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Issue: Vol. 5862 No. 3: 6 Aug. 2026
Type: Article
Published: 2026-08-06
DOI: 10.11646/zootaxa.5862.3.4
Page range: 472-486
Abstract views: 259
PDF downloaded: 27

Uncovering a poorly known Mediterranean species thanks to underwater photography and video: Ophiacantha setosa (Echinodermata: Ophiuroidea)

Centre d’Écologie et des Sciences de la Conservation (CESCO); Muséum National d’Histoire Naturelle; Centre National de la Recherche Scientifique; Sorbonne Université; 61 rue Buffon; 75005 Paris; France
NaturDive; 1 avenue des Broussailles; 06400 Cannes; France
EDF Hydro Méditerranée; Les carrés du Golf; 1165 Avenue JRG Gautier de la Lauziere; 13290 Aix-En-Provence; France
Andromède Océanologie; 7 place Cassan - Carnon plage; 34130 Mauguio; France
Andromède Océanologie; 7 place Cassan - Carnon plage; 34130 Mauguio; France
Swedish Museum of Natural History; Department of Zoology; Frescativägen 40; 10405 Stockholm; Sweden
Echinodermata Octocorallia mesophotic ecosystems brittle stars epizoic citizen science host selectivity Ophiuroidea Mediterranean sea biodiversity monitoring

Abstract

The brittle star species Ophiacantha setosa (Bruzelius, 1805) was historically documented only from dredged material and morphological taxonomic accounts, with little information on its live appearance, ecology, or behaviour, and had never been illustrated in situ. Here we combine a morphological diagnosis with new underwater observations obtained through scientific and technical diving, high-resolution photography, and citizen science contributions to provide the first comprehensive account of O. setosa in life. The species was observed between 25 and 130 m depth at several Mediterranean localities, consistently living as an epibiont on octocorals. Host use varied with depth, shifting from shallow coralligenous gorgonians (Leptogorgia sarmentosa, Paramuricea clavata, Eunicella cavolini) to deeper mesophotic species (Callogorgia verticillata) and soft corals (Alcyonium palmatum). Despite their abundance, several potential hosts, including Corallium rubrum, were never colonized, possibly suggesting active host selectivity rather than random association. Our observations reveal previously unknown aspects of the species’ morphology, colouration, depth distribution, and ecological preferences, and highlight the value of underwater imagery and citizen science for documenting overlooked marine invertebrates. This study fills a long-standing knowledge gap for O. setosa and illustrates how modern observational approaches can help rediscover and characterize “ghost species” in marine biodiversity databases.

