Abstract
BACKGROUND: The Hellenic Seas are influenced by on-going environmental changes and the introduction of alien species, which are expected to have an impact on their biodiversity. This study contributes to the knowledge of the Hellenic marine gastropod biodiversity, expanding data over the entire Greek territory, during the period from October 2008 to March 2017. RESULTS: This work presents 45 species of gastropods not previously reported from Greece or reported only once, belonging to 19 families. From those species, one (Horologica sp.) is, most probably, an undescribed species, 17 are new for the Eastern Mediterranean Sea and 40 are new for the Hellenic fauna. Main taxonomic characteristics and ecological information such as habitat, distribution and origin, are given and discussed. CONCLUSIONS: By this report, the Hellenic gastropod biodiversity is enriched by 40 new records, out of which, 17 are new for the Eastern Mediterranean Sea, 4 are Lessepsian migrants previously reported for the Mediterranean Sea and 1 is probably a new species.