1
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Simon-Lledó E, Amon DJ, Bribiesca-Contreras G, Cuvelier D, Durden JM, Ramalho SP, Uhlenkott K, Arbizu PM, Benoist N, Copley J, Dahlgren TG, Glover AG, Fleming B, Horton T, Ju SJ, Mejía-Saenz A, McQuaid K, Pape E, Park C, Smith CR, Jones DOB. Carbonate compensation depth drives abyssal biogeography in the northeast Pacific. Nat Ecol Evol 2023; 7:1388-1397. [PMID: 37488225 PMCID: PMC10482686 DOI: 10.1038/s41559-023-02122-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/08/2023] [Indexed: 07/26/2023]
Abstract
Abyssal seafloor communities cover more than 60% of Earth's surface. Despite their great size, abyssal plains extend across modest environmental gradients compared to other marine ecosystems. However, little is known about the patterns and processes regulating biodiversity or potentially delimiting biogeographical boundaries at regional scales in the abyss. Improved macroecological understanding of remote abyssal environments is urgent as threats of widespread anthropogenic disturbance grow in the deep ocean. Here, we use a new, basin-scale dataset to show the existence of clear regional zonation in abyssal communities across the 5,000 km span of the Clarion-Clipperton Zone (northeast Pacific), an area targeted for deep-sea mining. We found two pronounced biogeographic provinces, deep and shallow-abyssal, separated by a transition zone between 4,300 and 4,800 m depth. Surprisingly, species richness was maintained across this boundary by phylum-level taxonomic replacements. These regional transitions are probably related to calcium carbonate saturation boundaries as taxa dependent on calcium carbonate structures, such as shelled molluscs, appear restricted to the shallower province. Our results suggest geochemical and climatic forcing on distributions of abyssal populations over large spatial scales and provide a potential paradigm for deep-sea macroecology, opening a new basis for regional-scale biodiversity research and conservation strategies in Earth's largest biome.
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Affiliation(s)
| | - Diva J Amon
- SpeSeas, D'Abadie, Trinidad and Tobago
- Marine Science Institute, University of California, Santa Barbara, CA, USA
| | | | - Daphne Cuvelier
- Institute of Marine Sciences-Okeanos, University of the Azores, Horta, Portugal
| | | | - Sofia P Ramalho
- Centre for Environmental and Marine Studies & Department of Biology, University of Aveiro, Aveiro, Portugal
| | - Katja Uhlenkott
- German Centre for Marine Biodiversity Research, Senckenberg am Meer, Wilhelmshaven, Germany
- Institute for Biology and Environmental Sciences, Carl von Ossietzky University, Oldenburg, Germany
| | - Pedro Martinez Arbizu
- German Centre for Marine Biodiversity Research, Senckenberg am Meer, Wilhelmshaven, Germany
| | | | - Jonathan Copley
- Ocean & Earth Science, University of Southampton, Southampton, UK
| | - Thomas G Dahlgren
- NORCE Climate and Environment, Bergen, Norway
- Department of Marine Sciences, University of Gothenburg, Göteborg, Sweden
| | | | - Bethany Fleming
- National Oceanography Centre, Southampton, UK
- Ocean & Earth Science, University of Southampton, Southampton, UK
| | | | - Se-Jong Ju
- Korea Institute of Ocean Science and Technology, Busan, South Korea
- Ocean Science Major, University of Science and Technology, Daejeon, South Korea
| | | | | | - Ellen Pape
- Marine Biology Research Group, Ghent University, Ghent, Belgium
| | - Chailinn Park
- Korea Institute of Ocean Science and Technology, Busan, South Korea
- Ocean Science Major, University of Science and Technology, Daejeon, South Korea
| | - Craig R Smith
- Department of Oceanography, University of Hawai'i at Manoa, Honolulu, HI, USA
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2
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Rabone M, Wiethase JH, Simon-Lledó E, Emery AM, Jones DOB, Dahlgren TG, Bribiesca-Contreras G, Wiklund H, Horton T, Glover AG. How many metazoan species live in the world's largest mineral exploration region? Curr Biol 2023; 33:2383-2396.e5. [PMID: 37236182 DOI: 10.1016/j.cub.2023.04.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/22/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023]
Abstract
The global surge in demand for metals such as cobalt and nickel has created unprecedented interest in deep-sea habitats with mineral resources. The largest area of activity is a 6 million km2 region known as the Clarion-Clipperton Zone (CCZ) in the central and eastern Pacific, regulated by the International Seabed Authority (ISA). Baseline biodiversity knowledge of the region is crucial to effective management of environmental impact from potential deep-sea mining activities, but until recently this has been almost completely lacking. The rapid growth in taxonomic outputs and data availability for the region over the last decade has allowed us to conduct the first comprehensive synthesis of CCZ benthic metazoan biodiversity for all faunal size classes. Here we present the CCZ Checklist, a biodiversity inventory of benthic metazoa vital to future assessments of environmental impacts. An estimated 92% of species identified from the CCZ are new to science (436 named species from a total of 5,578 recorded). This is likely to be an overestimate owing to synonyms in the data but is supported by analysis of recent taxonomic studies suggesting that 88% of species sampled in the region are undescribed. Species richness estimators place total CCZ metazoan benthic diversity at 6,233 (+/-82 SE) species for Chao1, and 7,620 (+/-132 SE) species for Chao2, most likely representing lower bounds of diversity in the region. Although uncertainty in estimates is high, regional syntheses become increasingly possible as comparable datasets accumulate. These will be vital to understanding ecological processes and risks of biodiversity loss.
