Biology and conservation status of the endemic Maltese top-shell Gibbula nivosa (A. Adams, 1851) (Trochidae)

Abstract

The Maltese top-shell, Gibbula nivosa, was first described by A. Adams in 1851, who, however, did not state from where the specimens he described had originated. Comparisons of Adams‘ type material with shells collected from around the central Mediterranean island of Malta established that G. nivosa occurs at this locality (Ghisotti, 1976), while it has never been recorded from anywhere else in the Mediterranean, despite extensive searches by shell collectors (Schembri, 1985). Such a situation is practically unique amongst marine molluscs within the whole Mediterranean region (Palazzi, 1978) and G. nivosa is now firmly established as a Maltese endemic (Ghisotti, 1976) and is protected under local and European Union legislation as well as by international conventions (the Bern Convention and Barcelona Convention).