On the Pacific coast of Costa Rica, a major predator in the community of animals living on sandy beaches is a snail, a species of Olive Shell (Agaronia propatula). This snail moves up and down the beach by "surfing," extending its foot so that it is carried along in the wave swash. It is a voracious hunter, and its main prey is a smaller species of Olive Shell. In its wave-washed environment it has to act quickly. It pounces on its prey, "swallows" it into a pouch in its foot, then burrows into the sand where it can eat it undisturbed. A recent study I conducted with colleagues from Indiana University-Purdue University Fort Wayne and Goldring-Gund Marine Biology Station in Costa Rica has revealed that these predatory snails are quite indiscriminate in their attacking behavior. They will tackle almost any moving objects, including paperclips, cotton swabs, and pencil-sized pieces of plastic, attempting to engulf them. Not even the toes of unwary bathers are safe!
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A version of this post originally appeared on OUPblog.
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