References

  1. Abildgaard, P.C. In: Müller, O.F. (1789) Zoologia Danica seu animalium Daniae et Norvegiae rariorum ac minus notorum descriptiones et historia. Vol. 3. N. Möller/N. Christensen, Hauniae, 71 pp. [in Latin]
  2. Andromède Océanologie (2022) Expédition scientifique Gombessa 6: Le mystère des anneaux coralligènes. Rapport final, 338 pp. [in French]. [https://parc-marin-cap-corse-agriate.fr/contact-0]
  3. Andromède Océanologie (2023) Expédition Gombessa 6+—Missions 2022/2023. Poursuite des activités de R&D sur les habitats profonds dans le Parc Naturel Marin du Cap Corse et de l’Agriate. Rapport final, 365 pp. [in French]. [https://parc-marin-cap-corse-agriate.fr/contact-0]
  4. Aristotle (-343) Histoire des animaux. Garnier Flammarion, Paris, 672 pp. [in French, original language is ancient Greek]
  5. Blainville, H.-M.D. de (1834) Manuel d’actinologie ou de zoophytologie. Levrault, Paris, 688 pp. [in French]
  6. Bourjon, P., Ducarme, F., Quod, J. & Sweet, M. (2018) Involving recreational snorkelers in inventory improvement or creation: a case study in the Indian Ocean. Cahiers de Biologie Marine, 59, 451–460. https://doi.org/10.21411/CBM.A.B05FC714
  7. Bruzelius, N. (1805) Dissertatio sistens species cognitas asteriarum, quam. sub praesidio A.J. Retzii. exhibet N. Bruzelius. Lundae, 37 pp. [in Latin]
  8. Chammem, H., Ben Souissi, J. & Pérez-Ruzafa, A. (2019) Checklist with first records for the Echinoderms of northern Tunisia (central Mediterranean Sea). Scientia Marina, 83 (3), 277–288. https://doi.org/10.3989/scimar.04899.19A
  9. Cherbonnier, G. (1962) Ophiurides. In: Expédition océanographique belge dans les eaux côtières africaines de l’Atlantique sud (1948–1949). Vol. 3 (8). Institut Royal des Sciences de Belgique, Bruxelles, 60 pp. [in French]
  10. Chimienti, G. (2020) Vulnerable Forests of the Pink Sea Fan Eunicella verrucosa in the Mediterranean Sea. Diversity, 12, 176. https://doi.org/10.3390/d12050176
  11. Christodoulou, M., O’Hara, T.D., Hugall, A.F. & Arbizu, P.M. (2019) Dark Ophiuroid Biodiversity in a Prospective Abyssal Mine Field. Current Biology, 29 (22), 3909–3912.e3. https://doi.org/10.1016/j.cub.2019.09.012
  12. Deter, J., Holon, F. & Boissery, P. (2011) Mise en place et développement du RECOR, un réseau de surveillance des peuplements du coralligène en mer Méditerranée. Analyse de données de la région Corse 2011. Contrat oeil d’Andromède / Agence de l’eau (2011–2014), 153 pp. [in French] [https://medtrix.fr/wp-content/uploads/2019/09/RECOR-Surveillance-biologique-2011.pdf]
  13. Ehrenberg, C.G. (1834) Beiträge zur physiologischen Kenntniss der Corallenthiere im allgemeinen, und besonders des rothen Meeres, nebst einem Versuche zur physiologischen Systematik derselben. Abhandlungen der Königlichen Akademie der Wissenschaften, 1, 225–380. [in German]
  14. Esper, E.J.C. (1788–1830) Die Pflanzenthiere in Abbildungen nach der Natur mit Farben erleuchtet, nebst Beschreibungen. Zweyter Theil. Raspe, Nürnberg, 303 pp. [in German]
  15. Goharimanesh, M., Ghassemzadeh, F., De Kegel, B., Van Hoorebeke, L., Stöhr, S., Mirshamsi, O. & Adriaens, D. (2022) The evolutionary relationship between arm vertebrae shape and ecological lifestyle in brittle stars (Echinodermata: Ophiuroidea). Journal of Anatomy, 240, 1034–1047. https://doi.org/10.1111/joa.13617
  16. Gray, J.E. (1840) A synopsis of the genera and species of the class Hypostoma (Asterias, Linnaeus). Annals and Magazine of Natural History, XXII, 6, 175–184. https://doi.org/10.1080/03745484009443282
