1
|
Bandara RMWJ, Curchitser E, Pinsky ML. The importance of oxygen for explaining rapid shifts in a marine fish. Glob Chang Biol 2024; 30:e17008. [PMID: 37943111 DOI: 10.1111/gcb.17008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 09/07/2023] [Accepted: 09/27/2023] [Indexed: 11/10/2023]
Abstract
Large-scale shifts in marine species biogeography have been a notable impact of climate change. An effective explanation of what drives these species shifts, as well as accurate predictions of where they might move, is crucial to effectively managing these natural resources and conserving biodiversity. While temperature has been implicated as a major driver of these shifts, physiological processes suggest that oxygen, prey, and other factors should also play important roles. We expanded upon previous temperature-based distribution models by testing whether oxygen, food web productivity, salinity, and scope for metabolic activity (the Metabolic Index) better explained the changing biogeography of Black Sea Bass (Centropristis striata) in the Northeast US. This species has been expanding further north over the past 15 years. We found that oxygen improved model performance beyond a simple consideration of temperature (ΔAIC = 799, ΔTSS = 0.015), with additional contributions from prey and salinity. However, the Metabolic Index did not substantially increase model performance relative to temperature and oxygen (ΔAIC = 0.63, ΔTSS = 0.0002). Marine species are sensitive to oxygen, and we encourage researchers to use ocean biogeochemical hindcast and forecast products to better understand marine biogeographic changes.
Collapse
Affiliation(s)
| | - Enrique Curchitser
- Department of Environmental Sciences, Rutgers University, New Brunswick, New Jersey, USA
| | - Malin L Pinsky
- Graduate Program in Ecology and Evolution, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| |
Collapse
|
2
|
Sinclair EA, Hovey RK, Krauss SL, Anthony JM, Waycott M, Kendrick GA. Historic and contemporary biogeographic perspectives on range-wide spatial genetic structure in a widespread seagrass. Ecol Evol 2023; 13:e9900. [PMID: 36950371 PMCID: PMC10025079 DOI: 10.1002/ece3.9900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/26/2023] [Indexed: 03/22/2023] Open
Abstract
Historical and contemporary processes drive spatial patterns of genetic diversity. These include climate-driven range shifts and gene flow mediated by biogeographical influences on dispersal. Assessments that integrate these drivers are uncommon, but critical for testing biogeographic hypotheses. Here, we characterize intraspecific genetic diversity and spatial structure across the entire distribution of a temperate seagrass to test marine biogeographic concepts for southern Australia. Predictive modeling was used to contrast the current Posidonia australis distribution to its historical distribution during the Last Glacial Maximum (LGM). Spatial genetic structure was estimated for 44 sampled meadows from across the geographical range of the species using nine microsatellite loci. Historical and contemporary distributions were similar, with the exception of the Bass Strait. Genetic clustering was consistent with the three currently recognized biogeographic provinces and largely consistent with the finer-scale IMCRA bioregions. Discrepancies were found within the Flindersian province and southwest IMCRA bioregion, while two regions of admixture coincided with transitional IMCRA bioregions. Clonal diversity was highly variable but positively associated with latitude. Genetic differentiation among meadows was significantly associated with oceanographic distance. Our approach suggests how shared seascape drivers have influenced the capacity of P. australis to effectively track sea level changes associated with natural climate cycles over millennia, and in particular, the recolonization of meadows across the Continental Shelf following the LGM. Genetic structure associated with IMCRA bioregions reflects the presence of stable biogeographic barriers, such as oceanic upwellings. This study highlights the importance of biogeography to infer the role of historical drivers in shaping extant diversity and structure.
Collapse
Affiliation(s)
- Elizabeth A. Sinclair
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Oceans Institute, University of Western AustraliaCrawleyWestern AustraliaAustralia
- Kings Park Science, Department of Biodiversity Conservation and AttractionsKings ParkWestern AustraliaAustralia
| | - Renae K. Hovey
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Oceans Institute, University of Western AustraliaCrawleyWestern AustraliaAustralia
| | - Siegfried L. Krauss
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Kings Park Science, Department of Biodiversity Conservation and AttractionsKings ParkWestern AustraliaAustralia
| | - Janet M. Anthony
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Kings Park Science, Department of Biodiversity Conservation and AttractionsKings ParkWestern AustraliaAustralia
| | - Michelle Waycott
- School of Biological SciencesUniversity of Adelaide and State Herbarium of South AustraliaAdelaideSouth AustraliaAustralia
| | - Gary A. Kendrick
- School of Biological SciencesUniversity of Western AustraliaCrawleyWestern AustraliaAustralia
- Oceans Institute, University of Western AustraliaCrawleyWestern AustraliaAustralia
| |
Collapse
|
3
|
Bock N, Cornec M, Claustre H, Duhamel S. Biogeographical Classification of the Global Ocean From BGC-Argo Floats. Global Biogeochem Cycles 2022; 36:e2021GB007233. [PMID: 35865129 PMCID: PMC9287098 DOI: 10.1029/2021gb007233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 04/19/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Biogeographical classifications of the global ocean generalize spatiotemporal trends in species or biomass distributions across discrete ocean biomes or provinces. These classifications are generally based on a combination of remote-sensed proxies of phytoplankton biomass and global climatologies of biogeochemical or physical parameters. However, these approaches are limited in their capacity to account for subsurface variability in these parameters. The deployment of autonomous profiling floats in the Biogeochemical Argo network over the last decade has greatly increased global coverage of subsurface measurements of bio-optical proxies for phytoplankton biomass and physiology. In this study, we used empirical orthogonal function analysis to identify the main components of variability in a global data set of 422 annual time series of Chlorophyll a fluorescence and optical backscatter profiles. Applying cluster analysis to these results, we identified six biomes within the global ocean: two high-latitude biomes capturing summer bloom dynamics in the North Atlantic and Southern Ocean and four mid- and low-latitude biomes characterized by variability in the depth and frequency of deep chlorophyll maximum formation. We report the distribution of these biomes along with associated trends in biogeochemical and physicochemical environmental parameters. Our results demonstrate light and nutrients to explain most variability in phytoplankton distributions for all biomes, while highlighting a global inverse relationship between particle stocks in the euphotic zone and transfer efficiency into the mesopelagic zone. In addition to partitioning seasonal variability in vertical phytoplankton distributions at the global scale, our results provide a potentially novel biogeographical classification of the global ocean.
