Brayan Vilanova-Cuevas
Ashley Altera
Kaileigh Cornfield
Ceri Evans
James S. Evans
Maria Hopson-Fernandes
Christina A. Kellogg
Elayne Looker
Oliver Taylor
Ian Hewson
Mya Breitbart
Isabella T. Ritchie
2024
<p class="chapter-para">Mass mortality of the dominant coral reef herbivore<span> </span><i>Diadema antillarum</i><span> </span>in the Caribbean in the early 1980s contributed to a persistent phase shift from coral- to algal-dominated reefs. In 2022, a scuticociliate most closely related to<span> </span><i>Philaster apodigitiformis</i><span> </span>caused further mass mortality of<span> </span><i>D. antillarum</i><span> </span>across the Caribbean, leading to >95% mortality at affected sites. Mortality was also reported in the related species<span> </span><i>Diadema setosum</i><span> </span>in the Mediterranean in 2022, though the causative agent of the Mediterranean outbreak has not yet been determined. In April 2023, mass mortality of<span> </span><i>Diadema setosum</i><span> </span>occurred along the Sultanate of Oman's coastline. Urchins displayed signs compatible with scuticociliatosis including abnormal behavior, drooping and loss of spines, followed by tissue necrosis and death. Here we report the detection of an 18S rRNA gene sequence in abnormal urchins from Muscat, Oman, that is identical to the<span> </span><i>Philaster</i><span> </span>strain responsible for<span> </span><i>D. antillarum</i><span> </span>mass mortality in the Caribbean. We also show that scuticociliatosis signs can be elicited in<span> </span><i>Diadema setosum</i><span> </span>by experimental challenge with the cultivated<span> </span><i>Philaster</i><span> </span>strain associated with Caribbean scuticociliatosis. These results demonstrate the<span> </span><i>Philaster</i><span> </span>sp. associated with<span> </span><i>D. antillarum</i><span> </span>mass mortality has rapidly spread to geographically distant coral reefs, compelling global-scale awareness and monitoring for this devastating condition through field surveys, microscopy, and molecular microbiological approaches, and prompting investigation of long-range transmission mechanisms.</p>
application/pdf
10.1093/ismejo/wrae024
en
Oxford University Press
Transglobal spread of an ecologically relevant sea urchin parasite
article