Back from presumed local extinction: the case of Sargassum hornschuchii C. Agardh (Fucales: Heterokontophyta) in the Spanish Mediterranean

This dataset contains the digitized treatments in Plazi based on the original journal article Ballesteros, Enric, De Caralt, Sònia, Cebrian, Emma (2025): Back from presumed local extinction: the case of Sargassum hornschuchii C. Agardh (Fucales: Heterokontophyta) in the Spanish Mediterranean. Cryptogamie, Algologie 46 (6): 81-88, DOI: 10.5252/cryptogamie-algologie2025v46a6, URL: sciencepress.mnhn.fr/sites/default/files/articles/pdf/algologie2025v46a6.pdf ABSTRACT We report on a new record of Sargassum hornschuchii C.Agardh in the Spanish Mediterranean after having no reports for more than a century.

Sargassum hornschuchii was found in a deep-water rocky bottom offshore Menorca together with the kelp Laminaria rodriguezii Bornet and the rockweed Ericaria zosteroides (C.Agardh) Molinari & Guiry. We make an accurate morphological description and provide pictures of the specimens collected. This new record puts into question the assignment of the IUCN “extinct” category for deep-water rare macroalgae as they can go unnoticed for a long time.