LIFECYCLE (14 partners, 9 countries) will deliver a knowledge-base to improve competitiveness and sustainability of European aquaculture, through a combination of question-problem driven approaches. The focus will be on early developmental events, growth and environmental adaptation throughout the lifecyle, and on the physiology and immunology of key life-stage transitions, such as metamorphosis, smoltification and puberty. To advance current knowledge on mechanisms governing essential biological functions in fish, state-of-the-art physiological research will be combined with functional genomics by leading European research groups. LIFECYCLE will focus on all major life stages of sea bass, sea bream, Atlantic salmon and rainbow trout. For these important aquaculture species, substantial resources and biological information exists which will be exploited and integrated to potentiate the overall impact. Two key conceptual approaches will be taken: 1. Changes in physiological systems at different points during the lifecycle will be studied to establish how early factors impact on later stages. 2. Cross-cutting experiments will address integration and crosstalk between physiological systems. LIFECYCLE is planned to direct research at current production bottlenecks. The knowledge generated about development and growth, adaptation and homeostasis, the immune system, sex differentiation and puberty will have a major impact on alleviating problems linked to abnormal larval development, skeletal deformities, poor growth and energy utilization, mortalities related to life stage transitions, poor environmental performance, and unwanted sexual maturation. The focused dissemination of such knowledge will make the EU aquaculture industry more efficient and stimulate its sustainable expansion. The knowledge-base established will pave way for future advances within fields of stress and disease control, breeding selection, environmental performance and species diversification.