Terrestrial molluscs are usually an important component of the invertebrate fauna in the native habitats of islands. With a total of 111 species the molluscs are dominated by the order Stylommatophora (Gastropoda) with 93 species.
With the exception of Corvo the other Azorean islands show species richness above 40 species and endemism richness equal or above ten. It is worth noting that São Miguel has the most diversified malacofauna with 76 species, of which 22% are endemic to the Azores. In six of the nine islands the endemism represents over 25% of their malacofauna, in São Jorge it even reaches 33,3%. In the remaining islands the rate of endemism remains between 17% and 24%.Only four islands have exclusive endemic species; Santa Maria tops them all with about 70%. In S�o Miguel and Terceira over 20% of the endemics are exclusive to the island, whereas in Faial less than 10% are exclusive.
Due to its high percentage of endemism the Azorean malacofauna is not only a very important scientific heritage and a fascinating research object, but it also constitutes an invaluable indicator of conservation strategies, and its thorough study should be considered a priority.
Containing the 111 terrestrial Mollusca species and subspecies hitherto recorded from Azores with 50 species illustrated, totalling 66 photos (Updated 22nd January 2012).