A massive and potentially ancient antipatharian colony at a seamount in the Northwest Pacific

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Here, we report on an extraordinarily large antipatharian colony observed on the Ritto Seamount in the Northwest Pacific. Based on colony form and DNA barcoding results, we identified the colony as Leiopathes cf. glaberrima . From in situ observations, we estimate the size of the colony as approximately 308 cm in height, 441 cm in width, with a central stem of 27.9 cm in diameter. If growth rates of Leiopathes species in this region of the Pacific Ocean are similar to those previously reported from Hawai’i, this colony may potentially be approximately several thousand years old, placing it among the longest-lived marine organisms reported. Seamounts in this region and such large antipatharians and other anthozoan colonies should be targeted for more biodiversity investigation and future conservation. Antipatharia Anthozoa Cnidaria Nishi-Shichito Ridge Ritto Seamount Figures Figure 1 Figure 2 Figure 3 Introduction Seamounts are important centers of marine biodiversity (Morato et al. 2010 ) and often harbor rich benthic communities (Rowden et al. 2003 ). Among benthic organisms, many reports have documented large and rich communities of anthozoans at seamounts around the world (Sinniger et al. 2013 ; Bo et al. 2021 ). As ecosystem engineers, anthozoans form the intricate foundation for diverse benthic communities, and as such have often been focused on in much research while discussing the need for their conservation (Bo et al. 2021 ). Indeed, the conservation of these “marine animal forests” (MAFs) are of urgent importance (Rossi et al. 2022 ). During a recent deep-sea research cruise aiming at characterizing the seamounts of the Nishi-Shichito and of the central and western Mariana ridges, we observed and recorded the fauna of Shotoku, Ritto, and Nikko seamounts. Among our observations, we recorded and investigated an extraordinarily large antipatharian colony, and here report on this unique observation. Materials and Methods Leg 2 of the Japan Agency for Marine Science and Technology (JAMSTEC) research cruise KM20-10C aboard the R/V Kaimei investigated the seamounts of the Nishi-Shichito and central and western Mariana ridges from December 2 to December 12, 2020 via observations and specimen collection utilizing the remotely operated vehicle KM-ROV . During dive KM-ROV #130 on December 5, 2020 at Ritto Seamount, we observed an extraordinarily large colony of antipatharian (Fig. 1 ), and subsequently spent approximately 20 minutes obtaining in situ images and video. Size estimates were obtained using a bottom mapping camera and two parallel line lasers spaced 62 cm apart. Finally, a small branch voucher specimen of the colony was collected with manipulator for further investigation, and once shipboard preserved in 99% ethanol (specimen number JAMSTEC No. 106647, onboard ID KM#130-CN-03a). DNA extraction of the antipatharian specimen was performed using a DNeasy Blood and Tissue kit (Qiagen, Tokyo, Japan) following the manufacturer’s instructions. We subsequently amplified the mitochondrial DNA marker IgrN using primers ND5-51anti10725F (5’-CACACTTGGTTGCCGGATGCTATG-3’) and ND1anti11217R (5’-CCTAAAACCTTNCGTTCRGCTAAAGTT3’) (Thoma et al. 2009 ). PCR was performed using HotStarMasterMix (Qiagen, Tokyo, Japan) under the following conditions: incubation at 94°C for 15 minutes; 35 x cycles of 30 seconds at 94°C, 30 seconds at 53°C, 40 seconds at 72°C; and a final extension of 6 minutes at 72°C. We also amplified mitochondrial IgrW using primers TRPntiF (5’-GGAAGACCGTTAGCCTTC-3’) and ND2anti1040R (5’-CCAAATAAGAATAAGCCTGAAG-3’) (Thoma et al. 2009 ). Amplification was performed using Taq Mastermix (Qiagen, Tokyo, Japan) under the following PCR conditions: 2 minutes incubation at 94°C; 35 cycles of 1.5 minutes at 94°C, 1.5 minutes at 55°C, 1 minute at 72°C, and a final extension of 5 minutes at 72°C. PCR products