This book reviews up-to-date knowledge on the biology of sole (Solea senegalensis and S. solea). These flatfish species are increasingly important in Europe both from the ecological and production point of view. This book is divided into two sections: A. general fisheries, aquaculture and engineering overviews; B. physiological, developmental, rhythmic, welfare and genetic aspects which will be of immense interest for the aquaculture industry. Experts, from both academia and research institutes, provide their expertise on sole biology.