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Affiliation(s)
- Muriel Rabone
- Deep-Sea Systematics and Ecology Group, Life Sciences Department, Natural History Museum, Cromwell Rd, SW7 5BD London, UK.
| | - Joris H Wiethase
- Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Erik Simon-Lledó
- National Oceanography Centre, European Way, SO14 3ZH Southampton, UK
| | - Aidan M Emery
- Deep-Sea Systematics and Ecology Group, Life Sciences Department, Natural History Museum, Cromwell Rd, SW7 5BD London, UK
| | - Daniel O B Jones
- National Oceanography Centre, European Way, SO14 3ZH Southampton, UK
| | - Thomas G Dahlgren
- Department of Marine Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden; NORCE, Norwegian Research Centre, 112, 5008 Bergen, Norway
| | - Guadalupe Bribiesca-Contreras
- Deep-Sea Systematics and Ecology Group, Life Sciences Department, Natural History Museum, Cromwell Rd, SW7 5BD London, UK
| | - Helena Wiklund
- Deep-Sea Systematics and Ecology Group, Life Sciences Department, Natural History Museum, Cromwell Rd, SW7 5BD London, UK; Department of Marine Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Tammy Horton
- National Oceanography Centre, European Way, SO14 3ZH Southampton, UK
| | - Adrian G Glover
- Deep-Sea Systematics and Ecology Group, Life Sciences Department, Natural History Museum, Cromwell Rd, SW7 5BD London, UK
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3
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Stewart ECD, Bribiesca‐Contreras G, Taboada S, Wiklund H, Ravara A, Pape E, De Smet B, Neal L, Cunha MR, Jones DOB, Smith CR, Glover AG, Dahlgren TG. Biodiversity, biogeography, and connectivity of polychaetes in the world's largest marine minerals exploration frontier. DIVERS DISTRIB 2023. [DOI: 10.1111/ddi.13690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
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4
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Turner RL, O'Neill BO. A Sister-Group Comparison of Branching and Pedicellariae in Brittlestars (Echinodermata: Ophiuroidea). Integr Org Biol 2023; 5:obad013. [PMID: 37151601 PMCID: PMC10155225 DOI: 10.1093/iob/obad013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 03/27/2023] [Accepted: 04/12/2023] [Indexed: 05/09/2023] Open
Abstract
Branching of arms and presence of pedicellariae are characters among ophiuroids found only in the order Euryalida (snakestars and basketstars). Family Asteronychidae has neither character; family Euryalidae has 2 small clades with branched arms; and family Gorgonocephalidae has all species with pedicellariae and 3 or 4 clades with branched arms. Despite the rare occurrence of these characters in the Ophiuroidea, they might be key adaptations within the Euryalida that have led to relatively high diversification. Sister-group comparison of the distribution of these 2 characters among taxa indicates that neither character alone explains diversity patterns within the order. In particular, branching restricted to the tips of arms seems not strongly adaptive, probably for the lack of integration of basal forks with the disc. On the other hand, 2 clades of gorgonocephalids with basal branching exceed their snakestar sister groups in numbers of species, indicating an advantage of branching within the family. Unfortunately, the analysis cannot benefit from statistics, for at least 5 independent comparisons are required for a one-tailed sign test. Because branching and pedicellariae are probably not independent variables, future sister-group comparisons should be done only within the Gorgonocephalidae once clade structure is better clarified with increased taxon sampling (10 currently missing genera) and resolution of intra-generic inconsistencies in the most recent cladograms available. Branching might confer upon gorgonocephalid basketstars a more efficient use of pedicellariae for upstream capture of zooplankton over their snakestar relatives as well as over the Euryalidae, which retain ancestral downstream capture by mucus-laden podia.