were purified using Shrimp Alkaline Phosphatase (SAP) and E . coli Exonuclease (ExoI) (Takara Bio Inc., Shiga, Japan) following the manufacturer’s protocol. Purified PCR products were sent for sequencing in both directions to Fasmac (Kanagawa). Results and Discussion The single, very large antipatharian colony was observed at a depth of 525 m and was initially identified as a Leiopathes sp. based on external appearance including coloration. The colony was growing on the ridge of the seamount. Exact location and other detailed information are available upon reasonable request from the corresponding author. From our video analyses, the dimensions of the colony were estimated as a height of approximately 308 cm, a width of approximately 441 cm, and a basal trunk diameter of approximately 27.9 cm. On this Leiopathes colony we observed the spikefish Triacanthodes anomalus, Physiculus rhodopinnis , and the abyssal cutthroat eel Meadia abyssalis . We also confirmed the presence of numerous invertebrate species, including epibionts such as the king crab Paralomis kyushupalauensis , spider crab Samadinia sp., basket star Gorgonocephalus eucnemis , and the brittle star Ophiacanthidae gen. sp. We also observed sponge Hexactinellida spp., unidentified Cnidaria spp., squat lobster Eumunida spp., spiny deep-sea spider crab Cyrtomaia micronesica , and sea urchin Echinoidea spp. in the immediate area around the colony. Additionally, the channeled rockfish Setarches guentheri , roughy Hoplostethus sp., and deepwater cardinalfish Epigonus sp. were noted in the vicinity. While we observed other antipatharian colonies of similar branching pattern and form that were likely conspecific Leiopathes , we did not observe any other colony of similar extraordinarily large size during the KM20-10 research cruise. Based on our molecular sequencing results (GenBank accession number XXXX for IgrN , XXXX for IgrW ), we confirmed the identity of the colony as Leiopathes cf. glaberrima , as the sequences of both markers matched 100% with previously reported sequences of Leiopathes glaberrima and other Leiopathes species [GenBank Accession Numbers on ND5 sequences: KF013041 (Ruiz-Ramos et al. 2015 ), MT318846-8 (Barret et al. 2020), KF054669 (Brugler et al. 2013 )]. Large anthozoan colonies often host a diverse assemblage of associated organisms, and the Leiopathes cf. glaberrima we observed is no exception, and can be considered an important ecosystem engineer on this seamount. As the Ministry of Environment of Japan has designated this oceanic region as a marine protected area from 2020, and given that data on deep-sea cnidarians in the northwestern Pacific can be considered very scarce (Reimer et al. 2021 ), it is clear that more data are needed to properly inform conservation efforts. Growth rates of deep-sea anthozoans such as Leiopathes have been the focus of much research, with wide ranges reported based on the methodologies employed (Roark et al. 2006 ; 2009 ). Based on work using stable isotope analyses, Roark et al. ( 2009 ) estimated radial growth rates as between < 5 to 13 µm per year in Leiopathes glaberrima from Hawaii, while noting that their analyses only examined branches and the upper range, stating that lifespans may be much higher. Similar work for Leiopathes sp. from the Gulf of Mexico estimated growth rates of 8 to 22 µm per year (Prouty et al. 2011 ). Even with a relatively conservatively fast growth rate estimate of 20 µm per year, and if this large L. cf. glaberrima colony we observed has grown in radial fashion, the age of our observed colony can be estimated at approximately 7,000 years old (diameter = 27.9 cm, radius = 13.95 cm/20 µm per year). This is far older than previous longevity estimates of anthozoans, such as 2,100 years for Leiopathes in the Gulf of Mexico (Prouty et al. 2011 ), and 2,742 years for the Hawaiian gold coral Kulamanamana haumeaae and 4,265 years for L . glaberrima in Hawaii (both Roark et al. 2009 ). Among other marine organisms, clonal