Marine Biological Association of the United Kingdom, Citadel Hill, Plymouth, United Kingdom
| | - Andrea C Highfield
- Marine Biological Association of the United Kingdom, Citadel Hill, Plymouth, United Kingdom
| | - Joanna L Schroeder
- Marine Biological Association of the United Kingdom, Citadel Hill, Plymouth, United Kingdom
| | - Sally E Thorpe
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
| | - Karen Moore
- Exeter Sequencing Service, Biosciences, University of Exeter, Exeter, United Kingdom
| | - Konrad Pasckiewicz
- Exeter Sequencing Service, Biosciences, University of Exeter, Exeter, United Kingdom
| | - Maya C Pfaff
- Department of Environmental Affairs, Oceans and Coasts, Cape Town, South Africa
| | - Edward P Rybicki
- Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
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24
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Díaz A, Gérard K, González-Wevar C, Maturana C, Féral JP, David B, Saucède T, Poulin E. Genetic structure and demographic inference of the regular sea urchin Sterechinus neumayeri (Meissner, 1900) in the Southern Ocean: The role of the last glaciation. PLoS One 2018; 13:e0197611. [PMID: 29874287 PMCID: PMC5991379 DOI: 10.1371/journal.pone.0197611] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 05/04/2018] [Indexed: 01/10/2023] Open
Abstract
One of the most relevant characteristics of the extant Southern Ocean fauna is its resiliency to survive glacial processes of the Quaternary. These climatic events produced catastrophic habitat reductions and forced some marine benthic species to move, adapt or go extinct. The marine benthic species inhabiting the Antarctic upper continental shelf faced the Quaternary glaciations with different strategies that drastically modified population sizes and thus affected the amount and distribution of intraspecific genetic variation. Here we present new genetic information for the most conspicuous regular sea urchin of the Antarctic continental shelf, Sterechinus neumayeri. We studied the patterns of genetic diversity and structure in this broadcast-spawner across three Antarctic regions: Antarctic Peninsula, the Weddell Sea and Adélie Land in East Antarctica. Genetic analyses based on mitochondrial and nuclear markers suggested that S. neumayeri is a single genetic unit around the Antarctic continent. The species is characterized by low levels of genetic diversity and exhibits a typical star-like haplotype genealogy that supports the hypothesis of a single in situ refugium. Based on two mutation rates standardized for this genus, the Bayesian Skyline plot analyses detected a rapid demographic expansion after the Last Glacial Maximum. We propose a scenario of rapid postglacial expansion and recolonization of Antarctic shallow areas from a less ice-impacted refugium where the species survived the LGM. Considering the patterns of genetic diversity and structure recorded in the species, this refugium was probably located in East Antarctica.
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Affiliation(s)
- Angie Díaz
- Departamento de Zoología, Universida d de Concepción, Barrio Universitario s/n, Concepción, Chile
| | - Karin Gérard
- Facultad de Ciencias, Universidad de Magallanes, Bulnes, Punta Arenas, Chile
- Laboratorio de Ecología Molecular Antártica y Subantártica, Universidad de Magallanes, Punta Arenas, Chile
| | - Claudio González-Wevar
- Laboratorio de Ecología Molecular Antártica y Subantártica, Universidad de Magallanes, Punta Arenas, Chile
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras, Ñuñoa, Santiago, Chile
| | - Claudia Maturana
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras, Ñuñoa, Santiago, Chile
| | - Jean-Pierre Féral
- UMR 7263—IMBE, Station Marine d’Endoume, Institut Méditerranéen de Biodiversité et d’Ecologie Marine et continentale, Chemin de la Batterie des Lions,Marseille, France
| | - Bruno David
- Biogéosciences, UMR CNRS 6282, Université de Bourgogne, boulevard Gabriel, Dijon, France
- Museum National d’Histoire Naturelle, Paris, France
| | - Thomas Saucède
- UMR 7263—IMBE, Station Marine d’Endoume, Institut Méditerranéen de Biodiversité et d’Ecologie Marine et continentale, Chemin de la Batterie des Lions,Marseille, France
| | - Elie Poulin
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras, Ñuñoa, Santiago, Chile
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25
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A new cryptic species of Asteronyx Müller and Troschel, 1842 (Echinodermata: Ophiuroidea), based on molecular phylogeny and morphology, from off Pacific Coast of Japan. ZOOL ANZ 2018. [DOI: 10.1016/j.jcz.2018.03.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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26
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Comparative phylogeography of six red algae along the Antarctic Peninsula: extreme genetic depletion linked to historical bottlenecks and recent expansion. Polar Biol 2018. [DOI: 10.1007/s00300-017-2244-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Adaptation Without Boundaries: Population Genomics in Marine Systems. POPULATION GENOMICS 2018. [DOI: 10.1007/13836_2018_32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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28
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Strugnell JM, Allcock AL, Watts PC. Closely related octopus species show different spatial genetic structures in response to the Antarctic seascape. Ecol Evol 2017; 7:8087-8099. [PMID: 29043058 PMCID: PMC5632630 DOI: 10.1002/ece3.3327] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/18/2017] [Accepted: 07/23/2017] [Indexed: 01/28/2023] Open
Abstract
Determining whether comparable processes drive genetic divergence among marine species is relevant to molecular ecologists and managers alike. Sympatric species with similar life histories might be expected to show comparable patterns of genetic differentiation and a consistent influence of environmental factors in shaping divergence. We used microsatellite loci to quantify genetic differentiation across the Scotia Arc in three species of closely related benthic octopods, Pareledone turqueti, P. charcoti, and Adelieledone polymorpha. The relative importance of environmental factors (latitude, longitude, depth, and temperature) in shaping genetic structure was investigated when significant spatial genetic structure was uncovered. Isolated populations of P. turqueti and A. polymorpha at these species' range margins were genetically different to samples close to mainland Antarctica; however, these species showed different genetic structures at a regional scale. Samples of P. turqueti from the Antarctic Peninsula, Elephant Island, and Signy Island were genetically different, and this divergence was associated primarily with sample collection depth. By contrast, weak or nonsignificant spatial genetic structure was evident across the Antarctic Peninsula, Elephant Island, and Signy Island region for A. polymorpha, and slight associations between population divergence and temperature or depth (and/or longitude) were detected. Pareledone charcoti has a limited geographic range, but exhibited no genetic differentiation between samples from a small region of the Scotia Arc (Elephant Island and the Antarctic Peninsula). Thus, closely related species with similar life history strategies can display contrasting patterns of genetic differentiation depending on spatial scale; moreover, depth may drive genetic divergence in Southern Ocean benthos.