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Affiliation(s)
| | - B O O'Neill
- Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, Melbourne, FL 32901, USA
- 11125 West 45th Ave., Wheat Ridge, CO 80033, USA
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5
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Bribiesca-Contreras G, Dahlgren TG, Amon DJ, Cairns S, Drennan R, Durden JM, Eléaume MP, Hosie AM, Kremenetskaia A, McQuaid K, O’Hara TD, Rabone M, Simon-Lledó E, Smith CR, Watling L, Wiklund H, Glover AG. Benthic megafauna of the western Clarion-Clipperton Zone, Pacific Ocean. Zookeys 2022; 1113:1-110. [PMID: 36762231 PMCID: PMC9848802 DOI: 10.3897/zookeys.1113.82172] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 05/05/2022] [Indexed: 11/12/2022] Open
Abstract
There is a growing interest in the exploitation of deep-sea mineral deposits, particularly on the abyssal seafloor of the central Pacific Clarion-Clipperton Zone (CCZ), which is rich in polymetallic nodules. In order to effectively manage potential exploitation activities, a thorough understanding of the biodiversity, community structure, species ranges, connectivity, and ecosystem functions across a range of scales is needed. The benthic megafauna plays an important role in the functioning of deep-sea ecosystems and represents an important component of the biodiversity. While megafaunal surveys using video and still images have provided insight into CCZ biodiversity, the collection of faunal samples is needed to confirm species identifications to accurately estimate species richness and species ranges, but faunal collections are very rarely carried out. Using a Remotely Operated Vehicle, 55 specimens of benthic megafauna were collected from seamounts and abyssal plains in three Areas of Particular Environmental Interest (APEI 1, APEI 4, and APEI 7) at 3100-5100 m depth in the western CCZ. Using both morphological and molecular evidence, 48 different morphotypes belonging to five phyla were found, only nine referrable to known species, and 39 species potentially new to science. This work highlights the need for detailed taxonomic studies incorporating genetic data, not only within the CCZ, but in other bathyal, abyssal, and hadal regions, as representative genetic reference libraries that could facilitate the generation of species inventories.
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Affiliation(s)
- Guadalupe Bribiesca-Contreras
- Life Sciences Department, Natural History Museum, London, UK Life Sciences Department, Natural History MuseumLondonUnited Kingdom
| | - Thomas G. Dahlgren
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SwedenUniversity of GothenburgGothenburgSweden,Norwegian Research Centre, NORCE, Bergen, NorwayNorwegian Research Centre, NORCEBergenNorway
| | - Diva J. Amon
- SpeSeas, D’Abadie, Trinidad and TobagoSpeSeasD’AbadieTrinidad and Tobago
| | - Stephen Cairns
- Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, D.C., USANational Museum of Natural History, Smithsonian InstitutionWashingtonUnited States of America
| | - Regan Drennan
- National Oceanography Centre, Southampton, UKLife Sciences Department, Natural History MuseumLondonUnited Kingdom
| | - Jennifer M. Durden
- UMR ISYEB, Départment Origines et Évolution, Muséum national d’Histoire Naturelle, Paris, FranceNational Oceanography CentreSouthamptonUnited Kingdom
| | - Marc P. Eléaume
- Collections & Research, Western Australia Museum, Perth, AustraliaDépartment Origines et Évolution, Muséum national d’Histoire NaturelleParisFrance
| | - Andrew M. Hosie
- Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, RussiaCollections & Research, Western Australia MuseumPerthAustralia
| | - Antonina Kremenetskaia
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, UKShirshov Institute of Oceanology, Russian Academy of SciencesMoscowRussia
| | - Kirsty McQuaid
- Museums Victoria, Melbourne, AustraliaUniversity of PlymouthPlymouthUnited Kingdom
| | - Timothy D. O’Hara
- Department of Oceanography, University of Hawai’i at Mānoa, Honolulu, USAMuseums VictoriaMelbourneAustralia
| | - Muriel Rabone
- National Oceanography Centre, Southampton, UKLife Sciences Department, Natural History MuseumLondonUnited Kingdom
| | - Erik Simon-Lledó
- UMR ISYEB, Départment Origines et Évolution, Muséum national d’Histoire Naturelle, Paris, FranceNational Oceanography CentreSouthamptonUnited Kingdom
| | - Craig R. Smith
- School of Life Sciences, University of Hawai’i at Mānoa, Honolulu, USAUniversity of Hawai’i at MānoaHonoluluUnited States of America
| | - Les Watling
- School of Life Sciences, University of Hawai’i at Mānoa, Honolulu, USAUniversity of Hawai’i at MānoaHonoluluUnited States of America
| | - Helena Wiklund
- Department of Marine Sciences, University of Gothenburg, Gothenburg, SwedenUniversity of GothenburgGothenburgSweden
