Marine organisms have long provided ideal systems for the study of development. The reasons for this are essentially twofold. Firstly, gametes, zygotes and embryos of many species are relatively accessible, facilitating observation and experimental manipulation. Secondly, the exceptional diversity to be found in the sea allows wide ranging comparative and evolutionary studies. The aim of this meeting was to highlight significant advances in developmental biology research using marine organisms and to bring together workers from a variety of disciplines to encourage cross-fertilization of ideas and comparisons between different systems. Particular attention was paid to new approaches for solving fundamental problems at different levels of complexity and organization. The meeting was organized such that parallel developmental processes in different systems, both animal and plant, could be compared. Sessions covered egg activation/cell cycle control; polarization/early development; embryogenesis/larval development; and the interaction between development and environment. Examples were chosen from a wide range of organisms, including molluscs, echinoderms, asddians, echiuran and polychaete worms, ctenophores, copepods, amphioxus, fish and algae (Brownlee, 1993).