867f94ab-21a9-4c2b-8dbe-9de5dade0cb7 Andrea Tarallo National Research Council (CNR), Institute of Research on Terrestrial Ecosystems (IRET) Technologist andrea.tarallo@cnr.it 0000-0002-2749-8588 Serena Rasconi Université Savoie Mont Blanc Researcher Serena.Rasconi@gmail.com 0000-0001-6667-8904 Albert Reñé Institut de Ciències del Mar Researcher 0000-0002-0488-3539 Alena Gsell University of Leiden Professor (Assistant) 0000-0001-7795-1996 Alexandra Kraberg Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Researcher 0000-0003-2571-2074 Katelyn McKindles Baylor University Assistant Professor kmckindl@gmail.com 0000-0002-6352-0375 Silke Van den Wyngaert University of Turku Researcher silke.vandenwyngaert@utu.fi 0000-0001-9163-4858 Ilaria Rosati National Research Council (CNR), Institute of Research on Terrestrial Ecosystems (IRET) Technologist ilaria.rosati@cnr.it 0000-0003-3422-7230 Andrea Tarallo Andrea Tarallo National Research Council (CNR), Institute of Research on Terrestrial Ecosystems (IRET) Technologist andrea.tarallo@cnr.it 0000-0002-2749-8588 Ilaria Rosati National Research Council (CNR), Institute of Research on Terrestrial Ecosystems (IRET) Technologist ilaria.rosati@cnr.it 0000-0003-3422-7230 Custodian Steward 2026-03-04 English Zoosporic parasites play crucial ecological roles in aquatic environments, influencing algal population dynamics, nutrient cycling, and energy transfer within microbial food webs. Despite their importance, data on their diversity, distribution, and interactions with primary producers remain sparse and fragmented. Here, we present a harmonised dataset of field observations on zoosporic parasites infecting aquatic primary producers. The dataset integrates both published and previously unpublished records, encompassing more than 4,400 observations collected between 2007 and 2022 across 28 sites in Europe and North America. It includes data for 91 unique parasite taxa, along with confirmed and putative parasite–host associations derived from direct microscopic or molecular evidence. All records were standardised using the Darwin Core schema to ensure interoperability and long-term usability. This open-access resource provides a foundation for comparative and meta-analytical studies on parasite–host ecology, biodiversity assessments, and industrial applications related to algal production systems. algae fungi eLTER Controlled Lists diatoms phytoplankton cyanobacteria macroalgae host-parasite interaction Environmental Thesaurus Occurrence Parasitism Alien Species Thesaurus cc-by https://creativecommons.org/licenses/by/4.0/ The geographic distribution of the dataset is defined by a bounding box ranging from latitude 59.92 to longitude -84.51. The collected samples originate from 28 unique locations across seven countries: Finland (n = 4 observations), France (n = 990 observations), Germany (n = 1517 observations), the Netherlands (n = 505 observations), Spain (n = 34 observations), the United Kingdom (n = 1350 observations), and the USA (n = 27 observations). -84.50989 20.9097222 59.9208333 39.3296944 1197 0 meter 2007-01-17 2021-11-03 The dataset encompasses 91 unique taxa. The lowest determined taxonomic rank varied among records. The taxonomic description includes 44 taxa identified at the species level, 14 at the genus level, 3 at the family level, 29 at the order level, and 1 unidentified fungal taxon not assignable to any known fungal phylum. Species Algomyces stechlinensis https://www.checklistbank.org/dataset/310463/taxon/B38Q8 Genus Amoebophrya https://www.checklistbank.org/dataset/310463/taxon/6299Z Species Anisolpidium rosenvingei https://www.checklistbank.org/dataset/310463/taxon/66RMQ Family Chytridiaceae https://www.checklistbank.org/dataset/310463/taxon/88G Order Chytridiales https://www.checklistbank.org/dataset/310463/taxon/Y7 Species Dangeardia mamillata https://www.checklistbank.org/dataset/310463/taxon/6CCLG Species Dinomyces arenysensis https://www.checklistbank.org/dataset/310463/taxon/6D7TN Species Endocoenobium eudorinae https://www.catalogueoflife.org/data/taxon/5BQRJ Species Ericiomyces syringoforeus https://www.checklistbank.org/dataset/310463/taxon/B39GB Genus Euduboscquella https://www.checklistbank.org/dataset/310463/taxon/4FJN Kingdom Fungi https://www.checklistbank.org/dataset/310463/taxon/F Species Halomyces littoreus https://www.checklistbank.org/dataset/310463/taxon/6KZKZ Order Lobulomycetales https://www.checklistbank.org/dataset/310463/taxon/3GT Species Paradinomyces triforaminorum https://www.checklistbank.org/dataset/310463/taxon/CBSSD Genus Parvilucifera https://www.checklistbank.org/dataset/310463/taxon/6JBF Species Parvilucifera catillosa https://www.gbif.org/species/182593152 Species Parvilucifera corolla https://www.marinespecies.org/aphia.php?p=taxdetailsid=1361008 