Sponge Fauna of the Apulian Marine Caves (Southern Italy): Current State of Knowledge

Submerged and semi-submerged marine caves are considered a European habitat of Community Interest as they preserve one of the most important biodiversity heritages in the Mediterranean and serve as refugia for endemic and/or “relict” species. Among sessile benthic taxa, caves represent significant reservoirs of sponge species richness and are well representative of the entire poriferan Mediterranean fauna. In order to assess the current knowledge of sponge species in marine caves along the Apulian coast, this study gathered data from the available literature (national and international scientific publications and grey literature) with original data, surveying 26 marine caves in the area. A total of 145 Porifera species were reported in marine caves on the Apulian coast, including 117 in the Tremiti archipelago, 33 along the Adriatic coast of Bari and 73 along the Salento Peninsula. Original data includes new records for nine species in the Corvine cave, two in the Murene cave and one in the Zinzulusa cave. Our results suggest that marine cave communities along the Apulian coast are not uniformly surveyed, being the caves of the Tremiti Islands and those of the Salento Peninsula among the best studied, while large stretches of the regional coast, although particularly rich in marine caves, are poorly investigated for their sponge fauna.