Behavior and Physical Factors Causing Migration and Aggregation of the Sand Crab Emerita Analoga (Stimpson)

Migration and distribution of Emerita on sand beaches can be explained in terms of water flow and a simple behavioral response. Wash zones of sand beaches are bounded burrow out of fluid sand and so are kept within the boundaries of the wave wash. As the position of a wash zone is shifted with the tide, Emerita are carried in it to new locations on the beach. Lateral flow within the wave wash distributes Emerita into clumps along the shore.