organism such as some seagrass species may have lifespans of hundreds to thousands of years (Reusch et al. 1999 ; Arnaud-Haond et al. 2007 ). Unfortunately, confirmation of the age of the current L. cf. glaberrima colony would require invasive sampling, but at the least given its extreme size we can consider it possible that this colony may be among the oldest living organisms on Earth. Such extreme lifespans counter the argument that these colonies represent renewable bioresources (Roark et al. 2009 ), and it is hoped this report spurs concerted conservation efforts for this seamount. Declarations Acknowledgements : We thank the captain and crew of R/V Kaimei (JAMSTEC), as well as the operation team of KM-ROV for their support in observation and specimen collection. Leg 2 of cruise KM20-10C was funded by an MPA monitoring project outsourced by the Ministry of the Environment of Japan. This research was partly supported by the Environment Research and Technology Development Fund (JPMEERF20S20700) of the Environmental Restoration and Conservation Agency provided by the Ministry of Environment of Japan. We thank Dr. Tony Montgomery (USFWS) for consultation on Leiopathes growth rates. Compliance with ethical standards: Ethical approval was obtained by JAMSTEC’s research safety committee, and limit control standards of Fisheries Agency of Japan were followed. Data availability statement: The image data associated with this cruise are available upon reasonable request from the corresponding author . DNA sequence data are deposited in GenBank as detailed in the text above. References Arnaud‐Haond S, Migliaccio M, Diaz‐Almela E, Teixeira S, Van De Vliet MS, Alberto F, Procaccini G, Duarte CM, Serrao EA. 2007. Vicariance patterns in the Mediterranean Sea: east–west cleavage and low dispersal in the endemic seagrass Posidonia oceanica . Journal of Biogeography 34:963-76 Barrett NJ, Hogan RI, Allcock AL, Molodtsova T, Hopkins K, Wheeler AJ, Yesson C. 2020. Phylogenetics and mitogenome organisation in black corals (Anthozoa: Hexacorallia: Antipatharia): an order-wide survey inferred from complete mitochondrial genomes. Frontiers in Marine Science 7:440 Bo M, Coppari M, Betti F, Enrichetti F, Bertolino M, Massa F, Bava S, Gay G, Cattaneo‐Vietti R, Bavestrello G. 2021. The high biodiversity and vulnerability of two Mediterranean bathyal seamounts support the need for creating offshore protected areas. Aquatic Conservation: Marine and Freshwater Ecosystems 31:543-66 Brugler MR, Opresko DM, France SC. 2013. The evolutionary history of the order Antipatharia (Cnidaria: Anthozoa: Hexacorallia) as inferred from mitochondrial and nuclear DNA: implications for black coral taxonomy and systematics. Zoological Journal of the Linnean Society 169:312-61 Morato T, Hoyle SD, Allain V, Nicol SJ. 2010. Seamounts are hotspots of pelagic biodiversity in the open ocean. Proceedings of the National Academy of Sciences 107:9707-11 Prouty NG, Roark EB, Buster NA, Ross SW. 2011. Growth rate and age distribution of deep-sea black corals in the Gulf of Mexico. Marine Ecology Progress Series 423:101-15 Reimer JD, Yanagi K, Kise H, Poliseno A, Kushida Y, Saeedi H, Lindsay DJ. 2021. Review of deep-sea Cnidaria and Ctenophora fauna in the NW Pacific Ocean. In: Biogeographic Atlas of the Deep NW Pacific Fauna 67-88 Reusch TBH, Bostrom C, Stam WT, Olsen JL. 1999. An ancient eelgrass clone in the Baltic. Marine Ecology Progress Series 183:301-4 Roark EB, Guilderson TP, Dunbar RB, Ingram BL. 2006. Radiocarbon-based ages and growth rates of Hawaiian deep-sea corals. Marine Ecology Progress Series 327:1-4 Roark EB, Guilderson TP, Dunbar RB, Fallon SJ, Mucciarone DA. 2009. Extreme longevity in proteinaceous deep-sea corals. Proceedings of the National Academy of Sciences 106:5204-8 Rossi S, Bramanti L, Horta P, Allcock L, Carreiro-Silva M, Coppari M, Denis V, Hadjioannou L, Isla E, Jimenez C, Johnson M, et al. 2022. Protecting global marine animal forests. Science 376:929 Rowden AA, Clark