Collapse
Affiliation(s)
- Nicholas Bock
- Lamont‐Doherty Earth ObservatoryColumbia UniversityPalisadesNYUSA
| | - Marin Cornec
- CNRS & Sorbonne UniversitéLaboratoire d'Océanographie de VillefrancheLOVVillefranche‐sur‐MerFrance
- Now at School of OceanographyUniversity of WashingtonSeattleWAUSA
| | - Hervé Claustre
- CNRS & Sorbonne UniversitéLaboratoire d'Océanographie de VillefrancheLOVVillefranche‐sur‐MerFrance
| | - Solange Duhamel
- Lamont‐Doherty Earth ObservatoryColumbia UniversityPalisadesNYUSA
- Department of Molecular and Cellular BiologyUniversity of ArizonaTucsonAZUSA
| |
Collapse
|
4
|
Lagourgue L, Leliaert F, Payri CE. Historical biogeographical analysis of the Udoteaceae (Bryopsidales, Chlorophyta) elucidates origins of high species diversity in the Central Indo-Pacific, Western Indian Ocean and Greater Caribbean regions. Mol Phylogenet Evol 2022; 169:107412. [PMID: 35031470 DOI: 10.1016/j.ympev.2022.107412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 11/19/2021] [Accepted: 12/07/2021] [Indexed: 11/28/2022]
Abstract
There is a growing interest in elucidating the biogeographical processes underlying biodiversity patterns of seaweeds, with recent studies largely focusing on red and brown macroalgae. This study focuses on the siphonous green algal family Udoteaceae, which is diverse and globally distributed in tropical to warm-temperate seas, and includes species that form important components of tropical reefs. We explored the historical processes that have shaped current biodiversity patterns in the family by analyzing a comprehensive dataset of 568 specimens sampled across its geographical range, and including 45 species, corresponding to 59% of the known diversity. Historical biogeographical analysis was based on a three-locus time-calibrated phylogeny, and probabilistic modeling of geographical range evolution. Many species were found to have restricted ranges, indicative of low dispersal capacity. Our analysis points toward a Western Tethys origin and early diversification of the Udoteaceae in the Triassic period. Three centers of diversity were identified, which are, in order of highest species richness, the Central Indo-Pacific, the Western Indian Ocean, and the Greater Caribbean. Different drivers have likely played a role in shaping these diversity centres. Species richness in the Central Indo-Pacific likely resulted from speciation within the region, as well as recolonization from neighbouring regions, and overlap of some wider ranged species, corroborating the "biodiversity feedback" model. Species richness in the Western Indian Ocean can be explained by ancient and more recent diversification within the region, and dispersal from the Central Indo-Pacific. The Greater Caribbean region was colonized more recently, followed by diversification within the region.
Collapse
Affiliation(s)
- Laura Lagourgue
- Sorbonne Universités, UPMC Univ Paris 06, IFD, 4 Place Jussieu, 75252 Paris Cedex 05, France; UMR ENTROPIE (IRD, UR, UNC, CNRS, IFREMER), Institut de Recherche pour le Développement, B.P. A5 Nouméa Cedex, Nouvelle-Calédonie, 98848, France.
| | | | - Claude E Payri
- UMR ENTROPIE (IRD, UR, UNC, CNRS, IFREMER), Institut de Recherche pour le Développement, B.P. A5 Nouméa Cedex, Nouvelle-Calédonie, 98848, France
| |
Collapse
|
5
|
Parvizi E, Dutoit L, Fraser CI, Craw D, Waters JM. Concordant phylogeographic responses to large-scale coastal disturbance in intertidal macroalgae and their epibiota. Mol Ecol 2021; 31:646-657. [PMID: 34695264 DOI: 10.1111/mec.16245] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 10/13/2021] [Accepted: 10/20/2021] [Indexed: 01/05/2023]
Abstract
Major ecological disturbance events can provide opportunities to assess multispecies responses to upheaval. In particular, catastrophic disturbances that regionally extirpate habitat-forming species can potentially influence the genetic diversity of large numbers of codistributed taxa. However, due to the rarity of such disturbance events over ecological timeframes, the genetic dynamics of multispecies recolonization processes have remained little understood. Here, we use single nucleotide polymorphism (SNP) data from multiple coastal species to track the dynamics of cocolonization events in response to ancient earthquake disturbance in southern New Zealand. Specifically, we use a comparative phylogeographic approach to understand the extent to which epifauna (with varying ecological associations with their macroalgal hosts) share comparable spatial and temporal recolonization patterns. Our study reveals concordant disturbance-related phylogeographic breaks in two intertidal macroalgal species along with two associated epibiotic species (a chiton and an isopod). By contrast, two codistributed species, one of which is an epibiotic amphipod and the other a subtidal macroalga, show few, if any, genetic effects of palaeoseismic coastal uplift. Phylogeographic model selection reveals similar post-uplift recolonization routes for the epibiotic chiton and isopod and their macroalgal hosts. Additionally, codemographic analyses support synchronous population expansions of these four phylogeographically similar taxa. Our findings indicate that coastal paleoseismic activity has driven concordant impacts on multiple codistributed species, with concerted recolonization events probably facilitated by macroalgal rafting. These results highlight that high-resolution comparative genomic data can help reconstruct concerted multispecies responses to recent ecological disturbance.