| | - Adrian G. Glover
- National Oceanography Centre, Southampton, UKLife Sciences Department, Natural History MuseumLondonUnited Kingdom
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6
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Goharimanesh M, Ghassemzadeh F, De Kegel B, Van Hoorebeke L, Stöhr S, Mirshamsi O, Adriaens D. The evolutionary relationship between arm vertebrae shape and ecological lifestyle in brittle stars (Echinodermata: Ophiuroidea). J Anat 2022; 240:1034-1047. [PMID: 34929059 PMCID: PMC9119616 DOI: 10.1111/joa.13617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 12/13/2021] [Accepted: 12/13/2021] [Indexed: 01/03/2023] Open
Abstract
Ophiuroidea are one of the most diverse classes among extant echinoderms, characterized by their flexible arms composed of a series of ossicles called vertebrae, articulating with each other proximally and distally. Their arms show a wide range of motion, important for feeding and locomotion, associated with their epizoic and non-epizoic lifestyles. It remains to be explored to what degree the phenotypic variation in these ossicles also reflects adaptations to these lifestyles, rather than only their phylogenetic affinity. In this study, we analyzed the 3D shape variation of six arm vertebrae from the middle and distal parts of an arm in 12 species, belonging to the intertidal, subtidal and bathyal zones and showing epizoic and non-epizoic behaviors. A PERMANOVA indicated a significant difference in ossicle morphology between species and between lifestyles. A principal component analysis showed that the morphology of epizoic ophiuroids is distinct from non-epizoic ones; which may reflect variation in arm function related to these different lifestyles. The Phylogenetic MANOVA and phylogenetic signal analysis showed that shape variation in the vertebral articulation seems to reflect ecological and functional adaptations, whereas phylogeny controls more the lateral morphology of the vertebrae. This suggests a convergent evolution through ecological adaptation to some degree, indicating that some of these characters may have limited taxonomic value.
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Affiliation(s)
- Mona Goharimanesh
- Department of BiologyFerdowsi University of MashhadMashhadIran
- Research Group Evolutionary Morphology of VertebratesGhent UniversityGentBelgium
| | | | - Barbara De Kegel
- Research Group Evolutionary Morphology of VertebratesGhent UniversityGentBelgium
| | - Luc Van Hoorebeke
- UGCT ‐ Department of Physics and AstronomyGhent UniversityGentBelgium
| | - Sabine Stöhr
- Department of ZoologySwedish Museum of Natural HistoryStockholmSweden
| | - Omid Mirshamsi
- Department of BiologyFerdowsi University of MashhadMashhadIran
| | - Dominique Adriaens
- Research Group Evolutionary Morphology of VertebratesGhent UniversityGentBelgium
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7
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Nethupul H, Stöhr S, Zhang H. Review of Ophioplinthaca Verrill, 1899 (Echinodermata, Ophiuroidea, Ophiacanthidae), description of new species in Ophioplinthaca and Ophiophthalmus, and new records from the Northwest Pacific and the South China Sea. Zookeys 2022; 1099:155-202. [PMID: 36761443 PMCID: PMC9848918 DOI: 10.3897/zookeys.1099.76479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 02/18/2022] [Indexed: 11/12/2022] Open
Abstract
The ophiuroid genus Ophioplinthaca is well characterized by the deep incisions in the disc. Prior to this study, it contained 32 accepted species, but species limits and geographic distributions were not well understood. The manned submersible vehicle 'Shenhaiyongshi' was used to collect ophiuroid specimens from the deep-sea seamounts and cold seeps in the South China Sea and Northwest Pacific at 602-3600 m depth, during 2018 to 2020. The genus Ophioplinthaca was reviewed using both morphological data and a phylogenetic analysis, based on COI sequences. The taxonomic status of the genus Ophiophthalmus Matsumoto, 1917, a junior homonym of Ophiophthalmus Fitzinger, 1843 (a reptile) was clarified by proving prevailing usage of the ophiuroid name. A total of eight species were identified, including two new species, described asOphioplinthacabrachispina sp. nov. and Ophiophthalmusserratus sp. nov., and two new records. The new species are characterized by unique features of the arm skeletons. Tabular keys to all Ophioplinthaca and Ophiophthalmus species are provided. Interspecific and intraspecific genetic distance of Ophioplinthaca species ranged from 2.32% to 19.72%, and from 0.26% to 0.90%, respectively. The data suggest that species of the genus Ophioplinthaca are more widely spread around the Northwest Pacific region deep-sea seamounts than previously known.
