 On the coast of the Caraguatatuba, Brazil, a study of shell use in the diogenid hermit crab species "Isocheles sawayai" was carried out.This study revealed that 11.5% of the population of these hermit crabs were using shells of "Semicassis granulata".The occupation of shell type was reported as not being random, but was instead described as being influenced by the weight, size, shape and internal volume of the shell, the occurrence of epibionts such as bryozoans on the shell, and the degree of resistance the shell offered to predation and desiccation.