{
  "abstract": "Coral reefs are among the most biodiverse ecosystems on Earth and rely on endosymbiosis with Symbiodiniaceae, a diverse family of dinoflagellates essential for coral nutrition and which also play an important role in thermal tolerance. Despite their ecological importance, resolving species boundaries within Symbiodiniaceae remains challenging, partly due to limited phylogenetic signal in commonly used genetic markers and the absence of broadly accepted criteria for species delimitation. Refining taxonomic resolution is therefore critical for understanding symbiont diversity, distributions, and evolutionary relationships. In this study, we delimit two closely related Cladocopium species using a meta‐haplotype framework applied to two hypervariable loci—the ITS2 region and the psbA non‐coding region (psbA ncr ). Slowly evolving markers failed to differentiate Cladocopium proximale (SCF049; described here) from its sister species C. proliferum . In contrast, consistent genetic differences between the two taxa were detected across both hypervariable regions. Together with morphological differences, these results support the recognition of C. proximale and C. proliferum as distinct species. Our results highlight the value of combining multiple hypervariable markers to improve taxonomic accuracy in Symbiodiniaceae, providing a stronger basis for understanding how symbiont diversity and ecological differentiation may influence coral resilience and responses to environmental change. More broadly, closely related Symbiodiniaceae such as these provide important systems for examining speciation processes, including potential ecological differentiation and reproductive compatibility.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Earth and Environmental Sciences (DISAT) University of Milano—Bicocca Milano Italy",
    "Australian Institute of Marine Science Townsville Queensland Australia",
    "School of BioSciences The University of Melbourne Parkville Victoria Australia",
    "MaRHE Center (Marine Research and High Education Centre) Magoodhoo Island Faafu Atoll Maldives",
    "School of Biological Sciences Victoria University of Wellington Wellington New Zealand"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Giorgio Terzi",
      "orcid": "0009-0009-2686-0117"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Madeleine J. H. van Oppen"
    },
    {
      "affs": [
        0,
        3
      ],
      "name": "Davide Seveso"
    },
    {
      "affs": [
        1,
        4
      ],
      "name": "Matthew R. Nitschke"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2cbzs8wfzg5b5.bib",
  "cited_by": 0,
  "doi": "10.1002/ece3.74569",
  "fulltext_url": null,
  "id": "2cbzs8wfzg5b5",
  "issns": [
    "2045-7758",
    "2045-7758"
  ],
  "landing_url": "https://onlinelibrary.wiley.com/doi/10.1002/ece3.74569",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [],
  "openalex": null,
  "pdf_url": "https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.74569",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-05",
  "publisher": "Wiley",
  "ris": "https://research.draconitic.com/paper/2cbzs8wfzg5b5.ris",
  "sources": [
    {
      "first_seen": "2026-11-06T00:21:17Z",
      "native_id": "10.1002/ece3.74569",
      "source": "crossref",
      "url": "https://onlinelibrary.wiley.com/doi/10.1002/ece3.74569"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "issn:2045-7758",
      "subfield": "ecology"
    }
  ],
  "title": "Formal Description of Cladocopium proximale sp. nov., a Coral Photosymbiont From the C1 Radiation",
  "title_text": "Formal Description of Cladocopium proximale sp. nov., a Coral Photosymbiont From the C1 Radiation",
  "type": "peer-reviewed",
  "updated_at": "2026-11-07T00:21:15Z",
  "url": "https://research.draconitic.com/paper/2cbzs8wfzg5b5",
  "venue": "Ecology and Evolution",
  "versions": []
}