MR, O’Shea S, McKnight DG. 2003. Benthic biodiversity of seamounts on the southern Kermadec volcanic arc. Marine Biodiversity Biosecurity Report 3:1-23 Ruiz-Ramos DV, Saunders M, Fisher CR, Baums IB. 2015. Home bodies and wanderers: Sympatric lineages of the deep-sea black coral Leiopathes glaberrima . PLoS One 10:e0138989 Sinniger F, Ocana OV, Baco AR. 2013. Diversity of zoanthids (Anthozoa: Hexacorallia) on Hawaiian seamounts: description of the Hawaiian gold coral and additional zoanthids. PloS One 8:e52607 . Thoma JN, Pante E, Brugler MR, France SC. 2009. Deep-sea octocorals and antipatharians show no evidence of seamount-scale endemism in the NW Atlantic. Marine Ecology Progress Series 397:25–35 Supplementary Files Genbanknumbers.docx Cite Share Download PDF Status: Published Journal Publication published 23 Oct, 2024 Read the published version in Marine Biodiversity → Version 1 posted Editorial decision: Major Revisions Needed 07 Jul, 2024 Reviewers agreed at journal 22 May, 2024 Reviewers invited by journal 21 May, 2024 Editor invited by journal 21 May, 2024 Editor assigned by journal 18 Mar, 2024 First submitted to journal 17 Mar, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4116139","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":305151335,"identity":"eeea3e75-16b7-43cf-af39-79c0b8e3ce2a","order_by":0,"name":"James Davis 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\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) and often harbor rich benthic communities (Rowden et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). Among benthic organisms, many reports have documented large and rich communities of anthozoans at seamounts around the world (Sinniger et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Bo et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). As ecosystem engineers, anthozoans form the intricate foundation for diverse benthic communities, and as such have often been focused on in much research while discussing the need for their conservation (Bo et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Indeed, the conservation of these \u0026ldquo;marine animal forests\u0026rdquo; (MAFs) are of urgent importance (Rossi et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDuring a recent deep-sea research cruise aiming at characterizing the seamounts of the Nishi-Shichito and of the central and western Mariana ridges, we observed and recorded the fauna of Shotoku, Ritto, and Nikko seamounts. Among our observations, we recorded and investigated an extraordinarily large antipatharian colony, and here report on this unique observation.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eLeg 2 of the Japan Agency for Marine Science and Technology (JAMSTEC) research cruise KM20-10C aboard the R/V \u003cem\u003eKaimei\u003c/em\u003e investigated the seamounts of the Nishi-Shichito and central and western Mariana ridges from December 2 to December 12, 2020 via observations and specimen collection utilizing the remotely operated vehicle \u003cem\u003eKM-ROV\u003c/em\u003e. During dive \u003cem\u003eKM-ROV\u003c/em\u003e#130 on December 5, 2020 at Ritto Seamount, we observed an extraordinarily large colony of antipatharian (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), and subsequently spent approximately 20 minutes obtaining in situ images and video. Size estimates were obtained using a bottom mapping camera and two parallel line lasers spaced 62 cm apart. Finally, a small branch voucher specimen of the colony was collected with manipulator for further investigation, and once shipboard preserved in 99% ethanol (specimen number JAMSTEC No. 106647, onboard ID KM#130-CN-03a).