  17. Gray, J.E. (1857) Description of a new genus of Gorgoniadae. Proceedings of the Zoological Society of London, 128–129.
  18. Grube, A.E. (1840) Actinien, Echinodermen und Würmer des Adriatischen- und Mittelmeers nach eigenen Sammlungen beschrieben. J.H. Bon, Königsberg, 92 pp. [in German] https://doi.org/10.5962/bhl.title.23025
  19. Hickson, S.J. (1904) The Alcyonaria of the Cape of Good Hope, Part II. Marine Investigations in South Africa, 3, 211–239. https://doi.org/10.5962/p.366544
  20. Johnson, J.Y. (1863) Description of a new species of flexible coral belonging to the genus Juncella, obtained at Madeira. Proceedings of the Zoological Society of London, 505–506.
  21. Koch, G. von (1887) Die Gorgoniden des Golfes von Neapel und der angrenzenden Meeresabschnitte. Fauna und Flora des Golfes von Neapel, 15, 1–99. [in German] https://doi.org/10.5962/bhl.title.13749
  22. Koehler, R. (1898) Résultats des campagnes scientifiques accomplies sur son yacht par Albert Ier, prince souverain de Monaco - échinides et ophiurides. 12, 1–78. [in French]
  23. Koehler, R. (1921) Faune de France – Echinodermes. 210 pp. [in French]
  24. Lamarck, J.-B. (1816) Histoire naturelle des animaux sans vertèbres : présentant les caractères généraux et particuliers de ces animaux, tome II, « Radiaires ». Verdière, Paris, 568 pp. [in French]
  25. Lamarck, J.-B. (1840) Histoire naturelle des animaux sans vertèbres : présentant les caractères généraux et particuliers de ces animaux, deuxième édition revue et augmentée, tome III, « Radiaires ». Baillière, Paris, 450 pp. [in French]
  26. Lim, G.S., Balke, M. & Meier, R. (2012) Determining Species Boundaries in a World Full of Rarity: Singletons, Species Delimitation Methods. Systematic Biology, 61 (1), 165–169. https://doi.org/10.1093/sysbio/syr030
  27. Linck, J.H. (1733) De Stellis marinis liber singularis, tabularum aenearum figuras... et autoris observationes disposuit... Accedunt Edw. Luidii, de Réaumur et Dav. Kade hujus argumenti opuscula. J. Schusterum, 107 pp. [in Latin] https://doi.org/10.5962/bhl.title.120095
  28. Linnaeus, C. (1758) Systema Naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Impensis Direct. Laurentii Salvii, Stockholm, 1(10) [iii], 824 pp. [in Latin]
  29. Ljungman, A. (1867) Ophiuroidea viventia huc usque cognita enumerat. Öfversigt af Kgl. Vetenskaps-Akademiens Förhandlingar, 23 (9), 303–336. [in Latin]
  30. Lyman, T. (1882) Report on the Ophiuroidea dredged by H.M.S. Challenger during the Years 1873–1876. Report on the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873–76. Zoology, 5 (part 14), 1–387. https://doi.org/10.5962/bhl.title.12507
  31. Metaxas, A. & Giffin, B. (2004) Dense beds of the ophiuroid Ophiacantha abyssicola on the continental slope off Nova Scotia, Canada. Deep Sea Research Part I: Oceanographic Research Papers, 51 (10), 1307–1317. https://doi.org/10.1016/j.dsr.2004.06.001
  32. Morgan, R. & Jangoux, M. (2004) Juvenile–adult relationship in the gregarious ophiuroid Ophiothrix fragilis (Echinodermata): a behavioral and morphological study. Marine Biology, 145 (2), 265–276. https://doi.org/10.1007/s00227-004-1327-5
  33. Müller, J.-P. & Troschel, F.H. (1842) System der Asteriden. Friedrich Vieweg und Sohn, Braunschweig, 134 pp. [in German]
  34. O’Hara, T.D., Hugall, A.F., Thuy, B., Stöhr, S. & Martynov, A.V. (2017) Restructuring higher taxonomy using broad-scale phylogenomics: The living Ophiuroidea. Molecular Phylogenetics and Evolution, 107, 415–430. https://doi.org/10.1016/j.ympev.2016.12.006