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Affiliation(s)
- Hasitha Nethupul
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, CAS, 57200 Sanya, ChinaInstitute of Deep-sea Science and Engineering, Chinese Academy of SciencesSanyaChina,University of Chinese Academy of Sciences, Beijing 100039, ChinaUniversity of Chinese Academy of SciencesBeijingChina
| | - Sabine Stöhr
- Swedish Museum of Natural History, Dept of Zoology, Box 50007, 10405 Stockholm, SwedenSwedish Museum of Natural History, Dept of ZoologyStockholmSweden
| | - Haibin Zhang
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, CAS, 57200 Sanya, ChinaInstitute of Deep-sea Science and Engineering, Chinese Academy of SciencesSanyaChina
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8
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Nethupul H, Stöhr S, Zhang H. Order Euryalida (Echinodermata, Ophiuroidea), new species and new records from the South China Sea and the Northwest Pacific seamounts. Zookeys 2022; 1090:161-216. [PMID: 35586844 PMCID: PMC9005471 DOI: 10.3897/zookeys.1090.76292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 02/02/2022] [Indexed: 11/21/2022] Open
Abstract
Ophiuroids were collected by the manned submersible ‘Shenhaiyongshi’ from the deep-sea seamounts in the South China Sea and Northwest Pacific regions at 602–1920 m depth, during 2018 to 2020. A total of nine species was identified, including two new species and seven new records from the South China Sea and one new record from the Northwest Pacific region. Two new species are described as Asteroschemashenhaiyongshiisp. nov. and Asteroschemadomogranulatumsp. nov. The seven new records included five species from the genus Asteroschema, and one species each from the genera Asterostegus and Astrodendrum. Comprehensive descriptions of morphological features are provided, including characteristics of the arm skeleton, as well as a phylogenetic analysis based on 16S and COI sequences. Intraspecific genetic distance ranges of Euryalida species from the present study were 0.34% to 1.38%, which was relatively low compared to other orders in the class Ophiuroidea. The present study suggests a high probability that species of the order Euryalida are more widely spread around the Indo-Pacific region than previously expected.
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9
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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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10
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Potential impacts of polymetallic nodule removal on deep-sea meiofauna. Sci Rep 2021; 11:19996. [PMID: 34620971 PMCID: PMC8497503 DOI: 10.1038/s41598-021-99441-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 09/17/2021] [Indexed: 11/17/2022] Open
Abstract
Deep seabed mining is potentially imminent in the Clarion Clipperton Fracture Zone (CCFZ; northeast Pacific). Seabed collectors will remove polymetallic nodules and the surrounding surface sediments, both inhabited by meiofauna, along their path. To determine potential impacts of polymetallic nodule removal, we investigated the importance of nodule presence for the abundance, composition and diversity of sediment meiofauna, and evaluated the existence and composition of nodule crevice meiofauna in the Global Sea Mineral Resources (GSR) exploration contract area. Nodule-free and nodule-rich sediments displayed high biodiversity with many singletons and doubletons, potentially representing rare taxa. Nodule presence negatively influenced sediment meiofaunal abundances but did not markedly affect taxonomic composition or diversity. This is the first report on CCFZ nodule crevice meiofauna, whose abundance related positively to nodule dimensions. Though dominated by the same taxa, nodules and sediments differed regarding the taxonomic and trophic composition of the meio- and nematofauna. Nevertheless, there were no taxa endemic to the nodule crevices and nodule crevice meiofauna added only little to total small-scale (~ cm) meiofaunal abundance and diversity. We formulated environmental management recommendations at the contract area and regional (CCFZ) scale related to sampling effort, set-aside preservation and monitoring areas, and potential rehabilitation measures.