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Affiliation(s)
- Jan M. Strugnell
- Centre for Sustainable Tropical Fisheries and AquacultureMarine Biology and Aquaculture James Cook UniversityTownsvilleQldAustralia
- Department of Ecology, Environment and EvolutionSchool of Life SciencesLa Trobe UniversityMelbourneVic.Australia
| | - A. Louise Allcock
- Ryan Institute and School of Natural SciencesNational University of Ireland GalwayGalwayIreland
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29
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Taylor ML, Roterman CN. Invertebrate population genetics across Earth's largest habitat: The deep-sea floor. Mol Ecol 2017; 26:4872-4896. [PMID: 28833857 DOI: 10.1111/mec.14237] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/16/2017] [Accepted: 06/19/2017] [Indexed: 01/04/2023]
Abstract
Despite the deep sea being the largest habitat on Earth, there are just 77 population genetic studies of invertebrates (115 species) inhabiting non-chemosynthetic ecosystems on the deep-sea floor (below 200 m depth). We review and synthesize the results of these papers. Studies reveal levels of genetic diversity comparable to shallow-water species. Generally, populations at similar depths were well connected over 100s-1,000s km, but studies that sampled across depth ranges reveal population structure at much smaller scales (100s-1,000s m) consistent with isolation by adaptation across environmental gradients, or the existence of physical barriers to connectivity with depth. Few studies were ocean-wide (under 4%), and 48% were Atlantic-focused. There is strong emphasis on megafauna and commercial species with research into meiofauna, "ecosystem engineers" and other ecologically important species lacking. Only nine papers account for ~50% of the planet's surface (depths below 3,500 m). Just two species were studied below 5,000 m, a quarter of Earth's seafloor. Most studies used single-locus mitochondrial genes revealing a common pattern of non-neutrality, consistent with demographic instability or selective sweeps; similar to deep-sea hydrothermal vent fauna. The absence of a clear difference between vent and non-vent could signify that demographic instability is common in the deep sea, or that selective sweeps render single-locus mitochondrial studies demographically uninformative. The number of population genetics studies to date is miniscule in relation to the size of the deep sea. The paucity of studies constrains meta-analyses where broad inferences about deep-sea ecology could be made.
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Affiliation(s)
- M L Taylor
- Department of Zoology, University of Oxford, Oxford, UK
| | - C N Roterman
- Department of Zoology, University of Oxford, Oxford, UK
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30
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Galaska MP, Sands CJ, Santos SR, Mahon AR, Halanych KM. Crossing the Divide: Admixture Across the Antarctic Polar Front Revealed by the Brittle Star Astrotoma agassizii. THE BIOLOGICAL BULLETIN 2017; 232:198-211. [PMID: 28898598 DOI: 10.1086/693460] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The Antarctic Polar Front (APF) is one of the most well-defined and persistent oceanographic features on the planet and serves as a barrier to dispersal between the Southern Ocean and lower latitudes. High levels of endemism in the Southern Ocean have been attributed to this barrier, whereas the accompanying Antarctic Circumpolar Current (ACC) likely promotes west-to-east dispersal. Previous phylogeographic work on the brittle star Astrotoma agassizii Lyman, 1875 based on mitochondrial genes suggested isolation across the APF, even though populations in both South American waters and the Southern Ocean are morphologically indistinguishable. Here, we revisit this finding using a high-resolution 2b-RAD (restriction-site-associated DNA) single-nucleotide polymorphism (SNP)-based approach, in addition to enlarged mitochondrial DNA data sets (16S rDNA, COI, and COII), for comparison to previous work. In total, 955 biallelic SNP loci confirmed the existence of strongly divergent populations on either side of the Drake Passage. Interestingly, genetic admixture was detected between South America and the Southern Ocean in five individuals on both sides of the APF, revealing evidence of recent or ongoing genetic contact. We also identified two differentiated populations on the Patagonian Shelf with six admixed individuals from these two populations. These findings suggest that the APF is a strong but imperfect barrier. Fluctuations in location and strength of the APF and ACC due to climate shifts may have profound consequences for levels of admixture or endemism in this region of the world.