Collapse
Affiliation(s)
- Elahe Parvizi
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Ludovic Dutoit
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Ceridwen I Fraser
- Department of Marine Science, University of Otago, Dunedin, New Zealand
| | - Dave Craw
- Department of Geology, University of Otago, Dunedin, New Zealand
| | | |
Collapse
|
6
|
Freestone AL, Torchin ME, Jurgens LJ, Bonfim M, López DP, Repetto MF, Schlöder C, Sewall BJ, Ruiz GM. Stronger predation intensity and impact on prey communities in the tropics. Ecology 2021; 102:e03428. [PMID: 34105781 DOI: 10.1002/ecy.3428] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 12/21/2020] [Accepted: 02/05/2021] [Indexed: 11/06/2022]
Abstract
The hypothesis that biotic interactions strengthen toward lower latitudes provides a framework for linking community-scale processes with the macroecological scales that define our biosphere. Despite the importance of this hypothesis for understanding community assembly and ecosystem functioning, the extent to which interaction strength varies across latitude and the effects of this variation on natural communities remain unresolved. Predation in particular is central to ecological and evolutionary dynamics across the globe, yet very few studies explore both community-scale causes and outcomes of predation across latitude. Here we expand beyond prior studies to examine two important components of predation strength: intensity of predation (including multiple dimensions of the predator guild) and impact on prey community biomass and structure, providing one of the most comprehensive examinations of predator-prey interactions across latitude. Using standardized experiments, we tested the hypothesis that predation intensity and impact on prey communities were stronger at lower latitudes. We further assessed prey recruitment to evaluate the potential for this process to mediate predation effects. We used sessile marine invertebrate communities and their fish predators in nearshore environments as a model system, with experiments conducted at 12 sites in four regions spanning the tropics to the subarctic. Our results show clear support for an increase in both predation intensity and impact at lower relative to higher latitudes. The predator guild was more diverse at low latitudes, with higher predation rates, longer interaction durations, and larger predator body sizes, suggesting stronger predation intensity in the tropics. Predation also reduced prey biomass and altered prey composition at low latitudes, with no effects at high latitudes. Although recruitment rates were up to three orders of magnitude higher in the tropics than the subarctic, prey replacement through this process was insufficient to dampen completely the strong impacts of predators in the tropics. Our study provides a novel perspective on the biotic interaction hypothesis, suggesting that multiple components of the predator community likely contribute to predation intensity at low latitudes, with important consequences for the structure of prey communities.
Collapse
Affiliation(s)
- Amy L Freestone
- Department of Biology, Temple University, Philadelphia, Pennsylvania, 19122, USA.,Smithsonian Environmental Research Center, Edgewater, Maryland, 21037-0028, USA.,Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Ancon, Panama
| | - Mark E Torchin
- Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Ancon, Panama
| | - Laura J Jurgens
- Department of Biology, Temple University, Philadelphia, Pennsylvania, 19122, USA.,Smithsonian Environmental Research Center, Edgewater, Maryland, 21037-0028, USA.,Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Ancon, Panama
| | - Mariana Bonfim
- Department of Biology, Temple University, Philadelphia, Pennsylvania, 19122, USA
| | - Diana P López
- Department of Biology, Temple University, Philadelphia, Pennsylvania, 19122, USA
| | - Michele F Repetto
- Department of Biology, Temple University, Philadelphia, Pennsylvania, 19122, USA
| | - Carmen Schlöder
- Smithsonian Tropical Research Institute, Apartado, 0843-03092, Balboa, Ancon, Panama
| | - Brent J Sewall
- Department of Biology, Temple University, Philadelphia, Pennsylvania, 19122, USA
| | - Gregory M Ruiz
- Smithsonian Environmental Research Center, Edgewater, Maryland, 21037-0028, USA
| |
Collapse
|
7
|
Torquato F, Range P, Ben‐Hamadou R, Sigsgaard EE, Thomsen PF, Riera R, Berumen ML, Burt JA, Feary DA, Marshell A, D'Agostino D, DiBattista JD, Møller PR. Consequences of marine barriers for genetic diversity of the coral-specialist yellowbar angelfish from the Northwestern Indian Ocean. Ecol Evol 2019; 9:11215-11226. [PMID: 31641466 PMCID: PMC6802022 DOI: 10.1002/ece3.5622] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/30/2019] [Accepted: 08/07/2019] [Indexed: 02/06/2023] Open
Abstract
Ocean circulation, geological history, geographic distance, and seascape heterogeneity play an important role in phylogeography of coral-dependent fishes. Here, we investigate potential genetic population structure within the yellowbar angelfish (Pomacanthus maculosus) across the Northwestern Indian Ocean (NIO). We then discuss our results with respect to the above abiotic features in order to understand the contemporary distribution of genetic diversity of the species. To do so, restriction site-associated DNA sequencing (RAD-seq) was utilized to carry out population genetic analyses on P. maculosus sampled throughout the species' distributional range. First, genetic data were correlated to geographic and environmental distances, and tested for isolation-by-distance and isolation-by-environment, respectively, by applying the Mantel test. Secondly, we used distance-based and model-based methods for clustering genetic data. Our results suggest the presence of two putative barriers to dispersal; one off the southern coast of the Arabian Peninsula and the other off northern Somalia, which together create three genetic subdivisions of P. maculosus within the NIO. Around the Arabian Peninsula, one genetic cluster was associated with the Red Sea and the adjacent Gulf of Aden in the west, and another cluster was associated with the Arabian Gulf and the Sea of Oman in the east. Individuals sampled in Kenya represented a third genetic cluster. The geographic locations of genetic discontinuities observed between genetic subdivisions coincide with the presence of substantial upwelling systems, as well as habitat discontinuity. Our findings shed light on the origin and maintenance of genetic patterns in a common coral reef fish inhabiting the NIO, and reinforce the hypothesis that the evolution of marine fish species in this region has likely been shaped by multiple vicariance events.
