Synagoga mira Norman, 1888 is a poorly known ascothoracidan that has never been reported since its original description in 1888, which was based on a few specimens recovered from colonies of the black coral Parantipathes larix (Esper, 1788) collected in the Gulf of Naples (Mediterranean Sea). A series of Remotely Operated Vehicle (ROV) campaigns conducted between 2006 and 2022 along the Italian coast (western Mediterranean Sea) identified numerous P. larix forests, allowing the investigation of the presence of S. mira on a broad geographical and bathymetric scale and the collection of twelve specimens. The first pictures of both in situ and collected specimens are reported here. The sexes seem separated and slightly skewed towards females. Synagoga mira, specialised in grazing the living tissue of P. larix, is confirmed overall as a rare species (19.2% of the sites with black coral forests between 109 and 251 m). The highest frequency of records (12 sites) and abundance of individuals (588) were confined to the Pontine Archipelago, a hot spot of occurrence of this black coral. Infestation occurred in up to 68.8% of the host colonies, with up to 46 individuals per infested colony. The health status of the coral colonies seems not to influence the infestation from S. mira. This study provides the first ecological data on an enigmatic and poorly known crustacean, also representing the first information for mesophotic ascothoracidans.
