The effect of past experience on the size of shells selected by hermit crabs

Abstract

The relationship between crab size and shell size selected, in a free-choice situation, was tested for crabs maintained under several conditions. Individuals of Calcinus tibicen that were held and presented with an excess of shells for 7 days prior to testing selected smaller shells than control crabs (either those maintained for 7 days with no excess shells available or those experiencing natural field conditions). This shift occurred whether the excess shell type was the same or different from the shell type tested after experience. In a similar set of experiments, individuals of C. laevimanus were held for 31 days and although the trends in shell choice were similar to those for C. tibicen, the differences were not significant.