Mass mortality of diadematoid sea urchins in the Red Sea and Western Indian Ocean

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Academic Press, 2020: 397-418 Crossref Scopus (10) Google Scholar including first evidence of mortalities in the genus Echinothrix Peters, 1853. Mortalities initiated in the Gulf of Aqaba on December 2022 and span the Red Sea, the Gulf of Oman, and the Western Indian Ocean (Réunion Island), with population declines reaching 100% at some sites. Infected individuals are characterized by spine loss and tissue necrosis, resulting in exposed skeletons (i.e., tests) and mortality. Molecular diagnostics of the 18S rRNA gene confirm the presence of a waterborne scuticociliate protozoan most closely related to Philaster apodigitiformis in infected specimens—identical to the pathogen found in the 2022 Caribbean mass mortality of Diadema antillarum. 13 Levitan D.R. Best R.M. Edmunds P.J. Sea urchin mass mortalities 40 y apart further threaten Caribbean coral reefs. Proc. Natl. Acad. Sci. 2023; 120e2218901120https://doi.org/10.1073/pnas.2218901120 Crossref Scopus (8) Google Scholar ,15 Hylkema A. 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Science. 2007; 318: 1737-1742https://doi.org/10.1126/science.1152509 Crossref PubMed Scopus (4222) Google Scholar We issue a warning regarding the further expansion of mortalities and call for immediate monitoring and conservation efforts for these key ecological species.