\u003c/p\u003e \u003cp\u003eDNA extraction of the antipatharian specimen was performed using a DNeasy Blood and Tissue kit (Qiagen, Tokyo, Japan) following the manufacturer\u0026rsquo;s instructions. We subsequently amplified the mitochondrial DNA marker \u003cem\u003eIgrN\u003c/em\u003e using primers ND5-51anti10725F (5\u0026rsquo;-CACACTTGGTTGCCGGATGCTATG-3\u0026rsquo;) and ND1anti11217R (5\u0026rsquo;-CCTAAAACCTTNCGTTCRGCTAAAGTT3\u0026rsquo;) (Thoma et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). PCR was performed using HotStarMasterMix (Qiagen, Tokyo, Japan) under the following conditions: incubation at 94\u0026deg;C for 15 minutes; 35 x cycles of 30 seconds at 94\u0026deg;C, 30 seconds at 53\u0026deg;C, 40 seconds at 72\u0026deg;C; and a final extension of 6 minutes at 72\u0026deg;C. We also amplified mitochondrial \u003cem\u003eIgrW\u003c/em\u003e using primers TRPntiF (5\u0026rsquo;-GGAAGACCGTTAGCCTTC-3\u0026rsquo;) and ND2anti1040R (5\u0026rsquo;-CCAAATAAGAATAAGCCTGAAG-3\u0026rsquo;) (Thoma et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Amplification was performed using Taq Mastermix (Qiagen, Tokyo, Japan) under the following PCR conditions: 2 minutes incubation at 94\u0026deg;C; 35 cycles of 1.5 minutes at 94\u0026deg;C, 1.5 minutes at 55\u0026deg;C, 1 minute at 72\u0026deg;C, and a final extension of 5 minutes at 72\u0026deg;C. PCR products were purified using Shrimp Alkaline Phosphatase (SAP) and \u003cem\u003eE\u003c/em\u003e. \u003cem\u003ecoli\u003c/em\u003e Exonuclease (ExoI) (Takara Bio Inc., Shiga, Japan) following the manufacturer\u0026rsquo;s protocol. Purified PCR products were sent for sequencing in both directions to Fasmac (Kanagawa).\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cp\u003eThe single, very large antipatharian colony was observed at a depth of 525 m and was initially identified as a \u003cem\u003eLeiopathes\u003c/em\u003e sp. based on external appearance including coloration. The colony was growing on the ridge of the seamount. Exact location and other detailed information are available upon reasonable request from the corresponding author. From our video analyses, the dimensions of the colony were estimated as a height of approximately 308 cm, a width of approximately 441 cm, and a basal trunk diameter of approximately 27.9 cm. On this \u003cem\u003eLeiopathes\u003c/em\u003e colony we observed the spikefish \u003cem\u003eTriacanthodes anomalus, Physiculus rhodopinnis\u003c/em\u003e, and the abyssal cutthroat eel \u003cem\u003eMeadia abyssalis\u003c/em\u003e. We also confirmed the presence of numerous invertebrate species, including epibionts such as the king crab \u003cem\u003eParalomis kyushupalauensis\u003c/em\u003e, spider crab \u003cem\u003eSamadinia\u003c/em\u003e sp., basket star \u003cem\u003eGorgonocephalus eucnemis\u003c/em\u003e, and the brittle star Ophiacanthidae gen. sp. We also observed sponge Hexactinellida spp., unidentified Cnidaria spp., squat lobster \u003cem\u003eEumunida\u003c/em\u003e spp., spiny deep-sea spider crab \u003cem\u003eCyrtomaia micronesica\u003c/em\u003e, and sea urchin Echinoidea spp. in the immediate area around the colony. Additionally, the channeled rockfish \u003cem\u003eSetarches guentheri\u003c/em\u003e, roughy \u003cem\u003eHoplostethus\u003c/em\u003e sp., and deepwater cardinalfish \u003cem\u003eEpigonus\u003c/em\u003e sp. were noted in the vicinity. While we observed other antipatharian colonies of similar branching pattern and form that were likely conspecific \u003cem\u003eLeiopathes\u003c/em\u003e, we did not observe any other colony of similar extraordinarily large size during the KM20-10 research cruise.\u003c/p\u003e \u003cp\u003eBased on our molecular sequencing results (GenBank accession number XXXX for \u003cem\u003eIgrN\u003c/em\u003e, XXXX for \u003cem\u003eIgrW\u003c/em\u003e), we confirmed the identity of the colony as \u003cem\u003eLeiopathes\u003c/em\u003e cf. \u003cem\u003eglaberrima\u003c/em\u003e, as the sequences of both markers matched 100% with previously reported sequences of \u003cem\u003eLeiopathes glaberrima\u003c/em\u003e and other \u003cem\u003eLeiopathes\u003c/em\u003e species [GenBank Accession Numbers on ND5 sequences: KF013041 (Ruiz-Ramos et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), MT318846-8 (Barret et al. 2020), KF054669 (Brugler et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2013\u003c/span\u003e)].