  35. Pallas, P.S. (1766) Elenchus zoophytorum sistens generum adumbrationes generaliores et specierum cognitarum succinctas descriptiones, cum selectis auctorum synonymis. Franciscum Varrentrapp, Hagae, 451 pp. [in Latin] https://doi.org/10.5962/bhl.title.6595
  36. Peyghan, S., Doustshenas, B., Nabavi, M.B., Rounagh, M.T., Larki, A.A. & Stöhr, S. (2018) New records of the brittle stars Ophiothela venusta and Ophiactis modesta (Echinodermata: Ophiuroidea) from the northern Persian Gulf, with morphological details. Zootaxa, 4527 (3), 425–435. https://doi.org/10.11646/zootaxa.4527.3.11
  37. Rineau, Y., Crémieu, A. & Ballesta, L. (2024) Cap Corse - Le mystère des anneaux. Available from: https://www.youtube.com/watch?v=KALtjclocrI
  38. Risso, A. (1826–1827) Histoire Naturelle des Principales Productions de l’Europe Méridionale et Particulièrement de Celles des Environs de Nice et des Alpes Maritimes. Tome V. F.-G. Levrault, Paris, 403 pp. [in French]
  39. Sars, G.O. (1872) Nye Echinodermer fra den norske kyst. Videnskabelige Selskabets Forhandlinger, 1871, 1–31. [in Danish]
  40. Sars, M. (1859) Bidrag til Kundskaben om Middelhavets Littoral-Fauna, Reisebemærkninger fra Italien (2den Afhandling). Nyt Magazin for Naturvidenskaberne, 10 (1), 57–155. [in bokmål Norwegian]
  41. Savigny, J.C. (1816) Mémoires sur les animaux sans vertèbres. Paris, 2, 239 pp. https://doi.org/10.5962/bhl.title.9154
  42. Stöhr, S. (2012) Ophiuroid (Echinodermata) systematics – where do we come from, where do we stand and where should we go? In: Kroh, A. & Reich, M. (Eds.), Echinoderm Research 2010: Proceedings of the Seventh European Conference on Echinoderms, Göttingen, Germany, 2–9 October 2010. Vol. 7. Zoosymposia, pp. 147–161. https://doi.org/10.11646/zoosymposia.7.1.14
  43. Stöhr, S. (2025) Two new species of brittle stars (Echinodermata: Ophiuroidea), living epizoic on a stalked crinoid. European Journal of Taxonomy, 1022, 176–201. https://doi.org/10.5852/ejt.2025.1022.3087
  44. Stöhr, S., O’Hara, T.D. & Thuy, B. (2012) Global diversity of brittle stars (Echinodermata: Ophiuroidea). PLoS ONE, 7 (3), 1–14. https://doi.org/10.1371/journal.pone.0031940
  45. Stöhr, S., O’Hara, T.D. & Thuy, B. (2026) World Ophiuroidea Database. Available from: http://www.marinespecies.org/ophiuroidea (accessed 3 February 2026)
  46. Stöhr, S., Weber, A.A.-T., Boissin, E. & Chenuil, A. (2020) Resolving the Ophioderma longicauda (Echinodermata: Ophiuroidea) cryptic species complex: five sisters, three of them new. European Journal of Taxonomy, 600. https://doi.org/10.5852/ejt.2020.600
  47. Thuy, B. & Stöhr, S. (2011) Lateral arm plate morphology in brittle stars (Echinodermata: Ophiuroidea): new perspectives for ophiuroid micropalaeontology and classification. Zootaxa, 3013 (1), 1–47. https://doi.org/10.11646/zootaxa.3013.1.1
  48. Toma, M., Bavestrello, G., Enrichetti, F., Costa, A., Angiolillo, M., Cau, A., Andaloro, F., Canese, S., Greco, S. & Bo, M. (2024) Mesophotic and Bathyal Echinoderms of the Italian Seas. Diversity, 16 (12), 753. https://doi.org/10.3390/d16120753
  49. Tortonese, E. (1965) Fauna d’Italia. Vol. 6. Echinodermata. Edizioni Calderini, Bologna, 422 pp. [in Italian]

How to Cite

Ducarme, F., Jéglot, S., Réty, C., Deter, J., Ballesta, L. & Stöhr, S. (2026) Uncovering a poorly known Mediterranean species thanks to underwater photography and video: Ophiacantha setosa (Echinodermata: Ophiuroidea). Zootaxa, 5862 (3), 472–486. https://doi.org/10.11646/zootaxa.5862.3.4