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Verheye ML, Backeljau T, d'Udekem d'Acoz C. Locked in the icehouse: Evolution of an endemic Epimeria (Amphipoda, Crustacea) species flock on the Antarctic shelf. Mol Phylogenet Evol 2017; 114:14-33. [PMID: 28528744 DOI: 10.1016/j.ympev.2017.05.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 05/12/2017] [Accepted: 05/14/2017] [Indexed: 11/24/2022]
Abstract
The Antarctic shelf's marine biodiversity has been greatly influenced by the climatic and glacial history of the region. Extreme temperature changes led to the extinction of some lineages, while others adapted and flourished. The amphipod genus Epimeria is an example of the latter, being particularly diverse in the Antarctic region. By reconstructing a time-calibrated phylogeny based on mitochondrial (COI) and nuclear (28S and H3) markers and including Epimeria species from all oceans, this study provides a temporal and geographical framework for the evolution of Antarctic Epimeria. The monophyly of this genus is not supported by Bayesian Inference, as Antarctic and non-Antarctic Epimeria form two distinct well-supported clades, with Antarctic Epimeria being a sister clade to two stilipedid species. The monophyly of Antarctic Epimeria suggests that this clade evolved in isolation since its origin. While the precise timing of this origin remains unclear, it is inferred that the Antarctic lineage arose from a late Gondwanan ancestor and hence did not colonize the Antarctic region after the continent broke apart from the other fragments of Gondwanaland. The initial diversification of the clade occurred 38.04Ma (95% HPD [48.46Ma; 28.36Ma]) in a cooling environment. Adaptation to cold waters, along with the extinction of cold-intolerant taxa and resulting ecological opportunities, likely led to the successful diversification of Epimeria on the Antarctic shelf. However, there was neither evidence of a rapid lineage diversification early in the clade's history, nor of any shifts in diversification rates induced by glacial cycles. This suggests that a high turnover rate on the repeatedly scoured Antarctic shelf could have masked potential signals of diversification bursts.
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Affiliation(s)
- Marie L Verheye
- Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny, rue Vautier 29, 1000 Brussels, Belgium; Catholic University of Louvain-la-Neuve, Department of Biology, Marine Biology Laboratory, Croix du Sud 3 bte L7.06.04, 1348 Louvain-la-Neuve, Belgium.
| | - Thierry Backeljau
- Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny, rue Vautier 29, 1000 Brussels, Belgium; University of Antwerp, Evolutionary Ecology Group, Universiteitsplein 1, 2160 Antwerp, Belgium
| | - Cédric d'Udekem d'Acoz
- Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny, rue Vautier 29, 1000 Brussels, Belgium
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32
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Miller KJ, Gunasekera RM. A comparison of genetic connectivity in two deep sea corals to examine whether seamounts are isolated islands or stepping stones for dispersal. Sci Rep 2017; 7:46103. [PMID: 28393887 PMCID: PMC5385499 DOI: 10.1038/srep46103] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/10/2017] [Indexed: 11/09/2022] Open
Abstract
Ecological processes in the deep sea are poorly understood due to the logistical constraints of sampling thousands of metres below the ocean’s surface and remote from most land masses. Under such circumstances, genetic data provides unparalleled insight into biological and ecological relationships. We use microsatellite DNA to compare the population structure, reproductive mode and dispersal capacity in two deep sea corals from seamounts in the Southern Ocean. The solitary coral Desmophyllum dianthus has widespread dispersal consistent with its global distribution and resilience to disturbance. In contrast, for the matrix-forming colonial coral Solenosmilia variabilis asexual reproduction is important and the dispersal of sexually produced larvae is negligible, resulting in isolated populations. Interestingly, despite the recognised impacts of fishing on seamount communities, genetic diversity on fished and unfished seamounts was similar for both species, suggesting that evolutionary resilience remains despite reductions in biomass. Our results provide empirical evidence that a group of seamounts can function either as isolated islands or stepping stones for dispersal for different taxa. Furthermore different strategies will be required to protect the two sympatric corals and consequently the recently declared marine reserves in this region may function as a network for D. dianthus, but not for S. variabilis.
