Sargassum muticum Sargassum muticum Sargassum muticum, commonly known as Japanese wireweed, is a large brown seaweed of the genus "Sargassum". It is an invasive seaweed with high growth rate (up to 10 cm per day during spring). It has an efficient dispersion thanks to its floats. "Sargassum muticum" is a brown seaweed, normally brown to yellowish with a length up to 10 m. It is an autotroph that uses energy from sunlight. The photosynthesis is facilitated thanks to aerial vesicles which allows the algae to raise to the surface. "Sargassum muticum" is composed of two distinct parts: a perennial part, which contains
Sargassum color and consist of a holdfast, a stipe, and a frond. Oogonia and antheridia occur in conceptacles embedded in receptacles on special branches. Some species have berrylike gas-filled bladders that help the fronds float to promote photosynthesis. Many have a rough, sticky texture that, along with a robust but flexible body, helps it withstand strong water currents. Large, pelagic mats of "Sargassum" in the Sargasso Sea act as one of the only habitats available for ecosystem development; this is because the Sargasso Sea lacks any land boundaries . The Sargassum patches act as a refuge for many species in different