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11
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Okanishi M, Kohtsuka H. Description of a New Brooding Species of Ophiodelos (Echinodermata: Ophiuroidea) from Japan. Zoolog Sci 2021; 38:352-358. [PMID: 34342956 DOI: 10.2108/zs200101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 02/20/2021] [Indexed: 11/17/2022]
Abstract
A new species of brittle star, Ophiodelos okayoshitakai, is described from two specimens collected in Sagami Bay, central-eastern Japan. Photographic examination of the holotype specimen of the sole other congener, Ophiodelos insignis Koehler, 1930, indicates that Ophiodelos okayoshitakai sp. nov. is distinguished from O. insignis by i) the disc stumps covering on the dorsal side of the disc, ii) the dorsal and ventral arm plates being separated from each other on the proximal arm regions, iii) the dorsal arm plate being smooth, iv) the arm spines at proximal portion of the arm being six in number and smooth in shape, and v) the number and shape of the tentacle scales at proximal portion of the arm being up to two and spine-shaped adradially and oval abradially. Detailed morphological observations of this new species suggest the inclusion of Ophiodelos, whose familial affiliation remains unclear, in the suborder Ophiacanthina. More than 10 juveniles of various sizes were found in the disc of Ophiodelos okayoshitakai sp. nov., indicating a brooding reproduction. This is the first report of the genus Ophiodelos from Japanese waters. We also provided a nucleotide sequence for part of the cytochrome c oxidase subunit I (COI) gene in O. okayoshitakai sp. nov. for future studies of DNA barcoding and phylogeny.
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Affiliation(s)
- Masanori Okanishi
- Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Misaki, Miura 238-0225, Japan,
| | - Hisanori Kohtsuka
- Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Misaki, Miura 238-0225, Japan
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12
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O'Hara TD, Thuy B, Hugall AF. Relict from the Jurassic: new family of brittle-stars from a New Caledonian seamount. Proc Biol Sci 2021; 288:20210684. [PMID: 34130505 DOI: 10.1098/rspb.2021.0684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The deep-seafloor in the tropical Indo-Pacific harbours a rich and diverse benthic fauna with numerous palaeoendemics. Here, we describe a new species, genus and family of brittle-star (Ophiuroidea) from a single eight-armed specimen collected from a depth between 360 and 560 m on Banc Durand, a seamount east of New Caledonia. Leveraging a robust, fossil-calibrated (265 kbp DNA) phylogeny for the Ophiuroidea, we estimate the new lineage diverged from other ophiacanthid families in the Late Triassic or Jurassic (median = 187-178 Myr, 95% CI = 215-143 Myr), a period of elevated diversification for this group. We further report very similar microfossil remains from Early Jurassic (180 Myr) sediments of Normandy, France. The discovery of a new ancient lineage in the relatively well-known Ophiuroidea indicates the importance of ongoing taxonomic research in the deep-sea, an environment increasingly threatened by human activities.