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Affiliation(s)
- Karen J Miller
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, The University of Western Australia (MO96), 35 Stirling Hwy, Crawley, Western Australia 6009, Australia
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33
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Mating system and evidence of multiple paternity in the Antarctic brooding sea urchin Abatus agassizii. Polar Biol 2017. [DOI: 10.1007/s00300-016-2001-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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34
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Moon KL, Chown SL, Fraser CI. Reconsidering connectivity in the sub-Antarctic. Biol Rev Camb Philos Soc 2017; 92:2164-2181. [DOI: 10.1111/brv.12327] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 02/09/2017] [Accepted: 02/15/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Katherine L. Moon
- School of Biological Sciences; Monash University; Clayton 3800 Australia
- Fenner School of Environment and Society; Australian National University; Acton 2601 Australia
| | - Steven L. Chown
- School of Biological Sciences; Monash University; Clayton 3800 Australia
| | - Ceridwen I. Fraser
- Fenner School of Environment and Society; Australian National University; Acton 2601 Australia
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35
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Weber AAT, Abi-Rached L, Galtier N, Bernard A, Montoya-Burgos JI, Chenuil A. Positive selection on sperm ion channels in a brooding brittle star: consequence of life-history traits evolution. Mol Ecol 2017; 26:3744-3759. [PMID: 28099777 DOI: 10.1111/mec.14024] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/04/2017] [Accepted: 01/09/2017] [Indexed: 01/12/2023]
Abstract
Closely related species are key models to investigate mechanisms leading to reproductive isolation and early stages of diversification, also at the genomic level. The brittle star cryptic species complex Ophioderma longicauda encompasses the sympatric broadcast-spawning species C3 and the internal brooding species C5. Here, we used de novo transcriptome sequencing and assembly in two closely related species displaying contrasting reproductive modes to compare their genetic diversity and to investigate the role of natural selection in reproductive isolation. We reconstructed 20 146 and 22 123 genes for C3 and C5, respectively, and characterized a set of 12 229 orthologs. Genetic diversity was 1.5-2 times higher in C3 compared to C5, confirming that species with low parental investment display higher levels of genetic diversity. Forty-eight genes were the targets of positive diversifying selection during the evolution of the two species. Notably, two genes (NHE and TetraKCNG) are sperm-specific ion channels involved in sperm motility. Ancestral sequence reconstructions show that natural selection targeted the two genes in the brooding species. This may result from an adaptation to the novel environmental conditions surrounding sperm in the brooding species, either directly affecting sperm or via an increase in male/female conflict. This phenomenon could have promoted prezygotic reproductive isolation between C3 and C5. Finally, the sperm receptors to egg chemoattractants differed between C3 and C5 in the ligand-binding region. We propose that mechanisms of species-specific gamete recognition in brittle stars occur during sperm chemotaxis (sperm attraction towards the eggs), contrary to other marine invertebrates where prezygotic barriers to interspecific hybridization typically occur before sperm-egg fusion.
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Affiliation(s)
- A A-T Weber
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) - CNRS - IRD - UAPV, Aix-Marseille Université, Station Marine d'Endoume, Chemin de la Batterie des Lions, 13007, Marseille, France.,Zoological Institute, University of Basel, Vesalgasse 1, 4051, Basel, Switzerland
| | - L Abi-Rached
- Equipe ATIP, URMITE UM 63 CNRS 7278 IRD 198 Inserm U1095, IHU Méditerranée Infection, Aix-Marseille Université, Marseille, France
| | - N Galtier
- UMR 5554 Institut des Sciences de l'Evolution, CNRS, IRD, EPHE, Université de Montpellier, Place E. Bataillon, 34095, Montpellier, France
| | - A Bernard
- UMR 5554 Institut des Sciences de l'Evolution, CNRS, IRD, EPHE, Université de Montpellier, Place E. Bataillon, 34095, Montpellier, France
| | - J I Montoya-Burgos
- Department of Genetics and Evolution, University of Geneva, 4, Bvd d'Yvoy, 1205, Geneva, Switzerland
| | - A Chenuil
- Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale (IMBE) - CNRS - IRD - UAPV, Aix-Marseille Université, Station Marine d'Endoume, Chemin de la Batterie des Lions, 13007, Marseille, France
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36
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Galaska MP, Sands CJ, Santos SR, Mahon AR, Halanych KM. Geographic structure in the Southern Ocean circumpolar brittle star Ophionotus victoriae (Ophiuridae) revealed from mtDNA and single-nucleotide polymorphism data. Ecol Evol 2016; 7:475-485. [PMID: 28116044 PMCID: PMC5243193 DOI: 10.1002/ece3.2617] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 10/14/2016] [Accepted: 10/20/2016] [Indexed: 01/13/2023] Open
Abstract
Marine systems have traditionally been thought of as “open” with few barriers to gene flow. In particular, many marine organisms in the Southern Ocean purportedly possess circumpolar distributions that have rarely been well verified. Here, we use the highly abundant and endemic Southern Ocean brittle star Ophionotus victoriae to examine genetic structure and determine whether barriers to gene flow have existed around the Antarctic continent. Ophionotus victoriae possesses feeding planktotrophic larvae with presumed high dispersal capability, but a previous study revealed genetic structure along the Antarctic Peninsula. To test the extent of genetic differentiation within O. victoriae, we sampled from the Ross Sea through the eastern Weddell Sea. Whereas two mitochondrial DNA markers (16S rDNA and COI) were employed to allow comparison to earlier work, a 2b‐RAD single‐nucleotide polymorphism (SNP) approach allowed sampling of loci across the genome. Mitochondrial data from 414 individuals suggested three major lineages, but 2b‐RAD data generated 1,999 biallelic loci that identified four geographically distinct groups from 89 samples. Given the greater resolution by SNP data, O. victoriae can be divided into geographically distinct populations likely representing multiple species. Specific historical scenarios that explain current population structure were examined with approximate Bayesian computation (ABC) analyses. Although the Bransfield Strait region shows high diversity possibly due to mixing, our results suggest that within the recent past, dispersal processes due to strong currents such as the Antarctic Circumpolar Current have not overcome genetic subdivision presumably due to historical isolation, questioning the idea of large open circumpolar populations in the Southern Ocean.
