An anatomical study of the native New Zealand land snail Wainuia urnula (Gastropoda Rhytididae), with emphasis on the digestive system

Abstract

Wainuia urnula is a small, rhytidid snail, endemic to the Wellington region. It lives among free draining litter of the tree ferns wheki (Dicksonia squarrosa) and ponga (Cyathea dealbata). It is a carnivorous snail, feeding on amphipods. It captures its prey by rapidly elongating the radula, in an operation that takes considerably less than one second. The buccal mass was examined to determine any adaptations for prey capture. It was found to contain a number of features common to other carnivorous snails, but has an unusual skeletal system, in the form of a muscular-hydrostat The stomach contents were also examined. These were found to consist mainly of amphipod remains, but a number of other food items were also present.