Collapse
Affiliation(s)
- Felipe Torquato
- Section for Evolutionary GenomicsNatural History Museum of DenmarkUniversity of CopenhagenCopenhagenDenmark
| | - Pedro Range
- Environmental Science CenterQatar UniversityDohaQatar
| | - Radhouane Ben‐Hamadou
- Department Biological and Environmental ScienceCollege of Arts and SciencesQatar UniversityDohaQatar
| | - Eva E. Sigsgaard
- Section for Evolutionary GenomicsNatural History Museum of DenmarkUniversity of CopenhagenCopenhagenDenmark
- Department of BioscienceUniversity of AarhusAarhusDenmark
| | | | - Rodrigo Riera
- Departamento de EcologíaFacultad de CienciasUniversidad Católica de la Santísima ConcepciónConcepciónChile
| | - Michael L. Berumen
- Division of Biological and Environmental Sciences and EngineeringRed Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - John A. Burt
- Center for Genomics and Systems BiologyNew York University Abu DhabiAbu DhabiUAE
| | | | - Alyssa Marshell
- Marine Ecology Lab OmanDepartment of Marine Science and FisheriesCollege of Agriculture and Marine ScienceSultan Qaboos UniversityMuscatOman
| | | | - Joseph D. DiBattista
- Division of Biological and Environmental Sciences and EngineeringRed Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
- School of Molecular and Life SciencesCurtin UniversityPerthWAAustralia
- Australian Museum Research InstituteAustralian MuseumSydneyNSWAustralia
| | - Peter R. Møller
- Section for Evolutionary GenomicsNatural History Museum of DenmarkUniversity of CopenhagenCopenhagenDenmark
| |
Collapse
|
8
|
He S, Robitzch V, Hobbs JA, Travers MJ, Lozano‐Cortés D, Berumen ML, DiBattista JD. An examination of introgression and incomplete lineage sorting among three closely related species of chocolate-dipped damselfish (genus: Chromis). Ecol Evol 2019; 9:5468-5478. [PMID: 31110695 PMCID: PMC6509375 DOI: 10.1002/ece3.5142] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 03/15/2019] [Indexed: 11/11/2022] Open
Abstract
AIM To determine the impact of ecological and environmental histories on the evolution of coral reef damselfishes at two adjacent marine biogeographic suture zones. LOCATION Indo-West Pacific, notably including two suture zones: Socotra and Christmas and Cocos/Keeling Islands. TAXON Chromis dimidiata, Chromis margaritifer, and Chromis fieldi. METHODS We utilized a combination of nuclear and mitochondrial genetic markers in addition to visual abundance survey data of these fishes. RESULTS Despite genetic patterns consistent with incomplete lineage sorting and relatively low genetic differentiation among the three studied Chromis species, there is evidence of hybridization between C. margaritifer and C. fieldi at Christmas Island based on molecular and visual identification. Introgression appears to be spreading westwards to other C. fieldi populations based on COI haplotype comparison. Moreover, the genetic distance between C. margaritifer and C. fieldi suggests that Pleistocene sea-level fluctuations may have contributed to allopatric divergence and secondary contact between these two closely related species. MAIN CONCLUSIONS Our study highlights that evolutionary processes in coral reef fishes operate differently between suture zones, possibly due to different ecological and environmental predispositions regulating secondary contact of sister species. While secondary contact likely led to hybridization and introgression at Christmas and Cocos/Keeling Islands, none of those processes seem present at Socotra for the chocolate-dipped damselfish. This difference is likely due to an environmental barrier caused by hydrodynamic regimes in the Gulf of Aden.
Collapse
Affiliation(s)
- Song He
- Division of Biological and Environmental Science and Engineering, Red Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - Vanessa Robitzch
- Division of Biological and Environmental Science and Engineering, Red Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - Jean‐Paul A. Hobbs
- School of Molecular and Life SciencesCurtin UniversityPerthWestern AustraliaAustralia
| | - Michael J. Travers
- Australian Institute of Marine ScienceIndian Oceans Marine Research CentreCrawleyWestern AustraliaAustralia
| | - Diego Lozano‐Cortés
- Division of Biological and Environmental Science and Engineering, Red Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - Michael L. Berumen
- Division of Biological and Environmental Science and Engineering, Red Sea Research CenterKing Abdullah University of Science and TechnologyThuwalSaudi Arabia
| | - Joseph D. DiBattista
- School of Molecular and Life SciencesCurtin UniversityPerthWestern AustraliaAustralia
- Australian Museum Research InstituteAustralian MuseumSydneyNew South WalesAustralia
| |
Collapse
|
9
|
Teske PR, Sandoval-Castillo J, Golla TR, Emami-Khoyi A, Tine M, von der Heyden S, Beheregaray LB. Thermal selection as a driver of marine ecological speciation. Proc Biol Sci 2019; 286:20182023. [PMID: 30963923 PMCID: PMC6408613 DOI: 10.1098/rspb.2018.2023] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/11/2019] [Indexed: 12/19/2022] Open
Abstract
Intraspecific genetic structure in widely distributed marine species often mirrors the boundaries between temperature-defined bioregions. This suggests that the same thermal gradients that maintain distinct species assemblages also drive the evolution of new biodiversity. Ecological speciation scenarios are often invoked to explain such patterns, but the fact that adaptation is usually only identified when phylogenetic splits are already evident makes it impossible to rule out the alternative scenario of allopatric speciation with subsequent adaptation. We integrated large-scale genomic and environmental datasets along one of the world's best-defined marine thermal gradients (the South African coastline) to test the hypothesis that incipient ecological speciation is a result of divergence linked to the thermal environment. We identified temperature-associated gene regions in a coastal fish species that is spatially homogeneous throughout several temperature-defined biogeographic regions based on selectively neutral markers. Based on these gene regions, the species is divided into geographically distinct regional populations. Importantly, the ranges of these populations are delimited by the same ecological boundaries that define distinct infraspecific genetic lineages in co-distributed marine species, and biogeographic disjunctions in species assemblages. Our results indicate that temperature-mediated selection represents an early stage of marine ecological speciation in coastal regions that lack physical dispersal barriers.
