Tower construction by the manicure crab Cleistostoma dilatatum during dry periods on an intertidal mudflat

Abstract

Animals living on upper intertidal mudflats experience habitat desiccation during neap tides when water does not flood the habitat. Individuals of the manicure crab Cleistostoma dilatatum construct cone-shaped towers at the entrance of their burrows, in which they remain during neap tides. These towers are the tallest known structures compared to body size built by crabs living on intertidal flats. The frequency of tower construction followed semilunar tidal cycles with most building done prior to neap tides when few crabs were active on the mudflat surface. Bigger crabs tended to make taller and wider towers with a wider pinhole on the top. These towers may regulate the microclimate in burrows. © 2011 Japan Ethological Society and Springer.