Mussel is the common name used for members of several families of bivalvia mollusca, from saltwater and freshwater habitats. Mussels are economically and ecologically important as they play a key role in aquatic environments and are considered to be "ecosystem engineers." In this book, the authors discuss the ecology, life habits and control of mussels. Topics include native and invasive mussels; paralytic shellfish toxins and lipophilic toxins and their interaction with the habitat of mussels in the South Pacific Ocean; mussels as a tool to monitor pollution; bioenergetic model predictions of actual growth and allometric transitions during ontogeny of juvenile blue mussels; the synthesis of vitellogenin in the mussel mytilus galloprovincialis; the Brachidontes solisiannus mussel and its re-colonisation dynamics on a sandstone reef at Pernambuco, Brazil; and mussel farms in the Gulf of Naples.