Collapse
Affiliation(s)
- Peter R. Teske
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park 2006, South Africa
| | - Jonathan Sandoval-Castillo
- Molecular Ecology Lab, College of Science and Engineering, Flinders University, Adelaide 5001, Australia
| | - Tirupathi Rao Golla
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park 2006, South Africa
| | - Arsalan Emami-Khoyi
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park 2006, South Africa
| | - Mbaye Tine
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park 2006, South Africa
| | - Sophie von der Heyden
- Evolutionary Genomics Lab, Department of Botany and Zoology, Stellenbosch University, Matieland 7602, South Africa
| | - Luciano B. Beheregaray
- Molecular Ecology Lab, College of Science and Engineering, Flinders University, Adelaide 5001, Australia
| |
Collapse
|
10
|
Singh SP, Groeneveld JC, Hart‐Davis MG, Backeberg BC, Willows‐Munro S. Seascape genetics of the spiny lobster Panulirus homarus in the Western Indian Ocean: Understanding how oceanographic features shape the genetic structure of species with high larval dispersal potential. Ecol Evol 2018; 8:12221-12237. [PMID: 30598813 PMCID: PMC6303728 DOI: 10.1002/ece3.4684] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 09/13/2018] [Accepted: 09/14/2018] [Indexed: 01/03/2023] Open
Abstract
This study examines the fine-scale population genetic structure and phylogeography of the spiny lobster Panulirus homarus in the Western Indian Ocean. A seascape genetics approach was used to relate the observed genetic structure based on 21 microsatellite loci to ocean circulation patterns, and to determine the influence of latitude, sea surface temperature (SST), and ocean turbidity (KD490) on population-level processes. At a geospatial level, the genetic clusters recovered corresponded to three putative subspecies, P. h. rubellus from the SW Indian Ocean, P. h. megasculptus from the NW Indian Ocean, and P. h. homarus from the tropical region in-between. Virtual passive Lagrangian particles advected using satellite-derived ocean surface currents were used to simulate larval dispersal. In the SW Indian Ocean, the dispersion of particles tracked over a 4-month period provided insight into a steep genetic gradient observed at the Delagoa Bight, which separates P. h. rubellus and P. h. homarus. South of the contact zone, particles were advected southwestwards by prevailing boundary currents or were retained in nearshore eddies close to release locations. Some particles released in southeast Madagascar dispersed across the Mozambique Channel and reached the African shelf. Dispersal was characterized by high seasonal and inter-annual variability, and a large proportion of particles were dispersed far offshore and presumably lost. In the NW Indian Ocean, particles were retained within the Arabian Sea. Larval retention and self-recruitment in the Arabian Sea could explain the recent genetic divergence between P. h. megasculptus and P. h. homarus. Geographic distance and minimum SST were significantly associated with genetic differentiation in multivariate analysis, suggesting that larval tolerance to SST plays a role in shaping the population structure of P. homarus.
Collapse
Affiliation(s)
- Sohana P. Singh
- Oceanographic Research InstituteMarine ParadeSouth Africa
- School of Life SciencesUniversity of KwaZulu‐NatalPietermaritzburgSouth Africa
| | - Johan C. Groeneveld
- Oceanographic Research InstituteMarine ParadeSouth Africa
- School of Life SciencesUniversity of KwaZulu‐NatalPietermaritzburgSouth Africa
| | - Michael G. Hart‐Davis
- Institute for Coastal and Marine ResearchNelson Mandela UniversityPort ElizabethSouth Africa
- Department of Oceanography, Nansen‐Tutu Centre for Marine Environmental ResearchUniversity of Cape TownSouth Africa
- Egagasini NodeSouth African Environmental Observation NetworkCape TownSouth Africa
| | - Björn C. Backeberg
- Department of Oceanography, Nansen‐Tutu Centre for Marine Environmental ResearchUniversity of Cape TownSouth Africa
- Council for Scientific and Industrial Research, Natural Resources and the EnvironmentCoastal Systems Research GroupStellenboschSouth Africa
- Nansen Environmental and Remote Sensing CenterBergenNorway
| | - Sandi Willows‐Munro
- School of Life SciencesUniversity of KwaZulu‐NatalPietermaritzburgSouth Africa
| |
Collapse
|
11
|
Lastrucci NS, Nunes LT, Lindner A, Floeter SR. An updated phylogeny of the redlip blenny genus Ophioblennius. J Fish Biol 2018; 93:411-414. [PMID: 29961969 DOI: 10.1111/jfb.13732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 06/15/2018] [Indexed: 06/08/2023]
Abstract
An updated molecular phylogeny of the blenny genus Ophioblennius, with a focus on two geographically disjunct morphotypes observed in Brazil, is presented. The analyses showed that specimens from the north-eastern Brazilian coast are the endemic redlip blenny Ophioblennius trinitatis, but specimens from the southern Brazilian coast are conspecific to an undescribed east Atlantic Ocean (Gulf of Guinea) species, previously unknown in Brazil. Possible explanations for this geographical pattern include: natural larval dispersal and rafting across the Atlantic; an unknown ecological attribute that enabled this species to colonize southern Brazil; oil platforms as introduction vectors.