Species Parvilucifera sinerae https://www.marinespecies.org/aphia.php?p=taxdetailsid=707712 Family Parviluciferaceae https://www.marinespecies.org/aphia.php?p=taxdetailsid=1731785 Species Pontisma heterosiphoniae https://www.checklistbank.org/dataset/310463/taxon/6W7S9 Species Pontisma muelleri https://www.checklistbank.org/dataset/310463/taxon/77VS9 Species Pontisma pyropiae https://www.checklistbank.org/dataset/310463/taxon/787RX Species Protrudomyces lateralis https://www.checklistbank.org/dataset/310463/taxon/4N7SG Order Rhizophydiales https://www.checklistbank.org/dataset/310463/taxon/3YH Species Sirolpidium bryopsidis https://www.checklistbank.org/dataset/310463/taxon/4XRB8 Genus Snorkelia https://www.marinespecies.org/aphia.php?p=taxdetailsid=1731854 Genus Thraustochytrium https://www.marinespecies.org/aphia.php?p=taxdetailsid=119095 Species Thraustochytrium kinnei https://www.checklistbank.org/dataset/310463/taxon/56LMR Order Zygophlyctidales https://www.checklistbank.org/dataset/310463/taxon/9YKVR Genus Zygophlyctis https://www.checklistbank.org/dataset/310463/taxon/8BDW Species Zygophlyctis asterionellae https://www.checklistbank.org/dataset/310463/taxon/5DBJX Species Zygophlyctis planktonica https://www.checklistbank.org/dataset/310463/taxon/5DBJZ Species Zygorhizidium affluens https://www.checklistbank.org/dataset/310463/taxon/5DC25 Species Maranthos nigrum https://doi.org/10.3389/fmicb.2021.701196 Species Miracula islandica https://doi.org/10.1080/12298093.2021.1952813 Genus Tuberlatum https://doi.org/10.1016/j.protis.2018.12.003 Species Dinomyces gilberthii https://www.catalogueoflife.org/data/taxon/C9MCR Species Dinovorax pyriformis https://www.marinespecies.org/aphia.php?p=taxdetailsid=1731853 Species Paradinomyces evelyniae https://www.catalogueoflife.org/data/taxon/CBSSC Species Staurastromyces oculus https://www.catalogueoflife.org/data/taxon/4ZLXX Species Zygophlyctis asterionellae https://www.catalogueoflife.org/data/taxon/5DBJX Species Zygorhizidium planktonicum https://www.catalogueoflife.org/data/taxon/5DC2C http://www.w3.org/ns/dcat#keyword https://kos.lifewatch.eu/thesauri/alienspecies/c_45a0f010 http://www.w3.org/ns/dcat#keyword http://vocabs.lter-europe.net/elter_cl/10713 http://www.w3.org/ns/dcat#keyword http://vocabs.lter-europe.net/EnvThes/20588 http://www.w3.org/ns/dcat#keyword http://vocabs.lter-europe.net/elter_cl/10714 http://www.w3.org/ns/dcat#keyword http://vocabs.lter-europe.net/EnvThes/20674 http://www.w3.org/ns/dcat#keyword http://vocabs.lter-europe.net/EnvThes/10100 http://www.w3.org/ns/dcat#keyword http://vocabs.lter-europe.net/EnvThes/20590 http://www.w3.org/ns/dcat#keyword http://vocabs.lter-europe.net/EnvThes/21108 http://www.w3.org/ns/dcat#keyword https://kos.lifewatch.eu/thesauri/alienspecies/c_242 Serena Rasconi Université Savoie Mont Blanc Researcher Serena.Rasconi@gmail.com 0000-0001-6667-8904 Andrea Tarallo National Research Council (CNR), Institute of Research on Terrestrial Ecosystems (IRET) Technologist andrea.tarallo@cnr.it 0000-0002-2749-8588 DOI https://doi.org/10.48372/d20t-xw44 Info and download page on LifeWatch Italy Data Portal https://data.lifewatchitaly.eu/handle/123456789/326353 The data used in this study were sourced from both published works and unpublished observations contributed by ParAqua members. The data collection focused on parasite-host interactions and the presence of parasite species in the environment. The collected data comprise a list of identification of zoosporic parasites of algae collected from natural environments, along with observations of confirmed or putative parasite-host interactions. The identification of the parasitic taxon is based on microscopy observation and/or molecular sequence or inferred by previous literature. Where available, we also recorded additional information, such as the ecosystem type and the geographical context of each observation. For geographic coordinates, the original latitude and longitude were recorded and standardised to decimal coordinates. The coordinates were then manually checked for consistency with the locality reported in the original reference. Additional geographical context information was retrieved where possible. The organism abundance is also reported and retained in its original format, along with details of the methodology used for quantification. The organism quantity was converted into presence/absence data (if the organism quantity is zero, it is marked as “absent”, if greater than zero, it is marked as “present”). The full taxonomy of species—including phylum, class, order, family, and genus—was derived from Van den Wyngaert et al. (2025) and verified for accuracy against internationally recognised taxonomic backbones such as WoRMs, Catalogue of Life and