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 muticum observed in temperate environments. "Sargassum muticum" grows from half-tide to infralittoral areas (to a depth of 10 m.). It is fixed on solid substrates like rocks, stones, shells. It is highly tolerant towards temperature and salinity variations. The optimal temperature is between 17 and 20 °C but it tolerates -9 and 30 °C. Originally from Japan, it is thought to have gained worldwide distribution through being transported with Japanese oysters ("Crassostrea gigas"). "Sargassum muticum" was introduced to the Californian coast in the 40's and in Europe in the 70's (The species was first found in the British Isles in the