Collapse
Affiliation(s)
- Naomi S Lastrucci
- Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Lucas T Nunes
- Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Alberto Lindner
- Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| | - Sergio R Floeter
- Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis, Brazil
| |
Collapse
|
12
|
Goulding TC, Khalil M, Tan SH, Dayrat B. Integrative taxonomy of a new and highly-diverse genus of onchidiid slugs from the Coral Triangle (Gastropoda, Pulmonata, Onchidiidae). Zookeys 2018:1-111. [PMID: 29896045 PMCID: PMC5996013 DOI: 10.3897/zookeys.763.21252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 05/08/2018] [Indexed: 11/15/2022] Open
Abstract
A new genus of onchidiid slugs, Wallaconchis Goulding & Dayrat, gen. n., is described, including ten species. Five species were previously described but known only from the type material: Wallaconchisater (Lesson, 1830), W.graniferum (Semper, 1880), W.nangkauriense (Plate, 1893), W.buetschlii (Stantschinsky, 1907), and W.gracile (Stantschinsky, 1907), all of which were originally classified in Onchidium Buchannan, 1800. Many new records are provided for these five species, which greatly expand their known geographic distributions. Five species are new: Wallaconchisachleitneri Goulding, sp. n., W.comendadori Goulding & Dayrat, sp. n., W.melanesiensis Goulding & Dayrat, sp. n., W.sinanui Goulding & Dayrat, sp. n., and W.uncinus Goulding & Dayrat, sp. n. Nine of the ten Wallaconchis species are found in the Coral Triangle (eastern Indonesia and the Philippines). Sympatry is high, with up to six species found on the island of Bohol (Philippines) and eight species overlapping in northern Sulawesi (Indonesia). Wallaconchis is distinguished from other onchidiids by its bright dorsal colors (red, yellow, orange) but those are extremely variable and not useful for specific identification. Internally, the reproductive system can be used to identify all Wallaconchis species. The copulatory organs of Wallaconchis species are especially diverse compared to other onchidiid genera, and the possible role of reproductive incompatibility in species diversification is discussed. All specimens examined were freshly collected for the purpose of a worldwide revision of the Onchidiidae Rafinesque, 1815. The species are well delineated using DNA sequences and comparative anatomy. Mitochondrial DNA analysis yields thirteen molecular units separated by a large barcode gap, while nuclear DNA yields nine units. By integrating nuclear DNA and mitochondrial DNA with morphology, ten species are recognized. The natural history of each species (e.g., the microhabitat where they are found) is also documented. Nomenclature is addressed thoroughly (the types of all onchidiid species were examined, lectotypes were designated when needed, nomina dubia are discussed). Morphological characters, transitions to new microhabitats, and diversification processes are discussed in the context of a robust molecular phylogeny.
Collapse
Affiliation(s)
- Tricia C Goulding
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA.,Current address: Bernice Pauahi Bishop Museum, 1525 Bernice St, Honolulu, HI 96817
| | - Munawar Khalil
- Department of Marine Science, Universitas Malikussaleh. Reuleut Main Campus, Kecamatan Muara Batu, North Aceh, Aceh, 24355, Indonesia
| | - Shau Hwai Tan
- Marine Science Laboratory, School of Biological Sciences, and Centre for Marine and Coastal Studies, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Benoît Dayrat
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|
13
|
Abstract
Recent years have witnessed growing appreciation for the ways in which human-mediated species introductions have reshaped marine biogeography. Despite this we have yet to grapple fully with the scale and impact of anthropogenic dispersal in both creating and determining contemporary distributions of marine taxa. In particular, the past several decades of research on marine biological invasions have revealed that broad geographic distributions of coastal marine organisms-historically referred to simply as "cosmopolitanism"-may belie complex interplay of both natural and anthropogenic processes. Here we describe a framework for understanding contemporary cosmopolitanism, informed by a synthesis of the marine bioinvasion literature. Our framework defines several novel categories in an attempt to provide a unified terminology for discussing cosmopolitan distributions in the world's oceans. We reserve the term eucosmopolitan to refer to those species for which data exist to support a true, natural, and prehistorically global (or extremely broad) distribution. While in the past this has been the default assumption for species observed to exhibit contemporary cosmopolitan distributions, we argue that given recent advances in marine invasion science this assignment should require positive evidence. In contrast, neocosmopolitan describes those species that have demonstrably achieved extensive geographic ranges only through historical anthropogenic dispersal, often facilitated over centuries of human maritime traffic. We discuss the history and human geography underpinning these neocosmopolitan distributions, and illustrate the extent to which these factors may have altered natural biogeographic patterns. We define the category pseudocosmopolitan to encompass taxa for which a broad distribution is determined (typically after molecular investigation) to reflect multiple, sometimes regionally endemic, lineages with uncertain taxonomic status; such species may remain cosmopolitan only so long as taxonomic uncertainty persists, after which they may splinter into multiple geographically restricted species. We discuss the methods employed to identify such species and to resolve both their taxonomic status and their biogeographic histories. We argue that recognizing these different types of cosmopolitanism, and the important role that invasion science has played in understanding them, is critically important for the future study of both historical and modern marine biogeography, ecology, and biodiversity.
Collapse
Affiliation(s)
- John A. Darling
- United States Environmental Protection Agency, National Exposure Research Laboratory, Research Triangle Park, NC, United States
| | - James T. Carlton
- Maritime Studies Program, Williams College-Mystic Seaport, Mystic, CT, United States
- Department of Biology, Williams College, Williamstown, MA, United States
| |
Collapse
|
14
|
Hellberg ME. SYMPATRIC SEA SHELLS ALONG THE SEA'S SHORE: THE GEOGRAPHY OF SPECIATION IN THE MARINE GASTROPOD TEGULA. Evolution 2017; 52:1311-1324. [PMID: 28565375 DOI: 10.1111/j.1558-5646.1998.tb02013.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/1997] [Accepted: 06/02/1998] [Indexed: 11/29/2022]
Abstract
Uncertainty and controversy surround the geographical and ecological circumstances that create genetic differences between populations that eventually lead to reproductive isolation. Two aspects of marine organisms further complicate this situation: (1) many species possess planktonic larvae capable of great dispersal; and (2) obvious barriers to movement between populations are rare. Past studies of speciation in the sea have focussed on identifying the effects of past land barriers and on biogeographical breakpoints. However, assessing the role such undeniable barriers actually play in the initial divergence leading to reproductive isolation requires phylogenetic studies of recent radiations living in varying degrees of sympatry and allopatry to see which barriers (if any) tend to separate sister species. Here I infer phylogenetic relationship between 23 species of the marine snail Tegula using DNA sequences from two regions of the mitochondrial genome: cytochrome c oxidase I (COI) and the small ribosomal subunit (12S) These snails possess planktonic larvae with moderate dispersal capabilities and have speciated rapidly with over 40 extant species arising since the genus first appeared in the mid-Miocene (about 15 M.Y.B.P.). Trees constructed from the COI and 12S regions (which yielded 205 and 137 phylogenetically informative sites, respectively) were robust with respect to tree-building method, bootstrapping, and the relative weightings of transitions, transversions, and gaps Within clades where all extant species have been sampled, five of six identified sister species pairs broadly coexist on the same side of biogeographical boundaries. These data suggest strong geographical barriers to gene flow may not always be required for speciation in the sea; transient allopatry or even ecological barriers may suffice. A survey of the geographic distributions of marine radiations suggests that coastal distributions may favor the sympatry of sister taxa more than island distributions do.
