Menthol-DCMU bleaching and re-inoculation experiments with different diatom strains provide evidence of symbiont switching in benthic foraminifera

Menthol-DCMU bleaching and re-inoculation experiments with different diatom strains provide evidence of symbiont switching in benthic foraminifera | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Menthol-DCMU bleaching and re-inoculation experiments with different diatom strains provide evidence of symbiont switching in benthic foraminifera Diana Puerto Rueda, Marleen Stuhr, Maoz Fine, Christiane Schmidt This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7215226/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Marine heat waves are increasing in frequency, highlighting the urgent need to understand the thermal resilience and symbiont-switching potential of non-coral calcifiers such as large benthic foraminifera (LBF), important calcium carbonate producers and sediment generators in coral reefs. This study investigates the potential for symbiont-switching to enhance thermal resilience in the diatom-bearing foraminifer Amphistegina lobifera by conducting a controlled bleaching and re-inoculation experiment. A 4-week menthol-DCMU bleaching protocol was used to generate aposymbiotic hosts, followed by a 10-day re-inoculation experiment with three diatom strains: Nitzschia spp., Fragilaria spp. (both native to A. lobifera), and Minutocellus spp. (native to the thermally resilient Pararotalia calcariformata). Re-inoculation success was assessed by symbiont coverage (% surface area occupied by the symbiont via confocal laser scanning microscopy) and photosynthetic efficiency (Fv:Fm using pulse-amplitude modulated fluorometry). All specimens exhibited increased photosynthetic efficiency. Symbiont coverage increased by 67–102% for Fragilaria spp. and 22–108% for Nitzschia spp., with half of the individuals fully re-browning. Minutocellus spp. reached >85% coverage in two individuals and ~7% in others. These results demonstrate that A. lobifera can establish new symbioses with non-native symbionts, suggesting symbiont-switching as a viable strategy for thermal adaptation under ocean warming. Biological sciences/Ecology/Microbial ecology Earth and environmental sciences/Ocean sciences/Marine biology Biological sciences/Ecology/Ecophysiology Symbiont plasticity Large benthic foraminifera holobiont symbiosis assisted evolution ocean warmi Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Posted Version 1 posted 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. 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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-7215226","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":497746365,"identity":"4367f7b2-88f5-4453-b928-a0c48497e695","order_by":0,"name":"Diana Puerto Rueda","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABRElEQVRIie3RMWuDQBQH8CeCXQ67Ktb2K1wQLCX9MIrQLkkIFEq2mqWTxK3o0n4Fu2Qq5IJQF4NrihnMclOGTiEUoVWbDGrtXKj/xfO9+91TDqBNm78Yv1YhLAHAoAGg4p0xGwl7IJz2OyF1gnD+aCR8wNJkByvdlqJ5wrz4p3wQbqXhEAbHD4tXafQBsl0mos+ddyygujsxWAzUV8SwP5UcDDdCPLgSFxNQ3PIY7IMqIPB1L2Q5AUi2IBlB+FM3454qji3IKhVytBXTjMz25M6LNjQjoD8dyKxKkCoVU9A30fCyxxXEy4m5yxbVf0G30gmmihOyCtbIdcddUqWbk+d4YFyMTUFxylP4KJiKm9FKti1mnbyT7hkfGesYpaA/xv35m5leynb1YorP25+j1TrMvfDD/jykoQ6QNnbatGnT5t/kC5t2fUq4m9WwAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0009-0000-3647-1099","institution":"Institute of Marine Ecosystem and Fishery Science","correspondingAuthor":true,"prefix":"","firstName":"Diana","middleName":"Puerto","lastName":"Rueda","suffix":""},{"id":497746366,"identity":"fb11cf8d-9ddf-4d56-b27b-d868f8ef5353","order_by":1,"name":"Marleen Stuhr","email":"","orcid":"https://orcid.org/0000-0001-9155-9464","institution":"Leibniz Centre for Tropical Marine Research (ZMT)","correspondingAuthor":false,"prefix":"","firstName":"Marleen","middleName":"","lastName":"Stuhr","suffix":""},{"id":497746367,"identity":"f582edbe-fe46-4ca7-a62e-f3b37f4c85b3","order_by":2,"name":"Maoz Fine","email":"","orcid":"","institution":"Interuniversity Institute for Marine Sciences in