Unmasking the Killer of Caribbean Sea Urchins.

A scuticociliate, a single-celled organism, has been identified as the cause of the 2022 mass die-off of long-spined sea urchins in the Caribbean and Florida’s east coast. These urchins are crucial for coral reef health, and the discovery raises questions about the ciliate’s presence, growth conditions, and potential impact on other species. The research team used genomic techniques to identify the ciliate in every affected urchin specimen and confirmed it as the disease source by performing infection experiments at the USF College of Marine Science.