The present volume contains 21 papers presented at the Seventh International Chrysophyte Symposium 2008 spanning a broad range of topics on chrysophytes and related heterokont organisms. The contributions include ones on ecology, taxonomy, floristic works, phylogeny and evolution, molecular biology, physiology and paleolimnology. Of special interest are a group of papers that use geometric morphometric analyses to address taxonomic, biogeographic and phylogenetic questions related to chrysophytes and other microalgae. Ecological and floristic contributions include ones on lakes from the polar Ural Mountains, the Mesopotamia region of South America, the Pine Barrens of southern New Jersey, and the Swiss Alps. Gene sequences are used to study hidden diversity in Synura and differences between two geographically distinct Heterosigma isolates, and production of polyunsaturated aldehydes is examined in Thalassiosira. Other contributions include ones on mixotrophy, biofilm dynamics, the recent invasion of Mallomonas pseudocoronata into lakes in Sweden, use of cysts in climate change research, paleolimnology of eastern North American lakes, an evaluation of the age of the Hueyatlaco early man site in Mexico, a comparison of the architecture of Mallomonas scale coverings between modern and 40 Ma specimens and bloom dynamics. Papers outlining the establishment of a Wiki for chrysophyte cysts, an on-line database for Eocene chrysophyte fossils, and ideas for preserving specimens in museums round out the volume.