Résumé
Hundreds of macroalgal species have been spread outside their natural range by human activities, and many of these introductions are occurring at a worldwide scale. This review considers one of the best-studied and most widespread invasive macroalgae, Sargassum muticum, to determine the traits and processes important in marine invasions and to identify important lines of future research. Particular emphasis is placed on the ecology of S. muticum in its native range and on the four stages of invasion transport, colonization, establishment, and spread integrating taxonomy, invasion history, dispersal, impact, invasiveness and invasibility, and general ecology. Although S. muticum has received a lot of scientific attention, with more than 650 papers on this species, key information on its taxonomy, invasive biology, and evolutionary potential is still lacking. Most previous studies have been local or descriptive or provide circumstantial evidence, and too few have been hypothesis driven. Only by local-scale research conducted in different geographical regions, especially including the native range, and developed in an eco-evolutionary framework, will it be possible to greatly improve our understanding of the complex of factors, traits, and processes involved in macroalgal invasions.