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Affiliation(s)
| | - Chester J Sands
- Natural Environment Research Council British Antarctic Survey Cambridge UK
| | - Scott R Santos
- Department of Biological Sciences Auburn University Auburn AL USA
| | - Andrew R Mahon
- Department of Biology Central Michigan University Mount Pleasant MI USA
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37
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Vianna JA, Noll D, Dantas GPM, Petry MV, Barbosa A, González-Acuña D, Le Bohec C, Bonadonna F, Poulin E. Marked phylogeographic structure of Gentoo penguin reveals an ongoing diversification process along the Southern Ocean. Mol Phylogenet Evol 2016; 107:486-498. [PMID: 27940333 DOI: 10.1016/j.ympev.2016.12.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 12/01/2016] [Accepted: 12/06/2016] [Indexed: 11/28/2022]
Abstract
Two main hypotheses have been debated about the biogeography of the Southern Ocean: (1) the Antarctic Polar Front (APF), acting as a barrier between Antarctic and sub-Antarctic provinces, and (2) the Antarctic Circumpolar Current (ACC), promoting gene flow among sub-Antarctic areas. The Gentoo penguin is distributed throughout these two provinces, separated by the APF. We analyzed mtDNA (HVR1) and 12 microsatellite loci of 264 Gentoo penguins, Pygoscelis papua, from 12 colonies spanning from the Western Antarctic Peninsula and the South Shetland Islands (WAP) to the sub-Antarctic Islands (SAI). While low genetic structure was detected among WAP colonies (mtDNA ФST=0.037-0.133; microsatellite FST=0.009-0.063), high differentiation was found between all SAI and WAP populations (mtDNA ФST=0.678-0.930; microsatellite FST=0.110-0.290). These results suggest that contemporary dispersal around the Southern Ocean is very limited or absent. As predicted, the APF appears to be a significant biogeographical boundary for Gentoo penguin populations; however, the ACC does not promote connectivity in this species. Our data suggest demographic expansion in the WAP during the last glacial maximum (LGM, about 20kya), but stability in SAI. Phylogenetic analyses showed a deep divergence between populations from the WAP and those from the SAI. Therefore, taxonomy should be further revised. The Crozet Islands resulted as a basal clade (3.57Mya), followed by the Kerguelen Islands (2.32Mya) as well as a more recent divergence between the Falkland/Malvinas Islands and the WAP (1.27Mya). Historical isolation, local adaptation, and past climate scenarios of those Evolutionarily Significant Units may have led to different potentials to respond to climate changes.
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Affiliation(s)
- Juliana A Vianna
- Pontificia Universidad Católica de Chile, Departamento de Ecosistemas y Medio Ambiente, Vicuña Mackenna 4860, Macul, Santiago, Chile.
| | - Daly Noll
- Pontificia Universidad Católica de Chile, Departamento de Ecosistemas y Medio Ambiente, Vicuña Mackenna 4860, Macul, Santiago, Chile
| | - Gisele P M Dantas
- Pontificia Universidade Católica de Minas Gerais, PPG in Vertebrate Zoology, Belo Horizonte, Brazil
| | - Maria Virginia Petry
- Universidade do Vale do Rio dos Sinos, Laboratório de Ornitologia e Animais Marinhos, Av. Unisinos, 950, São Leopoldo, RS, Brazil
| | - Andrés Barbosa
- Museo Nacional de Ciencias Naturales, Departamento de Ecología Evolutiva, CSIC, C/José Gutiérrez Abascal, 2, 28006 Madrid, Spain
| | - Daniel González-Acuña
- Universidad de Concepción, Departamento de Ciencias Pecuarias, Facultad de Ciencias Veterinarias, Av. Vicente Méndez 595, CP 3780000 Chillán, Chile
| | - Céline Le Bohec
- Université de Strasbourg (UdS), Institut Pluridisciplinaire Hubert Curien, Laboratoire International Associé LIA-647 BioSensib (CSM-CNRS-UdS), 23 rue Becquerel, 67087 Strasbourg Cedex 02, France; Centre National de la Recherche Scientifique (CNRS), UMR 7178, LIA-647 BioSensib, 23 rue Becquerel, 67087 Strasbourg Cedex 02, France; Centre Scientifique de Monaco (CSM), LIA-647 BioSensib, 8 quai Antoine 1er, MC 98000, Monaco
| | - Francesco Bonadonna
- CEFE UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919 route de Mende, 34293 Montpellier cedex 5, France
| | - Elie Poulin
- Instituto de Ecología y Biodiversidad, Departamento de Ciencias Ecológicas, Universidad de Chile, Santiago, Chile
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Andersen JJ, Nelson BJ, Brown JM. EmpPrior: using outside empirical data to inform branch-length priors for Bayesian phylogenetics. BMC Bioinformatics 2016; 17:253. [PMID: 27342194 PMCID: PMC4919878 DOI: 10.1186/s12859-016-1132-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/09/2016] [Indexed: 11/10/2022] Open
Abstract
Background Branch-length parameters are a central component of phylogenetic models and of intrinsic biological interest. Default branch-length priors in some Bayesian phylogenetic software can be unintentionally informative and lead to branch- and tree-length estimates that are unreasonable. Alternatively, priors may be uninformative, but lead to diffuse posterior estimates. Despite the widespread availability of relevant datasets from other groups, biologists rarely leverage outside information to specify branch-length priors that are specific to the analysis they are conducting. Results We developed the software package EmpPrior to facilitate the collection and incorporation of relevant, outside information when setting branch-length priors for phylogenetics. EmpPrior efficiently queries TreeBASE to find data that are similar to focal data, in terms of taxonomic and genetic sampling, and uses them to inform branch-length priors for the focal analysis. EmpPrior consists of two components: EmpPrior-search, written in Java to query TreeBASE, and EmpPrior-fit, written in R to parameterize branch-length distributions. In an example analysis, we show how the use of relevant, outside data is made possible by EmpPrior and improves tree-length estimates from a focal dataset. Conclusion EmpPrior is easy to use, fast, and improves both the accuracy and precision of branch-length estimates in many circumstances. While EmpPrior’s focus is on branch lengths, the strategy it employs could easily be extended to address other prior parameterization problems in phylogenetics.
