Visualization System for Burrowing Organisms in Granular Substrates

Abstract

This fluid dynamics video demonstrates the capabilities of an experimental setup to visualize organisms burrowing in granular substrates. The setup consists of a tank filled with 1mm soda-lime glass beads, backlit by halogen lights. The walls can be moved such that the space bound by them can expand or contract to fit various organisms. A recirculation system oxygenates and cools the salt water that flows through the substrate. The video shows the burrowing behavior of a razor clam (Ensis directus) and a quahog (Mercenaria mercenaria). Both animals inflate their foot with blood, making the foot a terminal anchor against which they pull their shell downwards. Deformation of the granular substrate can be seen around the animals as they advance downwards.