Introduced species in Mediterranean marine caves: an increasing but neglected threat

Marine caves are protected habitats with high biodiversity and low ecological resilience, vulnerable to multiple pressures including biological invasions. Therefore, comprehensive lists of alien species in sea assessments their impacts urgently needed. This study aimed provide an updated validated list introduced marine the Mediterranean Sea based on latest available checklist (2014). The number (December 2022 status) has doubled last eight years. includes 126 (107 alien, 15 cryptogenic, two crypto-expanding, questionable) belonging 12 phyla. highest was evidenced eastern (105), specifically Levantine (99) Aegean (34) ecoregions. Most originated from Indo-Pacific. entered through Suez Canal, followed by transferred via vessels. were found at entrance semi-dark zone (60 52 species, respectively), only 19 being reported dark zone. Approximately 28% have a impact ecosystems, nine ten worst invasive Sea. Despite lack data cave biodiversity, given richness recently population explosions some fish Mediterranean, our results highlight need for continuous inventorying monitoring.