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Affiliation(s)
- John J Andersen
- Department of Biological Sciences and Museum of Natural Science, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA, 70803, USA.,Present Address: IBM, 11501 Burnet Rd., Austin, TX, 78758, USA
| | - Bradley J Nelson
- Department of Biological Sciences and Museum of Natural Science, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA, 70803, USA.,Present Address: Department of Genome Sciences, University of Washington, Foege Building S-250, Seattle, WA, 98195, USA
| | - Jeremy M Brown
- Department of Biological Sciences and Museum of Natural Science, Louisiana State University, 202 Life Sciences Building, Baton Rouge, LA, 70803, USA.
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González-Wevar CA, Hüne M, Rosenfeld S, Saucède T, Féral JP, Mansilla A, Poulin E. Patterns of genetic diversity and structure in Antarctic and sub-Antarctic Nacella (Patellogastropoda: Nacellidae) species. ACTA ACUST UNITED AC 2016. [DOI: 10.1080/14888386.2016.1181573] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Claudio A. González-Wevar
- GAIA Antártica/Departamento de Recursos Naturales, Universidad de Magallanes, Bulnes 01890, Punta Arenas, Chile
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras #3425, Ñuñoa, Santiago, Chile
| | - Mathias Hüne
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras #3425, Ñuñoa, Santiago, Chile
- Fundación Ictiológica, Pedro de Valdivia 2086, Departamento 406, Providencia, Santiago, Chile
| | - Sebastián Rosenfeld
- GAIA Antártica/Departamento de Recursos Naturales, Universidad de Magallanes, Bulnes 01890, Punta Arenas, Chile
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras #3425, Ñuñoa, Santiago, Chile
| | - Thomas Saucède
- Biogéosciences, Université de Bourgogne, UMR CNRS 6282, Dijon, France
| | - Jean-Pierre Féral
- Institut Méditerrané de Biodiversité et d’Ecologie marine et continentale, Aix Marseille Université-CNR-IRD-Avignon Université, Marseille, France
| | - Andrés Mansilla
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras #3425, Ñuñoa, Santiago, Chile
- Departamento de Recursos Naturales, Universidad de Magallanes, Avenida Bulnes 01890, XII Región de Magallanes y de la Antártica Chilena, Punta Arenas, Chile
| | - Elie Poulin
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras #3425, Ñuñoa, Santiago, Chile
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Verheye ML, Backeljau T, d’Udekem d’Acoz C. Looking beneath the tip of the iceberg: diversification of the genus Epimeria on the Antarctic shelf (Crustacea, Amphipoda). Polar Biol 2016. [DOI: 10.1007/s00300-016-1910-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Dueñas LF, Tracey DM, Crawford AJ, Wilke T, Alderslade P, Sánchez JA. The Antarctic Circumpolar Current as a diversification trigger for deep-sea octocorals. BMC Evol Biol 2016; 16:2. [PMID: 26727928 PMCID: PMC4700699 DOI: 10.1186/s12862-015-0574-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 12/19/2015] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Antarctica is surrounded by the Antarctic Circumpolar Current (ACC), the largest and strongest current in the world. Despite its potential importance for shaping biogeographical patterns, the distribution and connectivity of deep-sea populations across the ACC remain poorly understood. In this study we conducted the first assessment of phylogeographical patterns in deep-sea octocorals in the South Pacific and Southern Ocean, specifically a group of closely related bottlebrush octocorals (Primnoidae: Tokoprymno and Thourella), as a test case to study the effect of the ACC on the population structure of brooding species. We assessed the degree to which the ACC constitutes a barrier to gene flow between northern and southern populations and whether the onset of diversification of these corals coincides with the origin of the ACC (Oligocene-Miocene boundary). RESULTS Based on DNA sequences of two nuclear genes from 80 individuals and a combination of phylogeographic model-testing approaches we found a phylogenetic break corresponding to the spatial occurrence of the ACC. We also found significant genetic structure among our four regional populations. However, we uncovered shared haplotypes among certain population pairs, suggesting long-distance, asymmetrical migration. Our divergence time analyses indicated that the separation of amphi-ACC populations took place during the Middle Miocene around 12.6 million years ago, i.e., after the formation of the ACC. CONCLUSION We suggest that the ACC constitutes a semi-permeable barrier to these deep-sea octocorals capable of separating and structuring populations, while allowing short periods of gene flow. The fluctuations in latitudinal positioning of the ACC during the Miocene likely contributed to the diversification of these octocorals. Additionally, we provide evidence that the populations from each of our four sampling regions could actually constitute different species.