\u003c/p\u003e \u003cp\u003eLarge anthozoan colonies often host a diverse assemblage of associated organisms, and the \u003cem\u003eLeiopathes\u003c/em\u003e cf. \u003cem\u003eglaberrima\u003c/em\u003e we observed is no exception, and can be considered an important ecosystem engineer on this seamount. As the Ministry of Environment of Japan has designated this oceanic region as a marine protected area from 2020, and given that data on deep-sea cnidarians in the northwestern Pacific can be considered very scarce (Reimer et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), it is clear that more data are needed to properly inform conservation efforts.\u003c/p\u003e \u003cp\u003eGrowth rates of deep-sea anthozoans such as \u003cem\u003eLeiopathes\u003c/em\u003e have been the focus of much research, with wide ranges reported based on the methodologies employed (Roark et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Based on work using stable isotope analyses, Roark et al. (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2009\u003c/span\u003e) estimated radial growth rates as between \u0026lt;\u0026thinsp;5 to 13 \u0026micro;m per year in \u003cem\u003eLeiopathes glaberrima\u003c/em\u003e from Hawaii, while noting that their analyses only examined branches and the upper range, stating that lifespans may be much higher. Similar work for \u003cem\u003eLeiopathes\u003c/em\u003e sp. from the Gulf of Mexico estimated growth rates of 8 to 22 \u0026micro;m per year (Prouty et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Even with a relatively conservatively fast growth rate estimate of 20 \u0026micro;m per year, and if this large \u003cem\u003eL.\u003c/em\u003e cf. \u003cem\u003eglaberrima\u003c/em\u003e colony we observed has grown in radial fashion, the age of our observed colony can be estimated at approximately 7,000 years old (diameter\u0026thinsp;=\u0026thinsp;27.9 cm, radius\u0026thinsp;=\u0026thinsp;13.95 cm/20 \u0026micro;m per year). This is far older than previous longevity estimates of anthozoans, such as 2,100 years for \u003cem\u003eLeiopathes\u003c/em\u003e in the Gulf of Mexico (Prouty et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2011\u003c/span\u003e), and 2,742 years for the Hawaiian gold coral \u003cem\u003eKulamanamana haumeaae\u003c/em\u003e and 4,265 years for \u003cem\u003eL\u003c/em\u003e. \u003cem\u003eglaberrima\u003c/em\u003e in Hawaii (both Roark et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Among other marine organisms, clonal organism such as some seagrass species may have lifespans of hundreds to thousands of years (Reusch et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e1999\u003c/span\u003e; Arnaud-Haond et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). Unfortunately, confirmation of the age of the current \u003cem\u003eL.\u003c/em\u003e cf. \u003cem\u003eglaberrima\u003c/em\u003e colony would require invasive sampling, but at the least given its extreme size we can consider it possible that this colony may be among the oldest living organisms on Earth. Such extreme lifespans counter the argument that these colonies represent renewable bioresources (Roark et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2009\u003c/span\u003e), and it is hoped this report spurs concerted conservation efforts for this seamount.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e:\u003c/p\u003e\n\u003cp\u003eWe thank the captain and crew of R/V \u003cem\u003eKaimei\u003c/em\u003e (JAMSTEC), as well as the operation team of \u003cem\u003eKM-ROV\u003c/em\u003e for their support in observation and specimen collection. Leg 2 of cruise KM20-10C was funded by an MPA monitoring project outsourced by the Ministry of the Environment of Japan. This research was partly supported by the Environment Research and Technology Development Fund (JPMEERF20S20700) of the Environmental Restoration and Conservation Agency provided by the Ministry of Environment of Japan. We thank Dr. Tony Montgomery (USFWS) for consultation on \u003cem\u003eLeiopathes\u003c/em\u003e growth rates.