Collapse
Affiliation(s)
- Michael E Hellberg
- Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, California, 92093-0202
| |
Collapse
|
15
|
López BA, Macaya EC, Tala F, Tellier F, Thiel M. The variable routes of rafting: stranding dynamics of floating bull kelp Durvillaea antarctica (Fucales, Phaeophyceae) on beaches in the SE Pacific. J Phycol 2017; 53:70-84. [PMID: 27734500 DOI: 10.1111/jpy.12479] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 09/05/2016] [Indexed: 06/06/2023]
Abstract
Dispersal on floating seaweeds depends on availability, viability, and trajectories of the rafts. In the southern hemisphere, the bull kelp Durvillaea antarctica is one of the most common floating seaweeds, but phylogeographic studies had shown low connectivity between populations from continental Chile, which could be due to limitations in local supply and dispersal of floating kelps. To test this hypothesis, the spatiotemporal dynamics of kelp strandings were examined in four biogeographic districts along the Chilean coast (28°-42°S). We determined the biomass and demography of stranded individuals on 33 beaches for three subsequent years (2013, 2014, 2015) to examine whether rafting is restricted to certain districts and seasons (winter or summer). Stranded kelps were found on all beaches. Most kelps had only one stipe (one individual), although we also frequently found coalesced holdfasts with mature males and females, which would facilitate successful rafting dispersal, gamete release, and reproduction upon arrival. High biomasses of stranded kelps occurred in the northern-central (30°S-33°S) and southernmost districts (37°S-42°S), and lower biomasses in the northernmost (28°S-30°S) and southern-central districts (33°S-37°S). The highest percentages and sizes of epibionts (Lepas spp.), indicative of prolonged floating periods, were found on stranded kelps in the northernmost and southernmost districts. Based on these results, we conclude that rafting dispersal can vary regionally, being more common in the northernmost and southernmost districts, depending on intrinsic (seaweed biology) and extrinsic factors (shore morphology and oceanography) that affect local supply of kelps and regional hydrodynamics.
Collapse
Affiliation(s)
- Boris A López
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
- Departamento de Acuicultura y Recursos Agroalimentarios, Universidad de Los Lagos, Avenida Fuchslocher 1305, Osorno, Chile
| | - Erasmo C Macaya
- Laboratorio de Estudios Algales (ALGALAB), Departamento de Oceanografía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
- Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
- Centro FONDAP de Investigaciones en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia, Chile
| | - Fadia Tala
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
- Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
| | - Florence Tellier
- Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile
- Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile
| | - Martin Thiel
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
- Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
- Centro de Estudios Avanzados en Zonas Áridas, CEAZA, Coquimbo, Chile
| |
Collapse
|
16
|
Kiel S. A biogeographic network reveals evolutionary links between deep-sea hydrothermal vent and methane seep faunas. Proc Biol Sci 2016; 283:20162337. [PMID: 27974524 PMCID: PMC5204157 DOI: 10.1098/rspb.2016.2337] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 11/08/2016] [Indexed: 11/12/2022] Open
Abstract
Deep-sea hydrothermal vents and methane seeps are inhabited by members of the same higher taxa but share few species, thus scientists have long sought habitats or regions of intermediate character that would facilitate connectivity among these habitats. Here, a network analysis of 79 vent, seep, and whale-fall communities with 121 genus-level taxa identified sedimented vents as a main intermediate link between the two types of ecosystems. Sedimented vents share hot, metal-rich fluids with mid-ocean ridge-type vents and soft sediment with seeps. Such sites are common along the active continental margins of the Pacific Ocean, facilitating connectivity among vent/seep faunas in this region. By contrast, sedimented vents are rare in the Atlantic Ocean, offering an explanation for the greater distinction between its vent and seep faunas compared with those of the Pacific Ocean. The distribution of subduction zones and associated back-arc basins, where sedimented vents are common, likely plays a major role in the evolutionary and biogeographic connectivity of vent and seep faunas. The hypothesis that decaying whale carcasses are dispersal stepping stones linking these environments is not supported.
