A selection of papers presented at the 13th International Conference of the International Bryozoology Association held in ConcepciA3n Chile in January 2004 and hosted by the Universidad de ConcepciA3n and Universidad CatA3lica de la SantA-sima ConcepciA3n. The topics presented in this volume reflect the diversity of studies on bryozoa with authors from 18 countries. They include investigations in seven thematic areas: ecology and life strategies, recent and fossil faunas of Australia and New Zealand, past and present bryozoans from both Antarctic and Arctic seas, geology and palaeontology of bryozoans from Eurasia and North America, fresh water bryozoans around the world, fossil bryozoans of the Mediterranean and Tethyan realms and evolution and diversity of recent species. This volume represents the newest advances made in bryozoological studies during the last three years, and makes a significant contribution to the literature.