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompliance with ethical standards:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical approval was obtained by JAMSTEC’s research safety committee, and limit control standards of Fisheries Agency of Japan were followed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statement:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe image data associated with this cruise are available upon reasonable request from the corresponding author . DNA sequence data are deposited in GenBank as detailed in the text above.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eArnaud‐Haond S, Migliaccio M, Diaz‐Almela E, Teixeira S, Van De Vliet MS, Alberto F, Procaccini G, Duarte CM, Serrao EA. 2007. Vicariance patterns in the Mediterranean Sea: east\u0026ndash;west cleavage and low dispersal in the endemic seagrass \u003cem\u003ePosidonia oceanica\u003c/em\u003e. Journal of Biogeography 34:963-76\u003c/li\u003e\n\u003cli\u003eBarrett NJ, Hogan RI, Allcock AL, Molodtsova T, Hopkins K, Wheeler AJ, Yesson C. 2020. Phylogenetics and mitogenome organisation in black corals (Anthozoa: Hexacorallia: Antipatharia): an order-wide survey inferred from complete mitochondrial genomes. Frontiers in Marine Science 7:440\u003c/li\u003e\n\u003cli\u003eBo M, Coppari M, Betti F, Enrichetti F, Bertolino M, Massa F, Bava S, Gay G, Cattaneo‐Vietti R, Bavestrello G. 2021. The high biodiversity and vulnerability of two Mediterranean bathyal seamounts support the need for creating offshore protected areas. Aquatic Conservation: Marine and Freshwater Ecosystems 31:543-66\u003c/li\u003e\n\u003cli\u003eBrugler MR, Opresko DM, France SC. 2013. The evolutionary history of the order Antipatharia (Cnidaria: Anthozoa: Hexacorallia) as inferred from mitochondrial and nuclear DNA: implications for black coral taxonomy and systematics. Zoological Journal of the Linnean Society 169:312-61\u003c/li\u003e\n\u003cli\u003eMorato T, Hoyle SD, Allain V, Nicol SJ. 2010. Seamounts are hotspots of pelagic biodiversity in the open ocean. Proceedings of the National Academy of Sciences 107:9707-11\u003c/li\u003e\n\u003cli\u003eProuty NG, Roark EB, Buster NA, Ross SW. 2011. Growth rate and age distribution of deep-sea black corals in the Gulf of Mexico. Marine Ecology Progress Series 423:101-15\u003c/li\u003e\n\u003cli\u003eReimer JD, Yanagi K, Kise H, Poliseno A, Kushida Y, Saeedi H, Lindsay DJ. 2021. Review of deep-sea Cnidaria and Ctenophora fauna in the NW Pacific Ocean. In: Biogeographic Atlas of the Deep NW Pacific Fauna 67-88\u003c/li\u003e\n\u003cli\u003eReusch TBH, Bostrom C, Stam WT, Olsen JL. 1999. An ancient eelgrass clone in the Baltic. Marine Ecology Progress Series 183:301-4\u003c/li\u003e\n\u003cli\u003eRoark EB, Guilderson TP, Dunbar RB, Ingram BL. 2006. Radiocarbon-based ages and growth rates of Hawaiian deep-sea corals. Marine Ecology Progress Series 327:1-4\u003c/li\u003e\n\u003cli\u003eRoark EB, Guilderson TP, Dunbar RB, Fallon SJ, Mucciarone DA. 2009. Extreme longevity in proteinaceous deep-sea corals. Proceedings of the National Academy of Sciences 106:5204-8\u003c/li\u003e\n\u003cli\u003eRossi S, Bramanti L, Horta P, Allcock L, Carreiro-Silva M, Coppari M, Denis V, Hadjioannou L, Isla E, Jimenez C, Johnson M, et al. 2022. Protecting global marine animal forests. Science 376:929\u003c/li\u003e\n\u003cli\u003eRowden AA, Clark MR, O\u0026rsquo;Shea S, McKnight DG. 2003. Benthic biodiversity of seamounts on the southern Kermadec volcanic arc. Marine Biodiversity Biosecurity Report 3:1-23\u003c/li\u003e\n\u003cli\u003eRuiz-Ramos DV, Saunders M, Fisher CR, Baums IB. 2015. Home bodies and wanderers: Sympatric lineages of the deep-sea black coral \u003cem\u003eLeiopathes glaberrima\u003c/em\u003e. PLoS One 10:e0138989\u003c/li\u003e\n\u003cli\u003eSinniger F, Ocana OV, Baco AR. 2013. Diversity of zoanthids (Anthozoa: Hexacorallia) on Hawaiian seamounts: description of the Hawaiian gold coral and additional zoanthids. PloS One 8:e52607 .