This text contains the papers of a meeting on American isopods, the only crustacean group with representatives in all terrestrial ecosystems ranging from the sea shore to the desert. Due to such adaptibility, this group can be seen as a model for the successful transition on land. The text deals with two main subjects: the effects of stressful conditions on the individual animal as reflected by its survival or by the disruption of its normal reproductive pattern; and the distribution of the isopods and their selection of microhabitat.