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Affiliation(s)
- Timothy D O'Hara
- Department of Sciences, Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia
| | - Ben Thuy
- Department of Palaeontology, Natural History Museum of Luxembourg, 24 Rue Münster, 2160 Luxembourg, Luxembourg
| | - Andrew F Hugall
- Department of Sciences, Museums Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia
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Polymetallic nodules are essential for food-web integrity of a prospective deep-seabed mining area in Pacific abyssal plains. Sci Rep 2021; 11:12238. [PMID: 34112864 PMCID: PMC8192577 DOI: 10.1038/s41598-021-91703-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/31/2021] [Indexed: 02/05/2023] Open
Abstract
Polymetallic nodule fields provide hard substrate for sessile organisms on the abyssal seafloor between 3000 and 6000 m water depth. Deep-seabed mining targets these mineral-rich nodules and will likely modify the consumer-resource (trophic) and substrate-providing (non-trophic) interactions within the abyssal food web. However, the importance of nodules and their associated sessile fauna in supporting food-web integrity remains unclear. Here, we use seafloor imagery and published literature to develop highly-resolved trophic and non-trophic interaction webs for the Clarion-Clipperton Fracture Zone (CCZ, central Pacific Ocean) and the Peru Basin (PB, South-East Pacific Ocean) and to assess how nodule removal may modify these networks. The CCZ interaction web included 1028 compartments connected with 59,793 links and the PB interaction web consisted of 342 compartments and 8044 links. We show that knock-down effects of nodule removal resulted in a 17.9% (CCZ) to 20.8% (PB) loss of all taxa and 22.8% (PB) to 30.6% (CCZ) loss of network links. Subsequent analysis identified stalked glass sponges living attached to the nodules as key structural species that supported a high diversity of associated fauna. We conclude that polymetallic nodules are critical for food-web integrity and that their absence will likely result in reduced local benthic biodiversity.
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Weber AAT, Hugall AF, O’Hara TD. Convergent Evolution and Structural Adaptation to the Deep Ocean in the Protein-Folding Chaperonin CCTα. Genome Biol Evol 2020; 12:1929-1942. [PMID: 32780796 PMCID: PMC7643608 DOI: 10.1093/gbe/evaa167] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/05/2020] [Indexed: 12/14/2022] Open
Abstract
The deep ocean is the largest biome on Earth and yet it is among the least studied environments of our planet. Life at great depths requires several specific adaptations; however, their molecular mechanisms remain understudied. We examined patterns of positive selection in 416 genes from four brittle star (Ophiuroidea) families displaying replicated events of deep-sea colonization (288 individuals from 216 species). We found consistent signatures of molecular convergence in functions related to protein biogenesis, including protein folding and translation. Five genes were recurrently positively selected, including chaperonin-containing TCP-1 subunit α (CCTα), which is essential for protein folding. Molecular convergence was detected at the functional and gene levels but not at the amino-acid level. Pressure-adapted proteins are expected to display higher stability to counteract the effects of denaturation. We thus examined in silico local protein stability of CCTα across the ophiuroid tree of life (967 individuals from 725 species) in a phylogenetically corrected context and found that deep-sea-adapted proteins display higher stability within and next to the substrate-binding region, which was confirmed by in silico global protein stability analyses. This suggests that CCTα displays not only structural but also functional adaptations to deep-water conditions. The CCT complex is involved in the folding of ∼10% of newly synthesized proteins and has previously been categorized as a "cold-shock" protein in numerous eukaryotes. We thus propose that adaptation mechanisms to cold and deep-sea environments may be linked and highlight that efficient protein biogenesis, including protein folding and translation, is a key metabolic deep-sea adaptation.
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Affiliation(s)
- Alexandra A -T Weber
- Sciences, Museums Victoria, Melbourne, Victoria, Australia
- Centre de Bretagne, REM/EEP, Ifremer, Laboratoire Environnement Profond, Plouzané, France
- Zoological Institute, University of Basel, Switzerland
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Okanishi M, Kohtsuka H, Fujita T. A taxonomic review of the genus Astrocladus (Echinodermata, Ophiuroidea, Euryalida, Gorgonocephalidae) from Japanese coastal waters. PeerJ 2020; 8:e9836. [PMID: 33083106 PMCID: PMC7547617 DOI: 10.7717/peerj.9836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/07/2020] [Indexed: 11/20/2022] Open
Abstract
Japanese species of the genus Astrocladus (Echinodermata, Ophiuroidea, Euryalida, Gorgonocephalidae) are reviewed. Astrocladus coniferus recently has two junior synonyms, A. dofleini Döderlein and A. pardalis Döderlein, however, status of these species has long been questioned. These species concepts have not been reviewed in recent years and no molecular phylogenetic analyses have been performed. Observations of the lectotype of A. coniferus, as well as the lectotype and four paralectotypes of A. dofleini and the holotype of A. pardalis have revealed that A. coniferus and A. pardalis are conspecific and morphologically distinguishable from A. dofleini. Astrocladus coniferus and A. dofleini are supported as distinct species by our molecular data. Additionally, we re-describe A. exiguus and A. annulatus, based on recently collected specimens and the holotype. We conclude that four species, A. annulatus, A. coniferus, A. dofleini, and A. exiguus are present in Japanese waters.