\u003c/li\u003e\n\u003cli\u003eThoma JN, Pante E, Brugler MR, France SC. 2009. Deep-sea octocorals and antipatharians show no evidence of seamount-scale endemism in the NW Atlantic. Marine Ecology Progress Series 397:25\u0026ndash;35\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"marine-biodiversity","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"marb","sideBox":"Learn more about [Marine Biodiversity](http://link.springer.com/journal/12526)","snPcode":"12526","submissionUrl":"https://www.editorialmanager.com/marb/default2.aspx","title":"Marine Biodiversity","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Antipatharia, Anthozoa, Cnidaria, Nishi-Shichito Ridge, Ritto Seamount","lastPublishedDoi":"10.21203/rs.3.rs-4116139/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4116139/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAnthozoans are ecosystem engineers and contribute to creating intricate benthic communities that often harbor high levels of marine biodiversity. Here, we report on an extraordinarily large antipatharian colony observed on the Ritto Seamount in the Northwest Pacific. Based on colony form and DNA barcoding results, we identified the colony as \u003cem\u003eLeiopathes\u003c/em\u003e cf. \u003cem\u003eglaberrima\u003c/em\u003e. From in situ observations, we estimate the size of the colony as approximately 308 cm in height, 441 cm in width, with a central stem of 27.9 cm in diameter. If growth rates of \u003cem\u003eLeiopathes\u003c/em\u003e species in this region of the Pacific Ocean are similar to those previously reported from Hawai\u0026rsquo;i, this colony may potentially be approximately several thousand years old, placing it among the longest-lived marine organisms reported. Seamounts in this region and such large antipatharians and other anthozoan colonies should be targeted for more biodiversity investigation and future conservation.\u003c/p\u003e","manuscriptTitle":"A massive and potentially ancient antipatharian colony at a seamount in the Northwest Pacific","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-03 17:01:53","doi":"10.21203/rs.3.rs-4116139/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major Revisions Needed","date":"2024-07-07T05:21:00+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2024-05-22T22:14:41+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-05-21T17:37:43+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Marine Biodiversity","date":"2024-05-21T17:24:39+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-03-19T03:31:26+00:00","index":"","fulltext":""},{"type":"submitted","content":"Marine Biodiversity","date":"2024-03-17T04:54:32+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"marine-biodiversity","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"marb","sideBox":"Learn more about [Marine Biodiversity](http://link.springer.com/journal/12526)","snPcode":"12526","submissionUrl":"https://www.editorialmanager.com/marb/default2.aspx","title":"Marine Biodiversity","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"833fb99f-bbb6-4644-9fc7-ee7dd16bf838","owner":[],"postedDate":"June 3rd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-10-28T16:02:29+00:00","versionOfRecord":{"articleIdentity":"rs-4116139","link":"https://doi.org/10.1007/s12526-024-01478-w","journal":{"identity":"marine-biodiversity","isVorOnly":false,"title":"Marine Biodiversity"},"publishedOn":"2024-10-23 15:57:42","publishedOnDateReadable":"October 23rd, 2024"},"versionCreatedAt":"2024-06-03 17:01:53","video":"","vorDoi":"10.1007/s12526-024-01478-w","vorDoiUrl":"https://doi.org/10.1007/s12526-024-01478-w","workflowStages":[]},"version":"v1","identity":"rs-4116139","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4116139","identity":"rs-4116139","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}