Acid secretion in gastropods

Gastropoda is probably the best-known taxon which uses acid glands as an antifouling strategy
and as defence against putative predators. Here, defensive acid-secreting cell types in two taxa
of Caeonogastropoda, Cypraeidae and Ovulidae, were investigated. This study confirms the
presence of acid epithelial glands in several members of the Cypraeidae, with the glands of
the Cypraeidae species Naria nebrites and Mauritia mauritiana being newly described here.
We also present results for the first time on a member of the family Ovulidae, Simnia spelta.
All investigated species exhibited an outer epidermis with glandular acid cells of columnar
shape with large clear, colourless vacuoles, thus resembling the previously described species
of these taxa. None of the investigated cypraeid and ovulid species studied here exhibited
subepidermal acid glands in the mantle, which are typical for the Velutinoidea. The
phylogenetic value of these findings is discussed in relation to a recently published
phylogeny on Caenogastropoda comprising all families of Cypraeoidea and Velutinoidea.