This volume is a record of the proceedings of the IXth International Rotifer Symposium, which was held in Khon Kaen, Thailand, on January 16-23, 2000. The symposium was the first meeting of the international group of rotifer researchers held in Asia. The volume contains reviews and research papers dealing with diverse aspects of scientific research related to Rotifera and their ecology. Some of the topics addressed are: taxonomy and zoogeography, ecology, phylogeny and evolution, physiology, biochemistry and population genetics, aquaculture, and ecotoxicology. This book is special because it contains a unique compilation of contemporary rotifer-related research, and is the eighth of a series of rotifer symposium proceedings published in Developments of Hydrobiology. This update of Rotifera studies will be of great interest to invertebrate zoologists, hydrobiologists, ecologists, and aquaculturists, particularly those interested in freshwater habitats.

The Fifth International Rotifer Symposium was organized by Dr. Claudia Ricci and held in the northern Italian town of Gargnano (Brescia) from September 12-17, 1988. Through the generosity of the Rector of Milano University, a beautiful villa on the shores of Lake Garda was made available to the 83 people from 20 countries who attended the symposium. Ten of these rotifer workers had attended the four previous meetings. Such symposia serve three major functions, the results of which will be apparent in the papers contained in this volume. First, because of the heterogeneity of interests and absence of concurrent sessions, the attendees are exposed to an unusually large variety of research problems, approaches and modes of interpretation. Bridges are thus built between one's own investigations and developments in the field as a whole. Second, the extensive informal interactions that occur outside of the meeting room during coffee breaks, dinners and excursions provide remarkable opportunities for research planning and sharing of results of work in progress. Third, the acquaintances established at these meetings have facilitated interactions during the three-year intervals between symposia. The result has been that visits between laboratories, acquisition of research materials from distant sources and coordination of related investi gations have all been greatly enhanced. A description of the week's events may serve to convey the ambience of the meeting.