The Picture of Dorian Gray: shell corrosion allows freshwater and brackish-water gastropods to masquerade as empty shells

Abstract

ABSTRACTThe shells of some freshwater and brackish-water gastropods, including species of Pleuroceridae, Vivipalidae, and Neritidae, show considerable deterioration while their inhabitants are still alive and reproductively active, giving them the appearance of dead or empty shells. Although the worn-out appearance of these shells may be an inevitable outcome of their tendency to dissolve in calcium-poor water, it is possible that the gastropods adjust their investment in shell calcification to allow for moderate shell corrosion. The habitats where gastropods live retain many old, empty shells, and, by mimicking these disused shelters in appearance and texture, gastropods with corroded shells may avoid detection by predators using visual and tactile cues to locate prey. A similar behaviour, whereby animals use niche construction by conspecific antecedents to masquerade as old deserted dwellings, may also be found in other animal groups, such as leaf-rolling caterpillars, leaf beetles and land snails on limestone habitats.