AlgaeBase and manually counterchecked by expert review. The classification of Fungi is aligned with Tedersoo et al. (2018). The original description of the species (i.e. verbatim scientificName) and the coordinates (verbatimCoordinates) are reported in the tables to ensure the accuracy of the information provided. To ensure data interoperability and facilitate reuse, we adopted Darwin Core to standardise terminology and harmonise the collected variables. Serena Rasconi Université Savoie Mont Blanc Researcher Serena.Rasconi@gmail.com 0000-0001-6667-8904 Principal Investigator table_taxa_ParAqua_publish.csv table_taxa_ParAqua_publish.csv 27858 MD5:5da33fc49686c2abf097f1398e76738a 1 column , verbatimIdentification Verbatim Identification Taxonomic identification as recorded in the original source. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/verbatimIdentification scientificName Scientific Name Lowest taxonomic rank determinable without qualifications. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/scientificName acceptedNameUsageID Accepted Name Usage ID Global unique identifier or dataset-specific ID. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasCode http://rs.tdwg.org/dwc/terms/acceptedNameUsageID acceptedNameUsage Accepted Name Usage Full name of the currently valid (zoological) or accepted (botanical) taxon. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/acceptedNameUsage scientificNameAuthorship Scientific Name Authorship Authorship information for the acceptedNameUsage. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/scientificNameAuthorship taxonRank Taxon Rank Taxonomic rank of the most specific name. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/verbatimTaxonRank kingdom Kingdom Scientific name of the kingdom. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/kingdom phylum Phylum Scientific name of the phylum or division. 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Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/specificEpithet Behavioural trait Behavioural trait Observable behavioral characteristic (e.g., confirmed parasitic, putative parasitic). Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#ofCharacteristic https://kos.lifewatch.eu/thesauri/traits/c_cc244e43 Behavioural traitReference Behavioural trait Reference Authorship information for the BehaviouralTrait Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/associatedReferences associatedTaxa Associated Taxa List of identifiers/names of taxa associated with the behavioral trait. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/associatedTaxa 91 table_obs_ParAqua_publish.csv table_obs_ParAqua_publish.csv 1757616 MD5:005606d573844e5803ba5db3b52f6a32 1 column , catalogNumber Catalog Number Unique identifier for the record within the dataset or collection. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/catalogNumber verbatimEventDate Verbatim Event Date Original representation of the date and time of the observation. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/verbatimEventDate eventDate Event Date Date-time or interval during which the observation occurred. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/eventDate decimalLatitude Decimal Latitude Geographic latitude in decimal degrees. 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Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#usesProtocol http://rs.tdwg.org/dwc/terms/measurementRemarks verbatimIdentification Verbatim Identification Taxonomic identification as recorded in the original source. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/verbatimIdentification scientificName Scientific Name Lowest taxonomic rank determinable without qualifications. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/scientificName taxonRank Taxon Rank Taxonomic rank of the most specific name. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/taxonRank kingdom Kingdom Scientific name of the kingdom. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/kingdom phylum Phylum Scientific name of the phylum or division. 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Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/acceptedNameUsage scientificNameAuthorship Scientific Name Authorship Authorship information for the acceptedNameUsage. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/terms/scientificNameAuthorship acceptedNameUsageID Accepted Name Usage ID Global unique identifier or dataset-specific ID. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasCode http://rs.tdwg.org/dwc/terms/acceptedNameUsageID recordedBy Recorded By Person, group, or organization recording the observation. Any Text http://ecoinformatics.org/oboe/oboe.1.2/oboe-core.owl#hasContext http://rs.tdwg.org/dwc/iri/recordedBy 4427