Snail-pollination in Volvulopsis nummularium

Abstract

Pollination is a crucial ecological process that aids sexual reproduction in flowering plants. Although a variety of animals are known to bring about pollen transfer, pollination by snails (malacophily) has remained a rare and obscure phenomenon. Here we conclusively demonstrate the incidence of malacophily in Volvulopsis nummularium (family Convolvulaceae, commonly known as the morning glory family), a prostrate rainy-season weed, which is also visited by honey bees. Flowers open in the morning and last only for half a day. Apis cerana indica and Graceful Awlsnail (Lamellaxis gracile) are the pollinators. Snails are exclusive pollinators on rainy days, when bees are not active. Contrary to the belief that snails are destructive, we found that they do not affect the natural fecundity of V. nummularium. Manualpollinations indicated that the plants were facultative autogamous. Pollination in V. nummularium by snails and honey bees represents an interesting guild, which is of adaptive significance in achieving high reproductive success without resorting to obligate selfing.