Investigations on the malacofauna of the Calafuria area (Livorno, Italy)

The present work is aimed at providing a general outline of the marine shelled molluscan fauna of the area of Calafuria (Livorno, Italy), established in 2020 as a Site of Community Importance (SCI) under the EU Habitat Directive, which was studied through samples obtained by scuba-diving or free-diving. Aside from a study of the death assemblage based on samples collected between 2018 and 2022, historical collections were also examined, with the final checklist including 695 species overall. Among the species identified in this study, 23 are not reported for sector 1 of the latest update of the Italian checklist; another five species possibly representing first records for sector 1 have been identified only tentatively. Lastly, some taxa were identified only to the genus level, as they belong to groups in which identification based on shell features only is not reliable; this group might include undescribed species belonging to the genera Curveulima, Vitreolina, Ammonicera, Ebala, Haminoea, Laona, and Turbonilla. Replicate samples obtained in 2018–2022 allowed us to obtain accumulation curves and variability estimates for different depth ranges. Moreover, we calculated Shannon-Wiener’s and Simpson’s diversity indices, which show values typical of environments characterised by high diversity and evenness, and the absence of dominant species.