Eilat","correspondingAuthor":false,"prefix":"","firstName":"Maoz","middleName":"","lastName":"Fine","suffix":""},{"id":497746368,"identity":"c5588d93-097c-4357-a7d8-060ab874a8eb","order_by":3,"name":"Christiane Schmidt","email":"","orcid":"","institution":"Helmholtz Centre Potsdam","correspondingAuthor":false,"prefix":"","firstName":"Christiane","middleName":"","lastName":"Schmidt","suffix":""}],"badges":[],"createdAt":"2025-07-25 14:35:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7215226/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7215226/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109119445,"identity":"a720b0b5-2117-4eb4-a70f-504e621a142c","added_by":"auto","created_at":"2026-05-12 16:58:00","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":502490,"visible":true,"origin":"","legend":"Article File","description":"","filename":"MentholDCMUbleachingandreinoculationexperimentswithdifferentdiatomstrainsprovideevidenceofsymbiontswitchinginbenthicforaminifera.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7215226/v1_covered_7ca9aa58-c79d-4cc1-a708-29060389b47e.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Menthol-DCMU bleaching and re-inoculation experiments with different diatom strains provide evidence of symbiont switching in benthic foraminifera","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Symbiont plasticity, Large benthic foraminifera, holobiont, symbiosis, assisted evolution, ocean warmi","lastPublishedDoi":"10.21203/rs.3.rs-7215226/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7215226/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Marine heat waves are increasing in frequency, highlighting the urgent need to understand the thermal resilience and symbiont-switching potential of non-coral calcifiers such as large benthic foraminifera (LBF), important calcium carbonate producers and sediment generators in coral reefs. This study investigates the potential for symbiont-switching to enhance thermal resilience in the diatom-bearing foraminifer Amphistegina lobifera by conducting a controlled bleaching and re-inoculation experiment. A 4-week menthol-DCMU bleaching protocol was used to generate aposymbiotic hosts, followed by a 10-day re-inoculation experiment with three diatom strains: Nitzschia spp., Fragilaria spp. (both native to A. lobifera), and Minutocellus spp. (native to the thermally resilient Pararotalia calcariformata). Re-inoculation success was assessed by symbiont coverage (% surface area occupied by the symbiont via confocal laser scanning microscopy) and photosynthetic efficiency (Fv:Fm using pulse-amplitude modulated fluorometry). All specimens exhibited increased photosynthetic efficiency. Symbiont coverage increased by 67–102% for Fragilaria spp. and 22–108% for Nitzschia spp., with half of the individuals fully re-browning. Minutocellus spp. reached \u003e85% coverage in two individuals and ~7% in others. These results demonstrate that A. lobifera can establish new symbioses with non-native symbionts, suggesting symbiont-switching as a viable strategy for thermal adaptation under ocean warming.","manuscriptTitle":"Menthol-DCMU bleaching and re-inoculation experiments with different diatom strains provide evidence of symbiont switching in benthic foraminifera","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-11 19:12:04","doi":"10.21203/rs.3.rs-7215226/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"0b982cdf-e1fd-4eef-9232-edc4b1c094dc","owner":[],"postedDate":"September 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":52878183,"name":"Biological sciences/Ecology/Microbial ecology"},{"id":52878184,"name":"Earth and environmental sciences/Ocean sciences/Marine biology"},{"id":52878185,"name":"Biological sciences/Ecology/Ecophysiology"}],"tags":[],"updatedAt":"2026-05-12T16:57:41+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-11 19:12:04","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7215226","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7215226","identity":"rs-7215226","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}