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Affiliation(s)
- Luisa F Dueñas
- Department of Biological Sciences, Universidad de los Andes, A.A. 4976, Bogotá, Colombia.
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany.
| | - Dianne M Tracey
- National Institute of Water and Atmospheric Research-NIWA, Wellington, New Zealand.
| | - Andrew J Crawford
- Department of Biological Sciences, Universidad de los Andes, A.A. 4976, Bogotá, Colombia.
- Smithsonian Tropical Research Institute, Apartado, 0843-03092, Panama City, Republic of Panama.
| | - Thomas Wilke
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany.
| | - Phil Alderslade
- CSIRO Marine and Atmospheric Research, PO Box 1538, Hobart, Tasmania, 7001, Australia.
| | - Juan A Sánchez
- Department of Biological Sciences, Universidad de los Andes, A.A. 4976, Bogotá, Colombia.
- Department of Animal Ecology & Systematics, Justus Liebig University, Giessen, Germany.
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Steel DJ, Stewart BG, Trewick SA, Wallis GP. Fiord populations ofAstrobrachion constrictum(Ophiuroidea: Asteroschematidae) show little genetic differentiation for mitochondrial DNA. NEW ZEALAND JOURNAL OF ZOOLOGY 2015. [DOI: 10.1080/03014223.2015.1059863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Abstract
Abstract
Benthic foraminifera are a major component of the Antarctic biota. Coastal foraminiferal morphospecies are widely distributed in Antarctic waters. The question is whether these morphotypes are genetically identical or, rather, they represent a cohort of cryptic species. Here, we compared genetically nine benthic foraminiferal morphospecies from Admiralty Bay (South Shetlands) and the western Ross Sea (McMurdo Sound, Terra Nova Bay), separated by a distance of ~4500 km. Additionally, for three of these morphospecies, we included specimens from Rothera (Marguerite Bay), which is located between the two main areas of interest. Our study, based on SSU and ITS rDNA sequence data, shows that all examined morphospecies share the same genotypes despite the presence of considerable intra-individual genetic variability.
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Riesgo A, Taboada S, Avila C. Evolutionary patterns in Antarctic marine invertebrates: an update on molecular studies. Mar Genomics 2015; 23:1-13. [PMID: 26228311 DOI: 10.1016/j.margen.2015.07.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 07/17/2015] [Accepted: 07/17/2015] [Indexed: 01/08/2023]
Affiliation(s)
- Ana Riesgo
- Department of Animal Biology and Biodiversity Research Institute (IrBIO), Faculty of Biology, Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Catalonia, Spain.
| | - Sergi Taboada
- Department of Animal Biology and Biodiversity Research Institute (IrBIO), Faculty of Biology, Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Catalonia, Spain
| | - Conxita Avila
- Department of Animal Biology and Biodiversity Research Institute (IrBIO), Faculty of Biology, Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Catalonia, Spain
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Chown SL, Clarke A, Fraser CI, Cary SC, Moon KL, McGeoch MA. The changing form of Antarctic biodiversity. Nature 2015; 522:431-8. [DOI: 10.1038/nature14505] [Citation(s) in RCA: 202] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 04/24/2015] [Indexed: 11/09/2022]
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González-Wevar CA, Chown SL, Morley S, Coria N, Saucéde T, Poulin E. Out of Antarctica: quaternary colonization of sub-Antarctic Marion Island by the limpet genus Nacella (Patellogastropoda: Nacellidae). Polar Biol 2014. [DOI: 10.1007/s00300-014-1620-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Weber AAT, Stöhr S, Chenuil A. Genetic data, reproduction season and reproductive strategy data support the existence of biological species in Ophioderma longicauda. C R Biol 2014; 337:553-60. [PMID: 25282170 DOI: 10.1016/j.crvi.2014.07.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 07/23/2014] [Accepted: 07/24/2014] [Indexed: 11/30/2022]
Abstract
Cryptic species are numerous in the marine environment. The brittle star Ophioderma longicauda is composed of six mitochondrial lineages, encompassing brooders, which form a monophyletic group, and broadcasters, from which the brooders are derived. To clarify the species limits within O. longicauda, we compared the reproductive status of the sympatric lineages L1 and L3 (defined after sequencing a portion of the mitochondrial gene COI) during the month of May in Greece. In addition, we genotyped a nuclear marker, intron i51. Each L3 female was brooding, whereas all L1 specimens displayed full gonads, suggesting temporal pre-zygotic isolation between brooders and broadcasters. Statistical differences were found among lineages in morphology and bathymetric distribution. Finally, the intron i51 was polymorphic in L1 (60 individuals), but monomorphic in L3 (109 individuals), confirming the absence of gene flow between brooders and broadcasters. In conclusion, the broadcasting lineage L1 and the brooding lineage L3 are different biological species.