Collapse
Affiliation(s)
- Steffen Kiel
- Department of Palaeobiology, Swedish Museum of Natural History, PO Box 50007, Stockholm 10405, Sweden
| |
Collapse
|
17
|
Eilertsen MH, Malaquias MAE. Speciation in the dark: diversification and biogeography of the deep-sea gastropod genus Scaphander in the Atlantic Ocean. J Biogeogr 2015; 42:843-855. [PMID: 27524853 PMCID: PMC4964956 DOI: 10.1111/jbi.12471] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
AIM The aim of this work was to improve understanding about the mode, geography and tempo of diversification in deep-sea organisms, using a time-calibrated molecular phylogeny of the heterobranch gastropod genus Scaphander. LOCATION Atlantic and Indo-West Pacific (IWP) oceans. METHODS Two mitochondrial gene markers (COI and 16S) and one nuclear ribosomal gene (28S) from six Atlantic species of Scaphander, and four IWP species were used to generate a multilocus phylogenetic hypothesis using uncorrelated relaxed-clock Bayesian methods implemented in beast and calibrated with the first occurrence of Scaphander in the fossil record (58.7-55.8 Ma). RESULTS Two main clades were supported: clade A, with sister relationships between species and subclades from the Atlantic and IWP; and clade B, with two western Atlantic sister species. Our estimates indicate that the two earliest divergences in clade A occurred between the middle Eocene and late Miocene and the most recent speciation occurred within the middle Miocene to Pleistocene. The divergence between the two western Atlantic species in clade B was estimated at late Oligocene-Pliocene. MAIN CONCLUSIONS The prevailing mode of speciation in Scaphander was allopatric, but one possible case of sympatric speciation was detected between two western Atlantic species. Sister relationships between IWP and Atlantic lineages suggest the occurrence both of vicariance events caused by the closure of the Tethyan Seaway and of dispersal between the two ocean basins, probably around South Africa during episodic disruptions of the deep-sea regional current system caused by glacial-interglacial cycles. Cladogenetic estimates do not support comparatively older diversification of deep-sea faunas, but corroborate the hypothesis of a pulse of diversification centred in the Oligocene and Miocene epochs. Amphi-Atlantic species were found to occur at deeper depths (bathyal-abyssal) and we hypothesize that trans-Atlantic connectivity is maintained by dispersal between neighbouring reproductive populations inhabiting the abyssal sea floor and by dispersal across the shelf and slope of Arctic and sub-Arctic regions.
Collapse
Affiliation(s)
- Mari H. Eilertsen
- Marine Biodiversity Research GroupDepartment of BiologyUniversity of Bergen5006BergenNorway
| | - Manuel António E. Malaquias
- Phylogenetic Systematics and Evolution Research GroupDepartment of Natural HistoryUniversity Museum of BergenUniversity of Bergen5020BergenNorway
| |
Collapse
|
18
|
Abstract
The biogeochemical role of phytoplanktonic organisms strongly varies from one plankton type to another, and their relative abundance and distribution have fundamental consequences at the global and climatological scales. In situ observations find dominant types often associated to specific physical and chemical water properties. However, the mechanisms and spatiotemporal scales by which marine ecosystems are organized are largely not known. Here we investigate the spatiotemporal organization of phytoplankton communities by combining multisatellite data, notably high-resolution ocean-color maps of dominant types and altimetry-derived Lagrangian diagnostics of the surface transport. We find that the phytoplanktonic landscape is organized in (sub-)mesoscale patches (10-100 km) of dominant types separated by physical fronts induced by horizontal stirring. These physical fronts delimit niches supported by water masses of similar history and whose lifetimes are comparable with the timescale of the bloom onset (few weeks). The resonance between biological activity and physical processes suggest that the spatiotemporal (sub-)mesoscales associated to stirring are determinant in the observation and modeling of marine ecosystems.
Collapse
Affiliation(s)
- Francesco d’Ovidio
- Institut des Systémes Complexes—Paris Île-de-France, 57-59 rue Lohmond, 75005 Paris, France
- Laboratoire d’Océanographie et du Climat: Expérimentation et Approches Numériques—Institut Pierre Simon Laplace, Université Pierre et Marie Curie, BC 100, 4 place Jussieu, 75005 Paris, France
| | - Silvia De Monte
- École Normale Supérieure, Unité Mixte de Recherche 7625, Écologie et Évolution, 46 rue d’Ulm, 75005 Paris, France
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche 7625, Écologie et Évolution, CC 237-7 quai Saint Bernard, 75005 Paris, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7625, Écologie et Évolution, 46 rue d'Ulm, 75005 Paris, France; and
| | - Séverine Alvain
- Laboratoire d’Océanologie et de Géosciences, Centre National de la Recherche Scientifique-Unité Mixte de Recherche 8187, 32 Avenue Foch, 62930 Wimereux, France
| | - Yves Dandonneau
- Laboratoire d’Océanographie et du Climat: Expérimentation et Approches Numériques—Institut Pierre Simon Laplace, Université Pierre et Marie Curie, BC 100, 4 place Jussieu, 75005 Paris, France
| | - Marina Lévy
- Laboratoire d’Océanographie et du Climat: Expérimentation et Approches Numériques—Institut Pierre Simon Laplace, Université Pierre et Marie Curie, BC 100, 4 place Jussieu, 75005 Paris, France
| |
Collapse
|
19
|
Abstract
The high biodiversity in tropical seas provides a long-standing challenge to allopatric speciation models. Physical barriers are few in the ocean and larval dispersal is often extensive, a combination that should reduce opportunities for speciation. Yet coral reefs are among the most species-rich habitats in the world, indicating evolutionary processes beyond conventional allopatry. In a survey of mtDNA sequences of five congeneric west Atlantic reef fishes (wrasses, genus Halichoeres) with similar dispersal potential, we observed phylogeographical patterns that contradict expectations of geographical isolation, and instead indicate a role for ecological speciation. In Halichoeres bivittatus and the species pair Halichoeres radiatus/brasiliensis, we observed strong partitions (3.4% and 2.3% divergence, respectively) between adjacent and ecologically distinct habitats, but high genetic connectivity between similar habitats separated by thousands of kilometres. This habitat partitioning is maintained even at a local scale where H. bivittatus lineages are segregated between cold- and warm-water habitats in both Bermuda and Florida. The concordance of evolutionary partitions with habitat types, rather than conventional biogeographical barriers, indicates parapatric ecological speciation, in which adaptation to alternative environmental conditions in adjacent locations overwhelms the homogenizing effect of dispersal. This mechanism can explain the long-standing enigma of high biodiversity in coral reef faunas.
Collapse
Affiliation(s)
- Luiz A Rocha
- Department of Fisheries and Aquatic Sciences, University of Florida, 7922, NW 71st Street, Gainesville, FL 32653, USA.
| | | | | | | |
Collapse
|