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Affiliation(s)
- Masanori Okanishi
- Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Miura, Kanagawa, Japan
| | - Hisanori Kohtsuka
- Misaki Marine Biological Station, Graduate School of Science, The University of Tokyo, Miura, Kanagawa, Japan
| | - Toshihiko Fujita
- Department of Zoology, National Museum of Nature and Science, Tsukuba, Tsukuba, Ibaraki, Japan
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Riehl T, De Smet B. Macrostylis metallicola spec. nov.-an isopod with geographically clustered genetic variability from a polymetallic-nodule area in the Clarion-Clipperton Fracture Zone. PeerJ 2020; 8:e8621. [PMID: 32149025 PMCID: PMC7049464 DOI: 10.7717/peerj.8621] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 01/22/2020] [Indexed: 11/20/2022] Open
Abstract
Background The Clarion-Clipperton Fracture Zone (CCFZ) in the Northeast Central Pacific Ocean is a region of heightened scientific and public interest because of its wealth in manganese nodules. Due to a poor ecological understanding at the abyssal seafloor and limited knowledge of the organisms inhabiting this area, huge efforts in alpha taxonomy are required. To predict and manage potential hazards associated with future mining, taxonomy is an essential first step to grasp fundamental ecosystem traits, such as biogeographic patterns, connectivity, and the potential for post-impact recolonization. Amongst samples from the Global Sea Mineral Resources NV exploration area (EA) in the CCFZ an undescribed species of the isopod crustacean family Macrostylidae was discovered. Previously, it has been reported from two other nearby regions, the Institut Français de Recherche pour l’Exploitation de la Mer and BGR EAs. There it was one of the more widely distributed and abundant species of the benthic macrofauna and exhibited geographically structured populations. It nevertheless remained taxonomically undescribed so far. Methods The new species is described by means of integrative taxonomy. Morphologically, macro photography, confocal microscopy, scanning electron microscopy and light microscopy were used to describe the species and to get first insights on its phylogenetic origin. Additionally, mitochondrial DNA markers were used to test the morphological allocation of the two dimorphic sexes and juvenile stages, to analyze geographic patterns of genetic differentiation, and to study intra-and inter-species relationships, also in light of previously published population genetics on this species. Results The new species, Macrostylis metallicola spec. nov., is a typical representative of Macrostylidae as recognizable from the fossosoma, prognathous cephalothorax, and styliform uropods. It can be morphologically distinguished from congeners by a combination of character states which include the autapomorphic shape of the first pleopod of the copulatory male. A sexual dimorphism, as expressed by a peculiar sequence of article length-width ratios of the male antennula, indicates a relationship with M. marionaeKniesz, Brandt & Riehl (2018) and M. longipesHansen (1916) amongst other species sharing this dimorphism. Mitochondrial genetic markers point in a similar direction. M. metallicola appears to be amongst the more common and widely distributed components of the benthic macrofauna in this region which may suggest a resilience of this species to future mining activities because of its apparent potential for recolonization of impacted sites from adjacent areas of particular environmental interest. The genetic data, however, show geographic clustering of its genetic variability, pointing towards a limited potential for dispersal. Local extinction of populations could potentially not be compensated quickly and would mean a loss of genetic diversity of this species.
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Affiliation(s)
- Torben Riehl
- Department of Marine Zoology, Section Crustacea, Senckenberg Research Institute and Natural History Museum, Frankfurt am Main, Germany.,Institute for Ecology, Evolution and Diversity, Johann Wolfgang Goethe Universität Frankfurt am Main, Frankfurt am Main, Germany.,Centre for Natural History, Zoological Museum, Universität Hamburg, Hamburg, Germany
| | - Bart De Smet
- Department of Biology, Marine Biology Research Group, Ghent University, Ghent, Belgium
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O'Hara TD, Williams A, Althaus F, Ross AS, Bax NJ. Regional‐scale patterns of deep seafloor biodiversity for conservation assessment. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
| | | | | | | | - Nicholas J. Bax
- CSIRO Oceans and Atmosphere Hobart TAS Australia
- Institute for Marine and Antarctic Science University of Tasmania Hobart TAS Australia
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