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Affiliation(s)
- Alexandra Anh-Thu Weber
- Aix-Marseille Université, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), CNRS - IRD - UAPV, station marine d'Endoume, chemin de la Batterie-des-Lions, 13007 Marseille, France.
| | - Sabine Stöhr
- Department of Zoology, Swedish Museum of Natural History, Box 50007, 10405 Stockholm, Sweden
| | - Anne Chenuil
- Aix-Marseille Université, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), CNRS - IRD - UAPV, station marine d'Endoume, chemin de la Batterie-des-Lions, 13007 Marseille, France
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Douglass LL, Turner J, Grantham HS, Kaiser S, Constable A, Nicoll R, Raymond B, Post A, Brandt A, Beaver D. A hierarchical classification of benthic biodiversity and assessment of protected areas in the Southern Ocean. PLoS One 2014; 9:e100551. [PMID: 25032993 PMCID: PMC4102490 DOI: 10.1371/journal.pone.0100551] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 05/27/2014] [Indexed: 11/18/2022] Open
Abstract
An international effort is underway to establish a representative system of marine protected areas (MPAs) in the Southern Ocean to help provide for the long-term conservation of marine biodiversity in the region. Important to this undertaking is knowledge of the distribution of benthic assemblages. Here, our aim is to identify the areas where benthic marine assemblages are likely to differ from each other in the Southern Ocean including near-shore Antarctica. We achieve this by using a hierarchical spatial classification of ecoregions, bathomes and environmental types. Ecoregions are defined according to available data on biogeographic patterns and environmental drivers on dispersal. Bathomes are identified according to depth strata defined by species distributions. Environmental types are uniquely classified according to the geomorphic features found within the bathomes in each ecoregion. We identified 23 ecoregions and nine bathomes. From a set of 28 types of geomorphic features of the seabed, 562 unique environmental types were classified for the Southern Ocean. We applied the environmental types as surrogates of different assemblages of biodiversity to assess the representativeness of existing MPAs. We found that 12 ecoregions are not represented in MPAs and that no ecoregion has their full range of environmental types represented in MPAs. Current MPA planning processes, if implemented, will substantially increase the representation of environmental types particularly within 8 ecoregions. To meet internationally agreed conservation goals, additional MPAs will be needed. To assist with this process, we identified 107 spatially restricted environmental types, which should be considered for inclusion in future MPAs. Detailed supplementary data including a spatial dataset are provided.
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Affiliation(s)
- Lucinda L. Douglass
- Centre for Biodiversity and Conservation Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
- Centre for Conservation Geography, Sydney, New South Wales, Australia
- * E-mail:
| | - Joel Turner
- Centre for Conservation Geography, Sydney, New South Wales, Australia
| | - Hedley S. Grantham
- Centre for Biodiversity and Conservation Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
- Betty and Gordon Moore Centre for Science and Oceans, Conservation International, Arlington, Virginia, United States of America
| | - Stefanie Kaiser
- Biocentre Grindel and Zoological Museum, University of Hamburg, Hamburg, Germany
- German Centre for Marine Biodiversity Research, Wilhelmshaven, Germany
| | - Andrew Constable
- Australian Antarctic Division, Department of the Environment, Australian Government, Kingston, Tasmania, Australia
- Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - Rob Nicoll
- WWF Australia, Ultimo, New South Wales, Australia
| | - Ben Raymond
- Australian Antarctic Division, Department of the Environment, Australian Government, Kingston, Tasmania, Australia
- Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - Alexandra Post
- Marine and Coastal Environment Group, Geoscience Australia, Canberra, Australian Capital Territory, Australia
| | - Angelika Brandt
- Biocentre Grindel and Zoological Museum, University of Hamburg, Hamburg, Germany
| | - Daniel Beaver
- Centre for Biodiversity and Conservation Science, School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
- Centre for Conservation Geography, Sydney, New South Wales, Australia
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Convey P, Chown SL, Clarke A, Barnes DKA, Bokhorst S, Cummings V, Ducklow HW, Frati F, Green TGA, Gordon S, Griffiths HJ, Howard-Williams C, Huiskes AHL, Laybourn-Parry J, Lyons WB, McMinn A, Morley SA, Peck LS, Quesada A, Robinson SA, Schiaparelli S, Wall DH. The spatial structure of Antarctic biodiversity. ECOL MONOGR 2014. [DOI: 10.1890/12-2216.1] [Citation(s) in RCA: 232] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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